本文是根據最近一份github上很不錯的部署教程所做的驗證部署測試,不同之處在於原教程中是3節點,而這裏共使用了4個節點。Github上的教程地址如下所示,推薦大家參照原作者文章進行自己的實驗。在本文中遇到的一些問題,也已經反饋至github issue或討論中,同時也有很多其他網友反饋遇到或發現的一些問題,其中大部分問題都已經在github教程中得到了校正。
https://github.com/opsnull/follow-me-install-kubernetes-cluster
目錄:
問題記錄
系統初始化配置
創建CA證書和密鑰
部署 kubectl 命令行工具
部署 etcd 集羣
部署flannel網絡
部署 master 節點
部署node節點
驗證集羣功能
部署集羣插件
問題記錄:
開篇先談問題記錄,主要原因是參照github上的教程原文去部署自己的實驗環境的效果會更好,大家瞭解下我遇到過的問題即可,提供一個參考。Github上的教程原文內容詳實、生動,是以部署操作的說明爲主,原理性的知識需要自己另行學習掌握。原文中也曾出現和糾正過一些細微錯誤,盡信書不如無書,遇到問題後不妨查一下其他參考資料中是怎麼說的。本文也只是我的一份過程筆記,供自己後續工作參考。
1、網卡hairpin_mode設置
在準備配置環境的過程中,就要求設置docker網卡的hairpin_mode,不太理解在未安裝docker時爲什麼要求設置這個,且確實無法設置,因爲此時連docker也還沒有安裝。
注:hairpin_mode模式下,虛機或容器間的流量強制要求必須經過物理交換機才能通信。
2、設置系統參數net.bridge.bridge-nf-call-iptables=1(打開iptables管理網橋的功能)
在各節點上執行以下命令:
modprobe br_netfilter
cat > /etc/sysctl.d/kubernetes.conf <
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv4.ip_forward=1
EOF
sysctl -p /etc/sysctl.d/kubernetes.conf
原文中把modprobe br_netfilter放在最後執行的,實際情況是應該首先執行這條命令。
3、授予 kubernetes 證書訪問 kubelet API 的權限的命令的執行順序錯誤
應該在成功啓動了kube-apiserver服務後再執行該命令。
4、在部署kube-apiserver服務中,製作密鑰的證書請求中使用了無法解析的域名kubernetes.default.svc.cluster.local.
該問題已經確認爲是go v1.9中的域名語法校驗解析bug。在6.29號的最新版本的部署材料中已經發現和糾正了該問題。但此故障引發的coreDNS部署失敗並報以下錯誤,已經摺騰了我2天時間尋求答案!
E0628 08:10:41.256264 1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:319: Failed to list *v1.Namespace: Get https://10.254.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: tls: failed to parse certificate from server: x509: cannot parse dnsName "kubernetes.default.svc.cluster.local."
關於該bug的修復說明:
5、關於怎麼使用admin密鑰訪問api接口
下面是正確的方式:
curl -sSL --cacert /etc/kubernetes/cert/ca.pem --cert /home/k8s/admin.pem --key /home/k8s/admin-key.pem https://172.16.10.100:6443/api/v1/endpoints
注:原文中因密鑰文件未指定爲絕對路徑,會導致無法找到而報錯。
1、系統初始化配置
ssh登錄信息:
kube-node1,localhost:2222
kube-node2,localhost:2200
kube-node3,localhost:2201
kube-server,localhost:2202
修改每臺機器的 /etc/hosts 文件,添加主機名和 IP 的對應關係:
172.16.10.100 kube-server
172.16.10.101 kube-node1
172.16.10.102 kube-node2
172.16.10.103 kube-node3
在每臺機器上添加 k8s 賬戶,可以無密碼 sudo:
useradd -m k8s
visudo
在末尾添加下面一行
k8s ALL=(ALL) NOPASSWD: ALL
在所有node節點機器上添加 docker 賬戶,將 k8s 賬戶添加到 docker 組中,同時配置 dockerd 參數:
useradd -m docker
gpasswd -a k8s docker
mkdir -p /etc/docker/
cat /etc/docker/daemon.json
{
"registry-mirrors": ["https://hub-mirror.c.163.com", "https://docker.mirrors.ustc.edu.cn"],
"max-concurrent-downloads": 20
}
設置 kube-server 可以無密碼登錄所有節點的 k8s 和 root 賬戶:
[k8s@kube-server k8s]$ ssh-keygen -t rsa
[k8s@kube-server k8s]$ ssh-copy-id root@kube-node1
[k8s@kube-server k8s]$ ssh-copy-id root@kube-node2
[k8s@kube-server k8s]$ ssh-copy-id root@kube-node3
[k8s@kube-server k8s]$ ssh-copy-id k8s@kube-node1
[k8s@kube-server k8s]$ ssh-copy-id k8s@kube-node2
[k8s@kube-server k8s]$ ssh-copy-id k8s@kube-node3
在每臺機器上將可執行文件路徑 /opt/k8s/bin 添加到 PATH 變量中:
[root@kube-server ~]# echo 'PATH=/opt/k8s/bin:$PATH:$HOME/bin:$JAVA_HOME/bin' >>/root/.bashrc
[root@kube-server ~]# su - k8s
[k8s@kube-server ~]$ echo 'PATH=/opt/k8s/bin:$PATH:$HOME/bin:$JAVA_HOME/bin' >>~/.bashrc
在每臺機器上安裝依賴包:
yum install -y epel-release
yum install -y conntrack ipvsadm ipset jq sysstat curl iptables
在每臺機器上關閉防火牆:
systemctl stop firewalld
systemctl disable firewalld
iptables -F && iptables -X && iptables -F -t nat && iptables -X -t nat
iptables -P FORWARD ACCEPT
在每臺機器上關閉swap分區,k8s從v1.8版本開始默認要求關閉swap,這樣做的主要目的是保證性能:
swapoff -a
同時編輯下/etc/fstab文件,註釋掉swap分區。
注:也可以選擇通過爲kubelet將參數 --fail-swap-on 設置爲 false 來忽略 swap on
設置系統參數
net.bridge.bridge-nf-call-iptables=1(打開iptables管理網橋的功能)
在各節點上執行以下命令:
modprobe br_netfilter
cat > /etc/sysctl.d/kubernetes.conf <
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv4.ip_forward=1
vm.swappiness=0
EOF
sysctl -p /etc/sysctl.d/kubernetes.conf
使用k8s用戶在每臺機器上創建目錄:
sudo mkdir -p /opt/k8s/bin
sudo chown -R k8s /opt/k8s
sudo sudo mkdir -p /etc/kubernetes/cert
sudo chown -R k8s /etc/kubernetes
sudo mkdir -p /etc/etcd/cert
sudo chown -R k8s /etc/etcd/cert
sudo mkdir -p /var/lib/etcd && chown -R k8s /etc/etcd/cert
後續的部署步驟將使用下面定義的全局環境變量,請根據自己的機器、網絡情況修改:
!/usr/bin/bash
生成 EncryptionConfig 所需的加密 key
ENCRYPTION_KEY=$(head -c 32 /dev/urandom | base64)
最好使用 當前未用的網段 來定義服務網段和 Pod 網段
服務網段,部署前路由不可達,部署後集羣內路由可達(kube-proxy 和 ipvs 保證)
SERVICE_CIDR="10.254.0.0/16"
Pod 網段,建議 /16 段地址,部署前路由不可達,部署後集羣內路由可達(flanneld 保證)
CLUSTER_CIDR="172.30.0.0/16"
服務端口範圍 (NodePort Range)
export NODE_PORT_RANGE="8400-9000"
集羣各機器 IP 數組
export NODE_IPS=(172.16.10.101 172.16.10.102 172.16.10.103)
集羣各 IP 對應的 主機名數組
export NODE_NAMES=(kube-node1 kube-node2 kube-node3)
kube-apiserver 節點 IP
export MASTER_IP=172.16.10.100
kube-apiserver https 地址
export KUBE_APISERVER="https://${MASTER_IP}:6443"
etcd 集羣服務地址列表
export ETCD_ENDPOINTS="https://172.16.10.101:2379,https://172.16.10.102:2379,https://172.16.10.103:2379"
etcd 集羣間通信的 IP 和端口
export ETCD_NODES="kube-node1=https://172.16.10.101:2380,kube-node2=https://172.16.10.102:2380,kube-node3=https://172.16.10.103:2380"
flanneld 網絡配置前綴
export FLANNEL_ETCD_PREFIX="/kubernetes/network"
kubernetes 服務 IP (一般是 SERVICE_CIDR 中第一個IP)
export CLUSTER_KUBERNETES_SVC_IP="10.254.0.1"
集羣 DNS 服務 IP (從 SERVICE_CIDR 中預分配)
export CLUSTER_DNS_SVC_IP="10.254.0.2"
集羣 DNS 域名
export CLUSTER_DNS_DOMAIN="cluster.local."
將二進制目錄 /opt/k8s/bin 加到 PATH 中
export PATH=/opt/k8s/bin:$PATH
將上面內容保存爲/opt/k8s/bin/environment.sh,分發各節點。
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p /opt/k8s/bin && chown -R k8s /opt/k8s/bin"
scp /opt/k8s/bin/environment.sh k8s@${node_ip}:/opt/k8s/bin/environment.sh
done
2、創建CA證書和密鑰
使用 CloudFlare 的 PKI 工具集 cfssl 創建所有證書。
安裝 cfssl 工具集
sudo mkdir -p /opt/k8s/cert && sudo chown -R k8s /opt/k8s && cd /opt/k8s
wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
mv cfssl_linux-amd64 /opt/k8s/bin/cfssl
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
mv cfssljson_linux-amd64 /opt/k8s/bin/cfssljson
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
mv cfssl-certinfo_linux-amd64 /opt/k8s/bin/cfssl-certinfo
chmod +x /opt/k8s/bin/*
export PATH=/opt/k8s/bin:$PATH
創建根證書 (CA)
CA 配置文件用於配置根證書的使用場景 (profile) 和具體參數 (usage,過期時間、服務端認證、客戶端認證、加密等),後續在簽名其它證書時需要指定特定場景。
cat > ca-config.json <
{
"signing": {
"default": {
"expiry": "87600h"
},
"profiles": {
"kubernetes": {
"usages": [
"signing",
"key encipherment",
"server auth",
"client auth"
],
"expiry": "87600h"
}
}
}
}
EOF
signing:表示該證書可用於簽名其它證書,生成的 ca.pem 證書中 CA=TRUE;
server auth:表示 client 可以用該該證書對 server 提供的證書進行驗證;
client auth:表示 server 可以用該該證書對 client 提供的證書進行驗證;
創建證書籤名請求文件
cat > ca-csr.json <
{
"CN": "kubernetes",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "testcorp"
}
]
}
EOF
CN:Common Name,kube-apiserver 從證書中提取該字段作爲請求的用戶名 (User Name),瀏覽器使用該字段驗證網站是否合法;
O:Organization,kube-apiserver 從證書中提取該字段作爲請求用戶所屬的組 (Group);
kube-apiserver 將提取的 User、Group (kubernetes.k8s)作爲 RBAC 授權的用戶標識;
生成 CA 證書和私鑰
[k8s@kube-server ~]$ cfssl gencert -initca ca-csr.json | cfssljson -bare ca
2018/06/25 13:45:47 [INFO] generating a new CA key and certificate from CSR
2018/06/25 13:45:47 [INFO] generate received request
2018/06/25 13:45:47 [INFO] received CSR
2018/06/25 13:45:47 [INFO] generating key: rsa-2048
2018/06/25 13:45:47 [INFO] encoded CSR
2018/06/25 13:45:47 [INFO] signed certificate with serial number 333080208048507116448165428577682216785536827857
[k8s@kube-server ~]$ ls ca*
ca-config.json ca.csr ca-csr.json ca-key.pem ca.pem
[k8s@kube-server ~]$
分發證書文件
將生成的 CA 證書、祕鑰文件、配置文件拷貝到所有節點的 /etc/kubernetes/cert 目錄下:
source /opt/k8s/bin/environment.sh # 導入 NODE_IPS 環境變量
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp ca*.pem ca-config.json k8s@${node_ip}:/etc/kubernetes/cert
done
3、部署 kubectl 命令行工具
kubectl 默認從 ~/.kube/config 文件讀取 kube-apiserver 地址、證書、用戶名等信息。
下載和分發 kubectl 二進制文件
下載和解壓:
wget https://dl.k8s.io/v1.10.4/kubernetes-client-linux-amd64.tar.gz
tar -xzvf kubernetes-client-linux-amd64.tar.gz
分發到所有使用 kubectl 的節點:
source /opt/k8s/bin/environment.sh # 導入 NODE_IPS 環境變量
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp kubernetes/client/bin/kubectl k8s@${node_ip}:/opt/k8s/bin/
ssh k8s@${node_ip} "chmod +x /opt/k8s/bin/*"
done
cp kubernetes/client/bin/kubectl /opt/k8s/bin/
chmod +x /opt/k8s/bin/*
創建 admin 證書和私鑰
kubectl 與 apiserver https 安全端口通信,apiserver 對提供的證書進行認證和授權。
kubectl 作爲集羣的管理工具,需要被授予最高權限。這裏創建具有最高權限的 admin 證書。
創建證書籤名請求:
cat > admin-csr.json <
{
"CN": "admin",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "system:masters",
"OU": "testcorp"
}
]
}
EOF
O 爲 system:masters,kube-apiserver 收到該證書後將請求的 Group 設置爲 system:masters;
預定義的 ClusterRoleBinding cluster-admin 將 Group system:masters 與 Role cluster-admin 綁定,該 Role 授予所有 API的權限;
該證書只會被 kubectl 當做 client 證書使用,所以 hosts 字段爲空;
生成證書和私鑰:
cfssl gencert -ca=/etc/kubernetes/cert/ca.pem -ca-key=/etc/kubernetes/cert/ca-key.pem -config=/etc/kubernetes/cert/ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin
ls admin*
創建 kubeconfig 文件
kubeconfig 爲 kubectl 的配置文件,包含訪問 apiserver 的所有信息,如 apiserver 地址、CA 證書和自身使用的證書。
source /opt/k8s/bin/environment.sh
設置集羣參數
kubectl config set-cluster kubernetes \
--certificate-authority=/etc/kubernetes/cert/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=kubectl.kubeconfig
設置客戶端認證參數
kubectl config set-credentials admin \
--client-certificate=admin.pem \
--client-key=admin-key.pem \
--embed-certs=true \
--kubeconfig=kubectl.kubeconfig
設置上下文參數
kubectl config set-context kubernetes \
--cluster=kubernetes \
--user=admin \
--kubeconfig=kubectl.kubeconfig
設置默認上下文
kubectl config use-context kubernetes --kubeconfig=kubectl.kubeconfig
--certificate-authority:驗證 kube-apiserver 證書的根證書;
--client-certificate、--client-key:剛生成的 admin 證書和私鑰,連接 kube-apiserver 時使用;
--embed-certs=true:將 ca.pem 和 admin.pem 證書內容嵌入到生成的 kubectl.kubeconfig 文件中(不加時,寫入的是證書文件路徑);
分發 kubeconfig 文件
分發到所有使用 kubelet 命令的節點:
source /opt/k8s/bin/environment.sh # 導入 NODE_IPS 環境變量
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh k8s@${node_ip} "mkdir -p ~/.kube"
scp kubectl.kubeconfig k8s@${node_ip}:~/.kube/config
ssh root@${node_ip} "mkdir -p ~/.kube"
scp kubectl.kubeconfig root@${node_ip}:~/.kube/config
done
cp kubectl.kubeconfig /home/k8s/.kube/config
sudo mkdir -p /root/.kube
sudo cp kubectl.kubeconfig /root/.kube/config
保存到用戶的 ~/.kube/config 文件。
4、部署 etcd 集羣
我們在kube-node1, kube-node2, kube-node3上面部署一套高可用的etcd服務集羣。
下載和分發 etcd 二進制文件
到 https://github.com/coreos/etcd/releases 頁面下載最新版本的發佈包:
wget https://github.com/coreos/etcd/releases/download/v3.3.7/etcd-v3.3.7-linux-amd64.tar.gz
tar -xvf etcd-v3.3.7-linux-amd64.tar.gz
分發二進制文件到集羣所有節點
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp etcd-v3.3.7-linux-amd64/etcd* k8s@${node_ip}:/opt/k8s/bin
ssh k8s@${node_ip} "chmod +x /opt/k8s/bin/*"
done
創建 etcd 證書和私鑰
創建證書籤名請求:
cat > etcd-csr.json <
{
"CN": "etcd",
"hosts": [
"127.0.0.1",
"172.16.10.101",
"172.16.10.102",
"172.16.10.103"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "testcorp"
}
]
}
EOF
hosts 字段指定授權使用該證書的 etcd 節點 IP 或域名列表,這裏將 etcd 集羣的三個節點 IP 都列在其中。
生成證書和私鑰:
cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
-ca-key=/etc/kubernetes/cert/ca-key.pem \
-config=/etc/kubernetes/cert/ca-config.json \
-profile=kubernetes etcd-csr.json | cfssljson -bare etcd
分發生成的證書和私鑰到各 etcd 節點:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p /etc/etcd/cert && chown -R k8s /etc/etcd/cert"
scp etcd*.pem k8s@${node_ip}:/etc/etcd/cert/
done
創建 etcd 的 systemd unit 模板文件
source /opt/k8s/bin/environment.sh
cat > etcd.service.template <
After=network.target
After=network-online.target
Wants=network-online.target
Documentation=https://github.com/coreos
[Service]
User=k8s
Type=notify
WorkingDirectory=/var/lib/etcd/
ExecStart=/opt/k8s/bin/etcd \
--data-dir=/var/lib/etcd \
--name=##NODE_NAME## \
--cert-file=/etc/etcd/cert/etcd.pem \
--key-file=/etc/etcd/cert/etcd-key.pem \
--trusted-ca-file=/etc/kubernetes/cert/ca.pem \
--peer-cert-file=/etc/etcd/cert/etcd.pem \
--peer-key-file=/etc/etcd/cert/etcd-key.pem \
--peer-trusted-ca-file=/etc/kubernetes/cert/ca.pem \
--peer-client-cert-auth \
--client-cert-auth \
--listen-peer-urls=https://##NODE_IP##:2380 \
--initial-advertise-peer-urls=https://##NODE_IP##:2380 \
--listen-client-urls=https://##NODE_IP##:2379,http://127.0.0.1:2379 \
--advertise-client-urls=https://##NODE_IP##:2379 \
--initial-cluster-token=etcd-cluster-0 \
--initial-cluster=${ETCD_NODES} \
--initial-cluster-state=new
Restart=on-failure
RestartSec=5
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
User:指定以 k8s 賬戶運行;
WorkingDirectory、--data-dir:指定工作目錄和數據目錄爲 /var/lib/etcd,需在啓動服務前創建這個目錄;
--name:指定節點名稱,當 --initial-cluster-state 值爲 new 時,--name 的參數值必須位於 --initial-cluster 列表中;
--cert-file、--key-file:etcd server 與 client 通信時使用的證書和私鑰;
--peer-client-cert-auth、--client-cert-auth:啓用與client的加密通信功能;
--trusted-ca-file:簽名 client 證書的 CA 證書,用於驗證 client 證書;
--peer-cert-file、--peer-key-file:etcd 與 peer 通信使用的證書和私鑰;
--peer-trusted-ca-file:簽名 peer 證書的 CA 證書,用於驗證 peer 證書;
爲各節點創建和分發 etcd systemd unit 文件
替換模板文件中的變量,爲各節點創建 systemd unit 文件:
source /opt/k8s/bin/environment.sh
for (( i=0; i < 3; i++ ))
do
sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" etcd.service.template > etcd-${NODE_IPS[i]}.service
done
ls *.service
NODE_NAMES 和 NODE_IPS 爲相同長度的 bash 數組,分別爲節點名稱和對應的 IP。
分發生成的 systemd unit 文件:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p /var/lib/etcd && chown -R k8s /var/lib/etcd" # 創建 etcd 數據目錄和工作目錄
scp etcd-${node_ip}.service root@${node_ip}:/etc/systemd/system/etcd.service
done
文件重命名爲 etcd.service。
啓動 etcd 服務
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "source /opt/k8s/bin/environment.sh && systemctl daemon-reload && systemctl enable etcd && systemctl start etcd"
done
etcd 進程首次啓動時會等待其它節點的 etcd 加入集羣,命令 systemctl start etcd 會卡住一段時間,爲正常現象。
檢查啓動結果
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh k8s@${node_ip} "systemctl status etcd|grep Active"
done
172.16.10.101
Active: active (running) since Mon 2018-06-25 17:17:52 UTC; 58s ago
172.16.10.102
Active: active (running) since Mon 2018-06-25 17:17:52 UTC; 58s ago
172.16.10.103
Active: active (running) since Mon 2018-06-25 17:17:58 UTC; 53s ago
驗證服務狀態
部署完 etcd 集羣后,在任一 etc 節點上執行如下命令:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ETCDCTL_API=3 /opt/k8s/bin/etcdctl \
--endpoints=https://${node_ip}:2379 \
--cacert=/etc/kubernetes/cert/ca.pem \
--cert=/etc/etcd/cert/etcd.pem \
--key=/etc/etcd/cert/etcd-key.pem endpoint health
done
172.16.10.101
https://172.16.10.101:2379 is healthy: successfully committed proposal: took = 1.918083ms
172.16.10.102
https://172.16.10.102:2379 is healthy: successfully committed proposal: took = 2.779171ms
172.16.10.103
https://172.16.10.103:2379 is healthy: successfully committed proposal: took = 2.684327ms
輸出均爲 healthy 時表示集羣服務正常。
5、部署flannel網絡
下載和分發 flanneld 二進制文件
到 https://github.com/coreos/flannel/releases 頁面下載最新版本的發佈包:
mkdir flannel
wget https://github.com/coreos/flannel/releases/download/v0.10.0/flannel-v0.10.0-linux-amd64.tar.gz
tar -xzvf flannel-v0.10.0-linux-amd64.tar.gz -C flannel
分發 flanneld 二進制文件到集羣所有節點:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp flannel/{flanneld,mk-docker-opts.sh} k8s@${node_ip}:/opt/k8s/bin/
ssh k8s@${node_ip} "chmod +x /opt/k8s/bin/*"
done
此爲在kube-server節點上的操作,所以還要向本節點複製一份:
cp flannel/flanneld flannel/mk-docker-opts.sh /opt/k8s/bin/
chmod +x /opt/k8s/bin/*
創建 flannel 證書和私鑰
flannel 從 etcd 集羣存取網段分配信息,而 etcd 集羣啓用了雙向 x509 證書認證,所以需要爲 flanneld 生成證書和私鑰。
創建證書籤名請求:
cat > flanneld-csr.json <
{
"CN": "flanneld",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "testcorp"
}
]
}
EOF
該證書只會被 kubectl 當做 client 證書使用,所以 hosts 字段爲空。
生成證書和私鑰:
cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
-ca-key=/etc/kubernetes/cert/ca-key.pem \
-config=/etc/kubernetes/cert/ca-config.json \
-profile=kubernetes flanneld-csr.json | cfssljson -bare flanneld
ls flanneld*pem
將生成的證書和私鑰分發到所有節點(master 和 worker):
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p /etc/flanneld/cert && chown -R k8s /etc/flanneld"
scp flanneld*.pem k8s@${node_ip}:/etc/flanneld/cert
done
給kube-server自身也要分發一份:
sudo mkdir -p /etc/flanneld/cert &&sudo chown -R k8s /etc/flanneld
cp flanneld*.pem /etc/flanneld/cert
向 etcd 寫入集羣 Pod 網段信息
注意:本步驟只需在某一個node節點上執行一次。
source /opt/k8s/bin/environment.sh
etcdctl \
--endpoints=${ETCD_ENDPOINTS} \
--ca-file=/etc/kubernetes/cert/ca.pem \
--cert-file=/etc/flanneld/cert/flanneld.pem \
--key-file=/etc/flanneld/cert/flanneld-key.pem \
set ${FLANNEL_ETCD_PREFIX}/config '{"Network":"'${CLUSTER_CIDR}'", "SubnetLen": 24, "Backend": {"Type": "vxlan"}}'
預期輸出類似:
{"Network":"172.30.0.0/16", "SubnetLen": 24, "Backend": {"Type": "vxlan"}}
flanneld 當前版本 (v0.10.0) 不支持 etcd v3,故使用 etcd v2 API 寫入配置 key 和網段數據;
寫入的 Pod 網段 ${CLUSTER_CIDR} 必須是 /16 段地址,必須與 kube-controller-manager 的 --cluster-cidr 參數值一致;
創建 flanneld 的 systemd unit 文件
source /opt/k8s/bin/environment.sh
export IFACE=enp0s8 # 節點間互聯的網絡接口名稱
cat > flanneld.service << EOF
[Unit]
Description=Flanneld overlay address etcd agent
After=network.target
After=network-online.target
Wants=network-online.target
After=etcd.service
Before=docker.service
[Service]
Type=notify
ExecStart=/opt/k8s/bin/flanneld \
-etcd-cafile=/etc/kubernetes/cert/ca.pem \
-etcd-certfile=/etc/flanneld/cert/flanneld.pem \
-etcd-keyfile=/etc/flanneld/cert/flanneld-key.pem \
-etcd-endpoints=${ETCD_ENDPOINTS} \
-etcd-prefix=${FLANNEL_ETCD_PREFIX} \
-iface=${IFACE}
ExecStartPost=/opt/k8s/bin/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/docker
Restart=on-failure
[Install]
WantedBy=multi-user.target
RequiredBy=docker.service
EOF
mk-docker-opts.sh 腳本將分配給 flanneld 的 Pod 子網網段信息寫入 /run/flannel/docker 文件,後續 docker 啓動時使用這個文件中的環境變量配置 docker0 網橋;
flanneld 使用系統缺省路由所在的接口與其它節點通信,對於有多個網絡接口(如內網和公網)的節點,可以用 -iface參數指定通信接口;
flanneld 運行時需要 root 權限;
分發 flanneld systemd unit 文件到所有節點
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp flanneld.service root@${node_ip}:/etc/systemd/system/
done
也要包括kube-server節點自身:
sudo cp flanneld.service /etc/systemd/system/
啓動 flanneld 服務
在kube-server節點上:
sudo systemctl daemon-reload && sudo systemctl enable flanneld && sudo systemctl start flanneld
啓動其它node節點上的flanneld服務,繼續在kube-server上執行:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable flanneld && systemctl start flanneld"
done
檢查啓動結果
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh k8s@${node_ip} "systemctl status flanneld|grep Active"
done
檢查分配給各 flanneld 的 Pod 網段信息
在一個node節點上查看集羣 Pod 網段(/16):
source /opt/k8s/bin/environment.sh
etcdctl \
--endpoints=${ETCD_ENDPOINTS} \
--ca-file=/etc/kubernetes/cert/ca.pem \
--cert-file=/etc/flanneld/cert/flanneld.pem \
--key-file=/etc/flanneld/cert/flanneld-key.pem \
get ${FLANNEL_ETCD_PREFIX}/config
輸出:
{"Network":"172.30.0.0/16", "SubnetLen": 24, "Backend": {"Type": "vxlan"}}
查看已分配的 Pod 子網段列表(/24):
source /opt/k8s/bin/environment.sh
etcdctl \
--endpoints=${ETCD_ENDPOINTS} \
--ca-file=/etc/kubernetes/cert/ca.pem \
--cert-file=/etc/flanneld/cert/flanneld.pem \
--key-file=/etc/flanneld/cert/flanneld-key.pem \
ls ${FLANNEL_ETCD_PREFIX}/subnets
輸出:
/kubernetes/network/subnets/172.30.46.0-24
/kubernetes/network/subnets/172.30.49.0-24
/kubernetes/network/subnets/172.30.7.0-24
/kubernetes/network/subnets/172.30.48.0-24
查看某一 Pod 網段對應的節點 IP 和 flannel 接口地址:
source /opt/k8s/bin/environment.sh
etcdctl \
--endpoints=${ETCD_ENDPOINTS} \
--ca-file=/etc/kubernetes/cert/ca.pem \
--cert-file=/etc/flanneld/cert/flanneld.pem \
--key-file=/etc/flanneld/cert/flanneld-key.pem \
get ${FLANNEL_ETCD_PREFIX}/subnets/172.30.46.0-24
輸出:
{"PublicIP":"172.16.10.100","BackendType":"vxlan","BackendData":{"VtepMAC":"92:dc:8d:eb:f2:bf"}}
驗證各節點能通過 Pod 網段互通
在各節點上部署 flannel 後,檢查是否創建了 flannel 接口(名稱可能爲 flannel0、flannel.0、flannel.1 等):
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh ${node_ip} "/usr/sbin/ip addr show flannel.1|grep -w inet"
done
輸出:
172.16.10.101
inet 172.30.49.0/32 scope global flannel.1
172.16.10.102
inet 172.30.7.0/32 scope global flannel.1
172.16.10.103
inet 172.30.48.0/32 scope global flannel.1
在各節點上 ping 所有 flannel 接口 IP,確保能通:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh ${node_ip} "ping -c 1 172.30.46.0"
ssh ${node_ip} "ping -c 1 172.30.49.0"
ssh ${node_ip} "ping -c 1 172.30.7.0"
ssh ${node_ip} "ping -c 1 172.30.48.0"
done
6、部署 master 節點
kubernetes master 節點運行如下組件:
kube-apiserver
kube-scheduler
kube-controller-manager
這 3 個組件均可以以集羣模式運行,通過 leader 選舉產生一個工作進程,其它進程處於阻塞模式。
下載最新版本的二進制文件
從 CHANGELOG頁面 下載 server tarball 文件。
wget https://dl.k8s.io/v1.10.4/kubernetes-server-linux-amd64.tar.gz
tar -xzvf kubernetes-server-linux-amd64.tar.gz
將二進制文件拷貝到所有 master 節點
因爲我們這裏只有一個master節點,所以:
cp server/bin/* /opt/k8s/bin/
chmod +x /opt/k8s/bin/*
6.1 部署 kube-apiserver 組件
創建 kubernetes 證書和私鑰
創建證書籤名請求:
source /opt/k8s/bin/environment.sh
cat > kubernetes-csr.json <
{
"CN": "kubernetes",
"hosts": [
"127.0.0.1",
"172.16.10.100",
"10.254.0.1",
"kubernetes",
"kubernetes.default",
"kubernetes.default.svc",
"kubernetes.default.svc.cluster",
"kubernetes.default.svc.cluster.local"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "testcorp"
}
]
}
EOF
hosts 字段指定授權使用該證書的 IP 或域名列表,這裏列出了 apiserver 節點 IP、kubernetes 服務 IP 和域名;
域名最後字符不能是 .(如不能爲 kubernetes.default.svc.cluster.local.),否則解析時失敗,提示: x509: cannot parse dnsName "kubernetes.default.svc.cluster.local.";
如果使用非 cluster.local 域名,如 opsnull.com,則需要修改域名列表中的最後兩個域名爲:kubernetes.default.svc.opsnull、kubernetes.default.svc.opsnull.com
kubernetes 服務 IP 是 apiserver 自動創建的,一般是 --service-cluster-ip-range 參數指定的網段的第一個IP
生成證書和私鑰:
cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
-ca-key=/etc/kubernetes/cert/ca-key.pem \
-config=/etc/kubernetes/cert/ca-config.json \
-profile=kubernetes kubernetes-csr.json | cfssljson -bare kubernetes
ls kubernetes*
將生成的證書和私鑰文件拷貝到 master 節點:
sudo mkdir -p /etc/kubernetes/cert/ && sudo chown -R k8s /etc/kubernetes/cert/
cp kubernetes*.pem /etc/kubernetes/cert/
注:k8s 賬戶可以讀寫 /etc/kubernetes/cert/ 目錄;
創建加密配置文件
source /opt/k8s/bin/environment.sh
cat > encryption-config.yaml <
kind: EncryptionConfig
apiVersion: v1
resources:
- resources:
- secrets
providers:
- aescbc:
keys:
- name: key1
secret: ${ENCRYPTION_KEY}
- identity: {}
EOF
將加密配置文件拷貝到 master 節點的 /etc/kubernetes 目錄下:
cp encryption-config.yaml /etc/kubernetes/
創建和分發 kube-apiserver systemd unit 文件
source /opt/k8s/bin/environment.sh
cat > kube-apiserver.service <
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
[Service]
ExecStart=/opt/k8s/bin/kube-apiserver \
--enable-admission-plugins=Initializers,NamespaceLifecycle,NodeRestriction,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota \
--anonymous-auth=false \
--experimental-encryption-provider-config=/etc/kubernetes/encryption-config.yaml \
--advertise-address=${MASTER_IP} \
--bind-address=${MASTER_IP} \
--insecure-port=0 \
--authorization-mode=Node,RBAC \
--runtime-config=api/all \
--enable-bootstrap-token-auth \
--service-cluster-ip-range=${SERVICE_CIDR} \
--service-node-port-range=${NODE_PORT_RANGE} \
--tls-cert-file=/etc/kubernetes/cert/kubernetes.pem \
--tls-private-key-file=/etc/kubernetes/cert/kubernetes-key.pem \
--client-ca-file=/etc/kubernetes/cert/ca.pem \
--kubelet-client-certificate=/etc/kubernetes/cert/kubernetes.pem \
--kubelet-client-key=/etc/kubernetes/cert/kubernetes-key.pem \
--service-account-key-file=/etc/kubernetes/cert/ca-key.pem \
--etcd-cafile=/etc/kubernetes/cert/ca.pem \
--etcd-certfile=/etc/kubernetes/cert/kubernetes.pem \
--etcd-keyfile=/etc/kubernetes/cert/kubernetes-key.pem \
--etcd-servers=${ETCD_ENDPOINTS} \
--enable-swagger-ui=true \
--allow-privileged=true \
--apiserver-count=3 \
--audit-log-maxage=30 \
--audit-log-maxbackup=3 \
--audit-log-maxsize=100 \
--audit-log-path=/var/log/audit.log \
--event-ttl=1h \
--v=2
Restart=on-failure
RestartSec=5
Type=notify
User=k8s
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
--experimental-encryption-provider-config:啓用加密特性;
--authorization-mode=Node,RBAC: 開啓 Node 和 RBAC 授權模式,拒絕未授權的請求;
--enable-admission-plugins:啓用 ServiceAccount 和 NodeRestriction;
--service-account-key-file:簽名 ServiceAccount Token 的公鑰文件,kube-controller-manager 的 --service-account-private-key-file 指定私鑰文件,兩者配對使用;
--tls-*-file:指定 apiserver 使用的證書、私鑰和 CA 文件。--client-ca-file 用於驗證 client (kue-controller-manager、kube-scheduler、kubelet、kube-proxy 等)請求所帶的證書;
--kubelet-client-certificate、--kubelet-client-key:如果指定,則使用 https 訪問 kubelet APIs;需要爲 kubernete 用戶定義 RBAC 規則,否則無權訪問 kubelet API;
--bind-address: 不能爲 127.0.0.1,否則外界不能訪問它的安全端口 6443;
--insecure-port=0:關閉監聽非安全端口(8080);
--service-cluster-ip-range: 指定 Service Cluster IP 地址段;
--service-node-port-range: 指定 NodePort 的端口範圍;
--runtime-config=api/all=true: 啓用所有版本的 APIs,如 autoscaling/v2alpha1;
--enable-bootstrap-token-auth:啓用 kubelet bootstrap 的 token 認證;
--apiserver-count=3:指定集羣運行模式,多臺 kube-apiserver 會通過 leader 選舉產生一個工作節點,其它節點處於阻塞狀態;
User=k8s:使用 k8s 賬戶運行;
分發 systemd uint 文件到 master 節點:
sudo cp kube-apiserver.service /etc/systemd/system/
啓動 kube-apiserver 服務
sudo su -
mkdir -p /var/run/kubernetes && chown -R k8s /var/run/kubernetes
systemctl daemon-reload && systemctl enable kube-apiserver && systemctl start kube-apiserver
檢查下服務狀態:
[k8s@kube-server ~]$ sudo systemctl status kube-apiserver |grep 'Active:'
Active: active (running) since Tue 2018-06-26 03:38:43 UTC; 4min 14s ago
授予 kubernetes 證書訪問 kubelet API 的權限
在執行 kubectl exec、run、logs 等命令時,apiserver 會轉發到 kubelet。這裏定義 RBAC 規則,授權 apiserver 調用 kubelet API。
[k8s@kube-server ~]$ source /opt/k8s/bin/environment.sh
[k8s@kube-server ~]$ kubectl create clusterrolebinding kube-apiserver:kubelet-apis --clusterrole=system:kubelet-api-admin --user kubernetes
clusterrolebinding.rbac.authorization.k8s.io "kube-apiserver:kubelet-apis" created
打印 kube-apiserver 寫入 etcd 的數據
source /opt/k8s/bin/environment.sh
ETCDCTL_API=3 etcdctl \
--endpoints=${ETCD_ENDPOINTS} \
--cacert=/etc/kubernetes/cert/ca.pem \
--cert=/etc/etcd/cert/etcd.pem \
--key=/etc/etcd/cert/etcd-key.pem \
get /registry/ --prefix --keys-only
檢查集羣信息
[k8s@kube-server ~]$ kubectl cluster-info
Kubernetes master is running at https://172.16.10.100:6443
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
[k8s@kube-server ~]$ kubectl get all --all-namespaces
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default service/kubernetes ClusterIP 10.254.0.1 443/TCP 49m
[k8s@kube-server ~]$ kubectl get componentstatuses
NAME STATUS MESSAGE ERROR
scheduler Unhealthy Get http://127.0.0.1:10251/healthz: dial tcp 127.0.0.1:10251: getsockopt: connection refused
controller-manager Unhealthy Get http://127.0.0.1:10252/healthz: dial tcp 127.0.0.1:10252: getsockopt: connection refused
etcd-1 Healthy {"health":"true"}
etcd-2 Healthy {"health":"true"}
etcd-0 Healthy {"health":"true"}
注意:
- 如果執行 kubectl 命令式時輸出如下錯誤信息,則說明使用的 ~/.kube/config 文件不對,請切換到正確的賬戶後再執行該命令:
The connection to the server localhost:8080 was refused - did you specify the right host or port?
- 執行 kubectl get componentstatuses 命令時,apiserver 默認向 127.0.0.1 發送請求。當 controller-manager、scheduler 以集羣模式運行時,有可能和 kube-apiserver 不在一臺機器上,這時 controller-manager 或 scheduler 的狀態爲 Unhealthy,但實際上它們工作正常。
檢查 kube-apiserver 監聽的端口
[k8s@kube-server ~]$ sudo netstat -lnpt|grep kube
tcp 0 0 172.16.10.100:6443 0.0.0.0:* LISTEN 11066/kube-apiserve
6443: 接收 https 請求的安全端口,對所有請求做認證和授權;
由於關閉了非安全端口,故沒有監聽 8080;
6.2 部署高可用 kube-controller-manager 集羣
該集羣包含 3 個節點,我們使用node1、node2、node3來搭建,啓動後將通過競爭選舉機制產生一個 leader 節點,其它節點爲阻塞狀態。當 leader 節點不可用後,剩餘節點將再次進行選舉產生新的 leader 節點,從而保證服務的可用性。
爲保證通信安全,本文檔先生成 x509 證書和私鑰,kube-controller-manager 在如下兩種情況下使用該證書:
- 與 kube-apiserver 的安全端口通信時;
- 在安全端口(https,10252) 輸出 prometheus 格式的 metrics;
創建 kube-controller-manager 證書和私鑰
創建證書籤名請求:
cat > kube-controller-manager-csr.json <
{
"CN": "system:kube-controller-manager",
"key": {
"algo": "rsa",
"size": 2048
},
"hosts": [
"127.0.0.1",
"172.16.10.101",
"172.16.10.102",
"172.16.10.103"
],
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "system:kube-controller-manager",
"OU": "testcorp"
}
]
}
EOF
hosts 列表包含所有 kube-controller-manager 節點 IP;
CN 爲 system:kube-controller-manager、O 爲 system:kube-controller-manager,kubernetes 內置的 ClusterRoleBindings system:kube-controller-manager 賦予 kube-controller-manager 工作所需的權限。
生成證書和私鑰:
cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
-ca-key=/etc/kubernetes/cert/ca-key.pem \
-config=/etc/kubernetes/cert/ca-config.json \
-profile=kubernetes kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager
將生成的證書和私鑰分發到所有 kube-controller-manager節點:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-controller-manager*.pem k8s@${node_ip}:/etc/kubernetes/cert/
done
創建和分發 kubeconfig 文件
kubeconfig 文件包含訪問 apiserver 的所有信息,如 apiserver 地址、CA 證書和自身使用的證書。
source /opt/k8s/bin/environment.sh
kubectl config set-cluster kubernetes \
--certificate-authority=/etc/kubernetes/cert/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=kube-controller-manager.kubeconfig
kubectl config set-credentials system:kube-controller-manager \
--client-certificate=kube-controller-manager.pem \
--client-key=kube-controller-manager-key.pem \
--embed-certs=true \
--kubeconfig=kube-controller-manager.kubeconfig
kubectl config set-context system:kube-controller-manager \
--cluster=kubernetes \
--user=system:kube-controller-manager \
--kubeconfig=kube-controller-manager.kubeconfig
kubectl config use-context system:kube-controller-manager --kubeconfig=kube-controller-manager.kubeconfig
分發 kubeconfig 到所有kube-controller-manager 節點:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-controller-manager.kubeconfig k8s@${node_ip}:/etc/kubernetes/
done
創建和分發 kube-controller-manager systemd unit 文件
source /opt/k8s/bin/environment.sh
cat > kube-controller-manager.service <
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
ExecStart=/opt/k8s/bin/kube-controller-manager \
--port=0 \
--secure-port=10252 \
--bind-address=127.0.0.1 \
--kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \
--service-cluster-ip-range=${SERVICE_CIDR} \
--cluster-name=kubernetes \
--cluster-signing-cert-file=/etc/kubernetes/cert/ca.pem \
--cluster-signing-key-file=/etc/kubernetes/cert/ca-key.pem \
--experimental-cluster-signing-duration=8760h \
--root-ca-file=/etc/kubernetes/cert/ca.pem \
--service-account-private-key-file=/etc/kubernetes/cert/ca-key.pem \
--leader-elect=true \
--feature-gates=RotateKubeletServerCertificate=true \
--controllers=*,bootstrapsigner,tokencleaner \
--horizontal-pod-autoscaler-use-rest-clients=true \
--horizontal-pod-autoscaler-sync-period=10s \
--tls-cert-file=/etc/kubernetes/cert/kube-controller-manager.pem \
--tls-private-key-file=/etc/kubernetes/cert/kube-controller-manager-key.pem \
--use-service-account-credentials=true \
--v=2
Restart=on
Restart=on-failure
RestartSec=5
User=k8s
[Install]
WantedBy=multi-user.target
EOF
--port=0:關閉監聽 http /metrics 的請求,同時 --address 參數無效,--bind-address 參數有效;
--secure-port=10252、--bind-address=0.0.0.0: 在所有網絡接口監聽 10252 端口的 https /metrics 請求;
--kubeconfig:指定 kubeconfig 文件路徑,kube-controller-manager 使用它連接和驗證 kube-apiserver;
--cluster-signing-*-file:簽名 TLS Bootstrap 創建的證書;
--experimental-cluster-signing-duration:指定 TLS Bootstrap 證書的有效期;
--root-ca-file:放置到容器 ServiceAccount 中的 CA 證書,用來對 kube-apiserver 的證書進行校驗;
--service-account-private-key-file:簽名 ServiceAccount 中 Token 的私鑰文件,必須和 kube-apiserver 的 --service-account-key-file 指定的公鑰文件配對使用;
--service-cluster-ip-range :指定 Service Cluster IP 網段,必須和 kube-apiserver 中的同名參數一致;
--leader-elect=true:集羣運行模式,啓用選舉功能;被選爲 leader 的節點負責處理工作,其它節點爲阻塞狀態;
--feature-gates=RotateKubeletServerCertificate=true:開啓 kublet server 證書的自動更新特性;
--controllers=*,bootstrapsigner,tokencleaner:啓用的控制器列表,tokencleaner 用於自動清理過期的 Bootstrap token;
--horizontal-pod-autoscaler-*:custom metrics 相關參數,支持 autoscaling/v2alpha1;
--tls-cert-file、--tls-private-key-file:使用 https 輸出 metrics 時使用的 Server 證書和祕鑰;
--use-service-account-credentials=true:
User=k8s:使用 k8s 賬戶運行;
kube-controller-manager 不對請求 https metrics 的 Client 證書進行校驗,故不需要指定 --tls-ca-file 參數,而且該參數已被淘汰。
分發 systemd unit 文件到所有 kube-controller-manager節點:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-controller-manager.service root@${node_ip}:/etc/systemd/system/
done
kube-controller-manager 的權限
ClusteRole: system:kube-controller-manager 的權限很小,只能創建 secret、serviceaccount 等資源對象,各 controller 的權限分散到 ClusterRole system:controller:XXX 中。
需要在 kube-controller-manager 的啓動參數中添加 --use-service-account-credentials=true 參數,這樣 main controller 會爲各 controller 創建對應的 ServiceAccount XXX-controller。
內置的 ClusterRoleBinding system:controller:XXX 將賦予各 XXX-controller ServiceAccount 對應的 ClusterRole system:controller:XXX 權限。
啓動 kube-controller-manager 服務
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-controller-manager && systemctl restart kube-controller-manager"
done
檢查服務運行狀態
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh k8s@${node_ip} "systemctl status kube-controller-manager|grep Active"
done
輸出:
172.16.10.101
Active: active (running) since Tue 2018-06-26 05:15:00 UTC; 21s ago
172.16.10.102
Active: active (running) since Tue 2018-06-26 05:15:01 UTC; 20s ago
172.16.10.103
Active: active (running) since Tue 2018-06-26 05:15:02 UTC; 20s ago
查看輸出的 metric
注意:以下命令在 kube-controller-manager 節點上執行。
kube-controller-manager 監聽 10252 端口,接收 https 請求:
[k8s@kube-node1 system]$ sudo netstat -lnpt|grep kube-controll
tcp 0 0 127.0.0.1:10252 0.0.0.0:* LISTEN 28523/kube-controll
[k8s@kube-node1 system]$ curl -s --cacert /etc/kubernetes/cert/ca.pem https://127.0.0.1:10252/metrics |head
HELP ClusterRoleAggregator_adds Total number of adds handled by workqueue: ClusterRoleAggregator
TYPE ClusterRoleAggregator_adds counter
ClusterRoleAggregator_adds 9
HELP ClusterRoleAggregator_depth Current depth of workqueue: ClusterRoleAggregator
TYPE ClusterRoleAggregator_depth gauge
ClusterRoleAggregator_depth 0
HELP ClusterRoleAggregator_queue_latency How long an item stays in workqueueClusterRoleAggregator before being requested.
TYPE ClusterRoleAggregator_queue_latency summary
ClusterRoleAggregator_queue_latency{quantile="0.5"} 304
ClusterRoleAggregator_queue_latency{quantile="0.9"} 73770
[k8s@kube-node1 system]$
注:* curl --cacert CA 證書用來驗證 kube-controller-manager https server 證書。
測試 kube-controller-manager 集羣的高可用
停掉一個或兩個節點的 kube-controller-manager 服務,觀察其它節點的日誌,看是否獲取了 leader 權限。
查看當前的 leader
[k8s@kube-server ~]$ kubectl get endpoints kube-controller-manager --namespace=kube-system -o yaml
apiVersion: v1
kind: Endpoints
metadata:
annotations:
control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"kube-node1_e213fdca-78ff-11e8-bb39-080027395360","leaseDurationSeconds":15,"acquireTime":"2018-06-26T05:15:03Z","renewTime":"2018-06-26T05:18:20Z","leaderTransitions":0}'
creationTimestamp: 2018-06-26T05:15:04Z
name: kube-controller-manager
namespace: kube-system
resourceVersion: "340"
selfLink: /api/v1/namespaces/kube-system/endpoints/kube-controller-manager
uid: e2192a53-78ff-11e8-b2bd-080027395360
可見,當前的 leader 爲 kube-node1 節點。
我們到kube-node1節點上,關掉kube-controller-manager服務,然後再觀察:
[k8s@kube-server ~]$ kubectl get endpoints kube-controller-manager --namespace=kube-system -o yaml
apiVersion: v1
kind: Endpoints
metadata:
annotations:
control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"kube-node3_e2895c01-78ff-11e8-8ff5-080027395360","leaseDurationSeconds":15,"acquireTime":"2018-06-26T05:19:38Z","renewTime":"2018-06-26T05:19:38Z","leaderTransitions":1}'
creationTimestamp: 2018-06-26T05:15:04Z
name: kube-controller-manager
namespace: kube-system
resourceVersion: "372"
selfLink: /api/v1/namespaces/kube-system/endpoints/kube-controller-manager
uid: e2192a53-78ff-11e8-b2bd-080027395360
[k8s@kube-server ~]$
可以,當前的leader已經變爲kube-node3節點了。
6.3 部署高可用 kube-scheduler 集羣
本文檔介紹部署高可用 kube-scheduler 集羣的步驟。
該集羣包含 3 個節點,kube-node1、kube-node2、kube-node3,啓動後將通過競爭選舉機制產生一個 leader 節點,其它節點爲阻塞狀態。當 leader 節點不可用後,剩餘節點將再次進行選舉產生新的 leader 節點,從而保證服務的可用性。
爲保證通信安全,本文檔先生成 x509 證書和私鑰,kube-scheduler 在如下兩種情況下使用該證書:
- 與 kube-apiserver 的安全端口通信;
- 在安全端口(https,10251) 輸出 prometheus 格式的 metrics;
創建 kube-scheduler 證書和私鑰
創建證書籤名請求:
cat > kube-scheduler-csr.json <
{
"CN": "system:kube-scheduler",
"hosts": [
"127.0.0.1",
"172.16.10.101",
"172.16.10.102",
"172.16.10.103"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "system:kube-scheduler",
"OU": "testcorp"
}
]
}
EOF
hosts 列表包含所有 kube-scheduler 節點 IP;
CN 爲 system:kube-scheduler、O 爲 system:kube-scheduler,kubernetes 內置的 ClusterRoleBindings system:kube-scheduler 將賦予 kube-scheduler 工作所需的權限。
生成證書和私鑰:
cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
-ca-key=/etc/kubernetes/cert/ca-key.pem \
-config=/etc/kubernetes/cert/ca-config.json \
-profile=kubernetes kube-scheduler-csr.json | cfssljson -bare kube-scheduler
創建和分發 kubeconfig 文件
kubeconfig 文件包含訪問 apiserver 的所有信息,如 apiserver 地址、CA 證書和自身使用的證書。
source /opt/k8s/bin/environment.sh
kubectl config set-cluster kubernetes \
--certificate-authority=/etc/kubernetes/cert/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=kube-scheduler.kubeconfig
kubectl config set-credentials system:kube-scheduler \
--client-certificate=kube-scheduler.pem \
--client-key=kube-scheduler-key.pem \
--embed-certs=true \
--kubeconfig=kube-scheduler.kubeconfig
kubectl config set-context system:kube-scheduler \
--cluster=kubernetes \
--user=system:kube-scheduler \
--kubeconfig=kube-scheduler.kubeconfig
kubectl config use-context system:kube-scheduler --kubeconfig=kube-scheduler.kubeconfig
上一步創建的證書、私鑰以及 kube-apiserver 地址被寫入到 kubeconfig 文件中。
分發 kubeconfig 到所有 kube-scheduler節點:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-scheduler.kubeconfig k8s@${node_ip}:/etc/kubernetes/
done
創建和分發 kube-scheduler systemd unit 文件
cat > kube-scheduler.service <
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
ExecStart=/opt/k8s/bin/kube-scheduler \
--address=127.0.0.1 \
--kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \
--leader-elect=true \
--v=2
Restart=on-failure
RestartSec=5
User=k8s
[Install]
WantedBy=multi-user.target
EOF
--address:在 127.0.0.1:10251 端口接收 http /metrics 請求;kube-scheduler 目前還不支持接收 https 請求;
--kubeconfig:指定 kubeconfig 文件路徑,kube-scheduler 使用它連接和驗證 kube-apiserver;
--leader-elect=true:集羣運行模式,啓用選舉功能;被選爲 leader 的節點負責處理工作,其它節點爲阻塞狀態;
User=k8s:使用 k8s 賬戶運行;
分發 systemd unit 文件到所有kube-scheduler 節點:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-scheduler.service root@${node_ip}:/etc/systemd/system/
done
啓動 kube-scheduler 服務
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-scheduler && systemctl start kube-scheduler"
done
檢查服務運行狀態
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh k8s@${node_ip} "systemctl status kube-scheduler|grep Active"
done
輸出:
172.16.10.101
Active: active (running) since Tue 2018-06-26 05:36:31 UTC; 17s ago
172.16.10.102
Active: active (running) since Tue 2018-06-26 05:36:32 UTC; 16s ago
172.16.10.103
Active: active (running) since Tue 2018-06-26 05:36:33 UTC; 16s ago
[k8s@kube-server ~]$
查看輸出的 metric
注意:以下命令在 kube-scheduler 節點上執行。
kube-scheduler 監聽 10251 端口,接收 http 請求:
[k8s@kube-node1 system]$ sudo netstat -lnpt|grep kube-sche
tcp 0 0 127.0.0.1:10251 0.0.0.0:* LISTEN 30200/kube-schedule
[k8s@kube-node1 system]$ curl -s http://127.0.0.1:10251/metrics |head
HELP apiserver_audit_event_total Counter of audit events generated and sent to the audit backend.
TYPE apiserver_audit_event_total counter
apiserver_audit_event_total 0
HELP go_gc_duration_seconds A summary of the GC invocation durations.
TYPE go_gc_duration_seconds summary
go_gc_duration_seconds{quantile="0"} 1.1776e-05
go_gc_duration_seconds{quantile="0.25"} 1.2644e-05
go_gc_duration_seconds{quantile="0.5"} 1.7374e-05
go_gc_duration_seconds{quantile="0.75"} 2.2085e-05
go_gc_duration_seconds{quantile="1"} 4.5083e-05
[k8s@kube-node1 system]$
測試 kube-scheduler 集羣的高可用
隨便找一個或兩個 master 節點,停掉 kube-scheduler 服務,看其它節點是否獲取了 leader 權限(systemd 日誌)。
查看當前的 leader
[k8s@kube-node1 system]$ kubectl get endpoints kube-scheduler --namespace=kube-system -o yaml
apiVersion: v1
kind: Endpoints
metadata:
annotations:
control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"kube-node1_e1d9a10f-7902-11e8-814d-080027395360","leaseDurationSeconds":15,"acquireTime":"2018-06-26T05:36:33Z","renewTime":"2018-06-26T05:38:42Z","leaderTransitions":0}'
creationTimestamp: 2018-06-26T05:36:33Z
name: kube-scheduler
namespace: kube-system
resourceVersion: "1008"
selfLink: /api/v1/namespaces/kube-system/endpoints/kube-scheduler
uid: e2769a5d-7902-11e8-b2bd-080027395360
可見,當前的 leader 爲 kube-node1 節點。
7、部署node節點
kubernetes node節點運行如下組件:
docker
kubelet
kube-proxy
7.1 部署docker組件
kubelet 通過 Container Runtime Interface (CRI) 與 docker 進行交互。
下載和分發 docker 二進制文件
到 https://download.docker.com/linux/static/stable/x86_64/ 頁面下載最新發布包:
wget https://download.docker.com/linux/static/stable/x86_64/docker-18.03.1-ce.tgz
tar -xvf docker-18.03.1-ce.tgz
分發二進制文件到所有 worker 節點:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp docker/docker* k8s@${node_ip}:/opt/k8s/bin/
ssh k8s@${node_ip} "chmod +x /opt/k8s/bin/*"
done
創建和分發 systemd unit 文件
cat > docker.service <<"EOF"
[Unit]
Description=Docker Application Container Engine
Documentation=http://docs.docker.io
[Service]
Environment="PATH=/opt/k8s/bin:/bin:/sbin:/usr/bin:/usr/sbin"
EnvironmentFile=-/run/flannel/docker
ExecStart=/opt/k8s/bin/dockerd --log-level=error $DOCKER_NETWORK_OPTIONS
ExecReload=/bin/kill -s HUP $MAINPID
Restart=on-failure
RestartSec=5
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
Delegate=yes
KillMode=process
[Install]
WantedBy=multi-user.target
EOF
EOF 前後有引號,這樣 bash 不會替換文檔中的變量,如 $DOCKER_NETWORK_OPTIONS;
dockerd 運行時會調用其它 docker 命令,如 docker-proxy,所以需要將 docker 命令所在的目錄加到 PATH 環境變量中;
flanneld 啓動時將網絡配置寫入到 /run/flannel/docker 文件中的變量 DOCKER_NETWORK_OPTIONS,dockerd 命令行上指定該變量值來設置docker0 網橋參數;
如果指定了多個 EnvironmentFile 選項,則必須將 /run/flannel/docker 放在最後(確保 docker0 使用 flanneld 生成的 bip 參數);
docker 需要以 root 用於運行;
docker 從 1.13 版本開始,可能將 iptables FORWARD chain的默認策略設置爲DROP,從而導致 ping 其它 Node 上的 Pod IP 失敗,遇到這種情況時,需要手動設置策略爲 ACCEPT:
分發 systemd unit 文件到所有 worker 機器:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp docker.service root@${node_ip}:/etc/systemd/system/
done
啓動 docker 服務
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl stop firewalld && systemctl disable firewalld"
ssh root@${node_ip} "iptables -F && iptables -X && iptables -F -t nat && iptables -X -t nat"
ssh root@${node_ip} "iptables -P FORWARD ACCEPT"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable docker && systemctl start docker"
done
關閉 firewalld(centos7)/ufw(ubuntu16.04),否則可能會重複創建 iptables 規則;
清理舊的 iptables rules 和 chains 規則;
檢查服務運行狀態
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh k8s@${node_ip} "systemctl status docker|grep Active"
done
檢查 docker0 網橋
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh k8s@${node_ip} "/usr/sbin/ip addr show"
done
確認各 work 節點的 docker0 網橋和 flannel.1 接口的 IP 處於同一個網段中(如下 172.30.49.0 和 172.30.49.1):
[k8s@kube-node1 system]$ ip a
1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp0s3: mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 08:00:27:39:53:60 brd ff:ff:ff:ff:ff:ff
inet 10.0.2.15/24 brd 10.0.2.255 scope global noprefixroute dynamic enp0s3
valid_lft 69101sec preferred_lft 69101sec
inet6 fe80::953e:9248:d505:388f/64 scope link noprefixroute
valid_lft forever preferred_lft forever
3: enp0s8: mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 08:00:27:e5:7e:fd brd ff:ff:ff:ff:ff:ff
inet 172.16.10.101/24 brd 172.16.10.255 scope global noprefixroute enp0s8
valid_lft forever preferred_lft forever
inet6 fe80::a00:27ff:fee5:7efd/64 scope link
valid_lft forever preferred_lft forever
4: flannel.1: mtu 1450 qdisc noqueue state UNKNOWN group default
link/ether e6:1a:e1:53:92:ef brd ff:ff:ff:ff:ff:ff
inet 172.30.49.0/32 scope global flannel.1
valid_lft forever preferred_lft forever
inet6 fe80::e41a:e1ff:fe53:92ef/64 scope link
valid_lft forever preferred_lft forever
5: docker0: mtu 1500 qdisc noqueue state DOWN group default
link/ether 02:42:3f:5a:25:80 brd ff:ff:ff:ff:ff:ff
inet 172.30.49.1/24 brd 172.30.49.255 scope global docker0
valid_lft forever preferred_lft forever
[k8s@kube-node1 system]$
7.2 部署 kubelet 組件
kublet 運行在每個 worker 節點上,接收 kube-apiserver 發送的請求,管理 Pod 容器,執行交互式命令如 exec、run、logs 等。
kublet 啓動時自動向 kube-apiserver 註冊節點信息,內置的 cadvisor 統計和監控節點的資源使用情況。
爲確保安全,本文檔只開啓接收 https 請求的安全端口,對請求進行認證和授權,拒絕未授權的訪問(如 apiserver、heapster)。
下載最新版本的二進制文件
從 CHANGELOG頁面 下載 server tarball 文件。
wget https://dl.k8s.io/v1.10.4/kubernetes-server-linux-amd64.tar.gz
tar -xzvf kubernetes-server-linux-amd64.tar.gz
將二進制文件拷貝到所有 node 節點:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp server/bin/* k8s@${node_ip}:/opt/k8s/bin/
ssh k8s@${node_ip} "chmod +x /opt/k8s/bin/*"
done
創建 kubelet bootstrap kubeconfig 文件
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_name}"
創建 token
export BOOTSTRAP_TOKEN=$(kubeadm token create \
--description kubelet-bootstrap-token \
--groups system:bootstrappers:${node_name} \
--kubeconfig ~/.kube/config)
設置集羣參數
kubectl config set-cluster kubernetes \
--certificate-authority=/etc/kubernetes/cert/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig
設置客戶端認證參數
kubectl config set-credentials kubelet-bootstrap \
--token=${BOOTSTRAP_TOKEN} \
--kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig
設置上下文參數
kubectl config set-context default \
--cluster=kubernetes \
--user=kubelet-bootstrap \
--kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig
設置默認上下文
kubectl config use-context default --kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig
done
證書中寫入 Token 而非證書,證書後續由 controller-manager 創建。
查看 kubeadm 爲各節點創建的 token:
[k8s@kube-server ~]$ kubeadm token list --kubeconfig ~/.kube/config
TOKEN TTL EXPIRES USAGES DESCRIPTION EXTRA GROUPS
34jnny.c7ks4atqkqpclbe1 23h 2018-06-28T01:32:46Z authentication,signing kubelet-bootstrap-token system:bootstrappers:kube-node2
jlzg9x.la6w75ab1jf9dsg2 23h 2018-06-28T01:32:45Z authentication,signing kubelet-bootstrap-token system:bootstrappers:kube-node1
qgfb6a.8w0fm4i8kwh8y5gd 23h 2018-06-28T01:32:46Z authentication,signing kubelet-bootstrap-token system:bootstrappers:kube-node3
分發 bootstrap kubeconfig 文件到所有 node節點
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_ip}"
scp kubelet-bootstrap-${node_name}.kubeconfig k8s@${node_name}:/etc/kubernetes/kubelet-bootstrap.kubeconfig
done
創建和分發 kubelet 參數配置文件
從 v1.10 開始,kubelet 部分參數需在配置文件中配置,kubelet --help 會提示:
[k8s@kube-server ~]$ kubelet --help|grep DEPRECATED
--address 0.0.0.0 The IP address for the Kubelet to serve on (set to 0.0.0.0 for all IPv4 interfaces and ::
for all IPv6 interfaces) (default 0.0.0.0) (DEPRECATED: This parameter should be set via the config file specified by the Kubelet's --config flag. See https://kubernetes.io/docs/tasks/administer-cluster/kubelet-config-file/ for more information.)
創建 kubelet 參數配置模板文件:
source /opt/k8s/bin/environment.sh
cat > kubelet.config.json.template <
{
"kind": "KubeletConfiguration",
"apiVersion": "kubelet.config.k8s.io/v1beta1",
"authentication": {
"x509": {
"clientCAFile": "/etc/kubernetes/cert/ca.pem"
},
"webhook": {
"enabled": true,
"cacheTTL": "2m0s"
},
"anonymous": {
"enabled": false
}
},
"authorization": {
"mode": "Webhook",
"webhook": {
"cacheAuthorizedTTL": "5m0s",
"cacheUnauthorizedTTL": "30s"
}
},
"address": "##NODE_IP##",
"port": 10250,
"readOnlyPort": 0,
"cgroupDriver": "cgroupfs",
"hairpinMode": "promiscuous-bridge",
"serializeImagePulls": false,
"featureGates": {
"RotateKubeletClientCertificate": true,
"RotateKubeletServerCertificate": true
},
"clusterDomain": "cluster.local.",
"clusterDNS": ["10.254.0.2"]
}
EOF
address:API 監聽地址,不能爲 127.0.0.1,否則 kube-apiserver、heapster 等不能調用 kubelet 的 API;
readOnlyPort=0:關閉只讀端口(默認 10255),等效爲未指定;
authentication.anonymous.enabled:設置爲 false,不允許匿名訪問 10250 端口;
authentication.x509.clientCAFile:指定簽名客戶端證書的 CA 證書,開啓 HTTP 證書認證;
authentication.webhook.enabled=true:開啓 HTTPs bearer token 認證;
對於未通過 x509 證書和 webhook 認證的請求(kube-apiserver 或其他客戶端),將被拒絕,提示 Unauthorized;
authroization.mode=Webhook:kubelet 使用 SubjectAccessReview API 查詢 kube-apiserver 某 user、group 是否具有操作資源的權限(RBAC);
featureGates.RotateKubeletClientCertificate、featureGates.RotateKubeletServerCertificate:自動 rotate 證書,證書的有效期取決於 kube-controller-manager 的 --experimental-cluster-signing-duration 參數;
需要 root 賬戶運行;
爲各節點創建和分發 kubelet 配置文件:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
sed -e "s/##NODE_IP##/${node_ip}/" kubelet.config.json.template > kubelet.config-${node_ip}.json
scp kubelet.config-${node_ip}.json root@${node_ip}:/etc/kubernetes/kubelet.config.json
done
創建和分發 kubelet systemd unit 文件
創建 kubelet systemd unit 文件模板:
cat > kubelet.service.template <
[Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=docker.service
Requires=docker.service
[Service]
WorkingDirectory=/var/lib/kubelet
ExecStart=/opt/k8s/bin/kubelet \
--bootstrap-kubeconfig=/etc/kubernetes/kubelet-bootstrap.kubeconfig \
--cert-dir=/etc/kubernetes/cert \
--kubeconfig=/etc/kubernetes/kubelet.kubeconfig \
--config=/etc/kubernetes/kubelet.config.json \
--hostname-override=##NODE_NAME## \
--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest \
--logtostderr=true \
--v=2
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
EOF
如果設置了 --hostname-override 選項,則 kube-proxy 也需要設置該選項,否則會出現找不到 Node 的情況;
--bootstrap-kubeconfig:指向 bootstrap kubeconfig 文件,kubelet 使用該文件中的用戶名和 token 向 kube-apiserver 發送 TLS Bootstrapping 請求;
K8S approve kubelet 的 csr 請求後,在 --cert-dir 目錄創建證書和私鑰文件,然後寫入 --kubeconfig 文件;
--feature-gates:啓用 kuelet 證書輪轉功能;
爲各節點創建和分發 kubelet systemd unit 文件:
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_name}"
sed -e "s/##NODE_NAME##/${node_name}/" kubelet.service.template > kubelet-${node_name}.service
scp kubelet-${node_name}.service root@${node_name}:/etc/systemd/system/kubelet.service
done
Bootstrap Token Auth 和授予權限
kublet 啓動時查找配置的 --kubeletconfig 文件是否存在,如果不存在則使用 --bootstrap-kubeconfig 向 kube-apiserver 發送證書籤名請求 (CSR)。
kube-apiserver 收到 CSR 請求後,對其中的 Token 進行認證(事先使用 kubeadm 創建的 token),認證通過後將請求的 user 設置爲 system:bootstrap:,group 設置爲 system:bootstrappers,這一過程稱爲 Bootstrap Token Auth。
默認情況下,這個 user 和 group 沒有創建 CSR 的權限,kubelet 啓動失敗,錯誤日誌如下:
$ sudo journalctl -u kubelet -a |grep -A 2 'certificatesigningrequests'
May 06 06:42:36 kube-node1 kubelet[26986]: F0506 06:42:36.314378 26986 server.go:233] failed to run Kubelet: cannot create certificate signing request: certificatesigningrequests.certificates.k8s.io is forbidden: User "system:bootstrap:lemy40" cannot create certificatesigningrequests.certificates.k8s.io at the cluster scope
May 06 06:42:36 kube-node1 systemd[1]: kubelet.service: Main process exited, code=exited, status=255/n/a
May 06 06:42:36 kube-node1 systemd[1]: kubelet.service: Failed with result 'exit-code'.
解決辦法是:創建一個 clusterrolebinding,將 group system:bootstrappers 和 clusterrole system:node-bootstrapper 綁定:
$ kubectl create clusterrolebinding kubelet-bootstrap --clusterrole=system:node-bootstrapper --group=system:bootstrappers
啓動 kubelet 服務
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p /var/lib/kubelet" # 必須先創建工作目錄
ssh root@${node_ip} "swapoff -a" # 關閉 swap 分區
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kubelet && systemctl restart kubelet"
done
kubelet 啓動後使用 --bootstrap-kubeconfig 向 kube-apiserver 發送 CSR 請求,當這個 CSR 被 approve 後,kube-controller-manager 爲 kubelet 創建 TLS 客戶端證書、私鑰和 --kubeletconfig 文件。
注意:kube-controller-manager 需要配置 --cluster-signing-cert-file 和 --cluster-signing-key-file 參數,纔會爲 TLS Bootstrap 創建證書和私鑰。
[k8s@kube-server ~]$ kubectl get csr
NAME AGE REQUESTOR CONDITION
node-csr-9UuHCTss6Mxs4FTcuNqU9sBe6FC1of_Da7t8luoVL_0 2m system:bootstrap:jlzg9x Pending
node-csr-9WiUTwjqsFmNLiV3wqKYRY_MCy-V6lxNauLHJuuUxpc 2m system:bootstrap:34jnny Pending
node-csr-j0SQAP6ODUDrP0QQUto0yfCc41Kp_yMYhXYLS3IluCY 2m system:bootstrap:qgfb6a Pending
[k8s@kube-server ~]$ kubectl get nodes
No resources found.
[k8s@kube-server ~]$
三個 node節點的 csr 均處於 pending 狀態。
approve kubelet CSR 請求
可以手動或自動 approve CSR 請求。推薦使用自動的方式,因爲從 v1.8 版本開始,可以自動輪轉approve csr 後生成的證書。
手動 approve CSR 請求
[k8s@kube-server ~]$ kubectl certificate approve node-csr-9UuHCTss6Mxs4FTcuNqU9sBe6FC1of_Da7t8luoVL_0
certificatesigningrequest.certificates.k8s.io "node-csr-9UuHCTss6Mxs4FTcuNqU9sBe6FC1of_Da7t8luoVL_0" approved
[k8s@kube-server ~]$ kubectl describe csr node-csr-9UuHCTss6Mxs4FTcuNqU9sBe6FC1of_Da7t8luoVL_0
Name: node-csr-9UuHCTss6Mxs4FTcuNqU9sBe6FC1of_Da7t8luoVL_0
Labels:
Annotations:
CreationTimestamp: Wed, 27 Jun 2018 04:44:59 +0000
Requesting User: system:bootstrap:jlzg9x
Status: Approved,Issued
Subject:
Common Name: system:node:kube-node1
Serial Number:
Organization: system:nodes
Events:
Requesting User:請求 CSR 的用戶,kube-apiserver 對它進行認證和授權;
Subject:請求籤名的證書信息;
證書的 CN 是 system:node:kube-node2, Organization 是 system:nodes,kube-apiserver 的 Node 授權模式會授予該證書的相關權限;
自動 approve CSR 請求
創建三個 ClusterRoleBinding,分別用於自動 approve client、renew client、renew server 證書:
cat > csr-crb.yaml <
Approve all CSRs for the group "system:bootstrappers"
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: auto-approve-csrs-for-group
subjects:
- kind: Group
name: system:bootstrappers
apiGroup: rbac.authorization.k8s.io
roleRef:
kind: ClusterRole
name: system:certificates.k8s.io:certificatesigningrequests:nodeclient
apiGroup: rbac.authorization.k8s.io
To let a node of the group "system:bootstrappers" renew its own credentials
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: node-client-cert-renewal
subjects:
- kind: Group
name: system:bootstrappers
apiGroup: rbac.authorization.k8s.io
roleRef:
kind: ClusterRole
name: system:certificates.k8s.io:certificatesigningrequests:selfnodeclient
apiGroup: rbac.authorization.k8s.io
A ClusterRole which instructs the CSR approver to approve a node requesting a
serving cert matching its client cert.
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: approve-node-server-renewal-csr
rules:
- apiGroups: ["certificates.k8s.io"]
resources: ["certificatesigningrequests/selfnodeserver"]
verbs: ["create"]
To let a node of the group "system:nodes" renew its own server credentials
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: node-server-cert-renewal
subjects:
- kind: Group
name: system:nodes
apiGroup: rbac.authorization.k8s.io
roleRef:
kind: ClusterRole
name: approve-node-server-renewal-csr
apiGroup: rbac.authorization.k8s.io
EOF
生效配置:
[k8s@kube-server ~]$ kubectl apply -f csr-crb.yaml
clusterrolebinding.rbac.authorization.k8s.io "auto-approve-csrs-for-group" created
clusterrolebinding.rbac.authorization.k8s.io "node-client-cert-renewal" created
clusterrole.rbac.authorization.k8s.io "approve-node-server-renewal-csr" created
clusterrolebinding.rbac.authorization.k8s.io "node-server-cert-renewal" created
查看 kublet 的情況
等待一段時間(1-10 分鐘),三個節點的 CSR 都被自動 approve:
[k8s@kube-server ~]$ kubectl get csr
NAME AGE REQUESTOR CONDITION
csr-72dq4 5m system:node:kube-node1 Pending
node-csr-9UuHCTss6Mxs4FTcuNqU9sBe6FC1of_Da7t8luoVL_0 10m system:bootstrap:jlzg9x Approved,Issued
node-csr-9WiUTwjqsFmNLiV3wqKYRY_MCy-V6lxNauLHJuuUxpc 10m system:bootstrap:34jnny Pending
node-csr-j0SQAP6ODUDrP0QQUto0yfCc41Kp_yMYhXYLS3IluCY 10m system:bootstrap:qgfb6a Pending
[k8s@kube-server ~]$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
kube-node1 Ready 5m v1.10.4
[k8s@kube-server ~]$ kubectl get csr
NAME AGE REQUESTOR CONDITION
csr-72dq4 23m system:node:kube-node1 Approved,Issued
csr-wnkj8 14m system:node:kube-node2 Approved,Issued
csr-zxkbr 14m system:node:kube-node3 Approved,Issued
node-csr-9UuHCTss6Mxs4FTcuNqU9sBe6FC1of_Da7t8luoVL_0 27m system:bootstrap:jlzg9x Approved,Issued
node-csr-9WiUTwjqsFmNLiV3wqKYRY_MCy-V6lxNauLHJuuUxpc 27m system:bootstrap:34jnny Approved,Issued
node-csr-j0SQAP6ODUDrP0QQUto0yfCc41Kp_yMYhXYLS3IluCY 27m system:bootstrap:qgfb6a Approved,Issued
[k8s@kube-server ~]$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
kube-node1 Ready 23m v1.10.4
kube-node2 Ready 14m v1.10.4
kube-node3 Ready 14m v1.10.4
[k8s@kube-server ~]$
kube-controller-manager 爲各 node 生成了 kubeconfig 文件和公私鑰:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "ls -l /etc/kubernetes/kubelet.kubeconfig"
ssh root@${node_ip} "ls -l /etc/kubernetes/cert/|grep kubelet"
done
輸出:
172.16.10.101
-rw-------. 1 root root 2290 Jun 27 04:49 /etc/kubernetes/kubelet.kubeconfig
-rw-r--r--. 1 root root 1046 Jun 27 04:49 kubelet-client.crt
-rw-------. 1 root root 227 Jun 27 04:44 kubelet-client.key
-rw-------. 1 root root 1330 Jun 27 04:56 kubelet-server-2018-06-27-04-56-32.pem
- 1 root root 59 Jun 27 04:56 kubelet-server-current.pem -> /etc/kubernetes/cert/kubelet-server-2018-06-27-04-56-32.pem
172.16.10.102
-rw-------. 1 root root 2290 Jun 27 04:58 /etc/kubernetes/kubelet.kubeconfig
-rw-r--r--. 1 root root 1046 Jun 27 04:58 kubelet-client.crt
-rw-------. 1 root root 227 Jun 27 04:45 kubelet-client.key
-rw-------. 1 root root 1330 Jun 27 04:58 kubelet-server-2018-06-27-04-58-41.pem
- 1 root root 59 Jun 27 04:58 kubelet-server-current.pem -> /etc/kubernetes/cert/kubelet-server-2018-06-27-04-58-41.pem
172.16.10.103
-rw-------. 1 root root 2290 Jun 27 04:58 /etc/kubernetes/kubelet.kubeconfig
-rw-r--r--. 1 root root 1046 Jun 27 04:58 kubelet-client.crt
-rw-------. 1 root root 227 Jun 27 04:45 kubelet-client.key
-rw-------. 1 root root 1330 Jun 27 04:58 kubelet-server-2018-06-27-04-58-42.pem
- 1 root root 59 Jun 27 04:58 kubelet-server-current.pem -> /etc/kubernetes/cert/kubelet-server-2018-06-27-04-58-42.pem
kubelet-server 證書會週期輪轉。
kubelet 提供的 API 接口
kublet 啓動後監聽多個端口,用於接收 kube-apiserver 或其它組件發送的請求:
[k8s@kube-node1 ~]$ sudo netstat -lnpt|grep kubelet
tcp 0 0 172.16.10.101:4194 0.0.0.0:* LISTEN 9191/kubelet
tcp 0 0 127.0.0.1:10248 0.0.0.0:* LISTEN 9191/kubelet
tcp 0 0 172.16.10.101:10250 0.0.0.0:* LISTEN 9191/kubelet
4194: cadvisor http 服務;
10248: healthz http 服務;
10250: https API 服務;注意:未開啓只讀端口 10255;
例如執行 kubectl ec -it nginx-ds-5rmws -- sh 命令時,kube-apiserver 會向 kubelet 發送如下請求:
POST /exec/default/nginx-ds-5rmws/my-nginx?command=sh&input=1&output=1&tty=1
kubelet 接收 10250 端口的 https 請求:
/pods、/runningpods
/metrics、/metrics/cadvisor、/metrics/probes
/spec
/stats、/stats/container
/logs
/run/、"/exec/", "/attach/", "/portForward/", "/containerLogs/" 等管理;
詳情參考:
https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/server/server.go#L434:3
由於關閉了匿名認證,同時開啓了 webhook 授權,所有訪問 10250 端口 https API 的請求都需要被認證和授權。
預定義的 ClusterRole system:kubelet-api-admin 授予訪問 kubelet 所有 API 的權限:
[k8s@kube-server ~]$ kubectl describe clusterrole system:kubelet-api-admin
Name: system:kubelet-api-admin
Labels: kubernetes.io/bootstrapping=rbac-defaults
Annotations: rbac.authorization.kubernetes.io/autoupdate=true
PolicyRule:
Resources Non-Resource URLs Resource Names Verbs
--------- ----------------- -------------- -----
nodes [] [] [get list watch proxy]
nodes/log [] [] [*]
nodes/metrics [] [] [*]
nodes/proxy [] [] [*]
nodes/spec [] [] [*]
nodes/stats [] [] [*]
kublet api 認證和授權
kublet 配置瞭如下認證參數:
authentication.anonymous.enabled:設置爲 false,不允許匿名訪問 10250 端口;
authentication.x509.clientCAFile:指定簽名客戶端證書的 CA 證書,開啓 HTTPs 證書認證;
authentication.webhook.enabled=true:開啓 HTTPs bearer token 認證;
同時配置瞭如下授權參數:
authroization.mode=Webhook:開啓 RBAC 授權;
kubelet 收到請求後,使用 clientCAFile 對證書籤名進行認證,或者查詢 bearer token 是否有效。如果兩者都沒通過,則拒絕請求,提示 Unauthorized:
[k8s@kube-server ~]$ curl -s --cacert /etc/kubernetes/cert/ca.pem https://172.16.10.101:10250/metrics
Unauthorized
[k8s@kube-server ~]$
[k8s@kube-server ~]$ curl -s --cacert /etc/kubernetes/cert/ca.pem -H "Authorization: Bearer 123456" https://172.16.10.101:10250/metrics
Unauthorized
[k8s@kube-server ~]$
通過認證後,kubelet 使用 SubjectAccessReview API 向 kube-apiserver 發送請求,查詢證書或 token 對應的 user、group 是否有操作資源的權限(RBAC);
證書認證和授權:
權限不足的證書;
[k8s@kube-node1 ~]$ curl -s --cacert /etc/kubernetes/cert/ca.pem --cert /etc/kubernetes/cert/kube-controller-manager.pem --key /etc/kubernetes/cert/kube-controller-manager-key.pem https://172.16.10.101:10250/metrics
Forbidden (user=system:kube-controller-manager, verb=get, resource=nodes, subresource=metrics)
[k8s@kube-node1 ~]$
使用部署 kubectl 命令行工具時創建的、具有最高權限的 admin 證書;
$ curl -s --cacert /etc/kubernetes/cert/ca.pem --cert /opt/k8s/admin.pem --key /opt/k8s/admin-key.pem https://172.16.10.101:10250/metrics|head
注:如果未使用絕對路徑指出admin密鑰位置,會找不到。
bear token 認證和授權:
創建一個 ServiceAccount,將它和 ClusterRole system:kubelet-api-admin 綁定,從而具有調用 kubelet API 的權限:
kubectl create sa kubelet-api-test
kubectl create clusterrolebinding kubelet-api-test --clusterrole=system:kubelet-api-admin --serviceaccount=default:kubelet-api-test
SECRET=$(kubectl get secrets | grep kubelet-api-test | awk '{print $1}')
TOKEN=$(kubectl describe secret ${SECRET} | grep -E '^token' | awk '{print $2}')
echo ${TOKEN}
[k8s@kube-server ~]$ echo ${TOKEN}
eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.isa6PPJtg0WEstKwuozjT-CHs6EEonq12mpGqCk4SIaPe2TWjPDDHiczRf9Yt4ivmOakquhiYBs9vnDuPuINXWHNCzEudYMDz2mIYHwXH0s26CT-eSxXCnPRH54H9zVjJzNSZ9LhYgLLxOPSFldNaLd8E0MCCjGwBWqucSAraxHNyNmVALbi8LKaPt6u3JiHV02cGhqhG7xEiS5oeSdXh8kWSxd1wOtGc7bmQerrVDNnTqPNflb926zRGuPrELghdm0SeFVWtFGTjILvpgPugq3biLRt199ct8afaIqqH9tuDlpd32Cv4IVPKvvnIutamOILnb04FfrkzwPb6iv4xw
[k8s@kube-server ~]$ curl -s --cacert /etc/kubernetes/cert/ca.pem -H "Authorization: Bearer ${TOKEN}" https://172.16.10.101:10250/metrics|head
HELP apiserver_client_certificate_expiration_seconds Distribution of the remaining lifetime on the certificate used to authenticate a request.
TYPE apiserver_client_certificate_expiration_seconds histogram
apiserver_client_certificate_expiration_seconds_bucket{le="0"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="21600"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="43200"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="86400"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="172800"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="345600"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="604800"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="2.592e+06"} 0
cadvisor 和 metrics
cadvisor 統計所在節點各容器的資源(CPU、內存、磁盤、網卡)使用情況,分別在自己的 http web 頁面(4194 端口)和 10250 以 promehteus metrics 的形式輸出。
瀏覽器訪問 http://172.16.10.101:4194/containers/ 可以查看到 cadvisor 的監控頁面:
因爲我們是使用的Virtualbox虛機搭建的測試環境,所以需要配置個轉發端口,便於我們從外部訪問到測試環境中kube-node1中的服務。
配置方法如下所示。
獲取 kublet 的配置
從 kube-apiserver 獲取各 node 的配置:
[k8s@kube-server ~]$ curl -sSL --cacert /etc/kubernetes/cert/ca.pem --cert /home/k8s/admin.pem --key /home/k8s/admin-key.pem https://${MASTER_IP}:6443/api/v1/nodes/kube-node1/proxy/configz | jq '.kubeletconfig|.kind="KubeletConfiguration"|.apiVersion="kubelet.config.k8s.io/v1beta1"'
{
"syncFrequency": "1m0s",
"fileCheckFrequency": "20s",
"httpCheckFrequency": "20s",
"address": "172.16.10.101",
"port": 10250,
"authentication": {
"x509": {
"clientCAFile": "/etc/kubernetes/cert/ca.pem"
},
"webhook": {
"enabled": true,
"cacheTTL": "2m0s"
},
"anonymous": {
"enabled": false
}
},
"authorization": {
"mode": "Webhook",
"webhook": {
"cacheAuthorizedTTL": "5m0s",
"cacheUnauthorizedTTL": "30s"
}
},
"registryPullQPS": 5,
"registryBurst": 10,
"eventRecordQPS": 5,
"eventBurst": 10,
"enableDebuggingHandlers": true,
"healthzPort": 10248,
"healthzBindAddress": "127.0.0.1",
"oomScoreAdj": -999,
"clusterDomain": "cluster.local.",
"clusterDNS": [
"10.254.0.2"
],
"streamingConnectionIdleTimeout": "4h0m0s",
"nodeStatusUpdateFrequency": "10s",
"imageMinimumGCAge": "2m0s",
"imageGCHighThresholdPercent": 85,
"imageGCLowThresholdPercent": 80,
"volumeStatsAggPeriod": "1m0s",
"cgroupsPerQOS": true,
"cgroupDriver": "cgroupfs",
"cpuManagerPolicy": "none",
"cpuManagerReconcilePeriod": "10s",
"runtimeRequestTimeout": "2m0s",
"hairpinMode": "promiscuous-bridge",
"maxPods": 110,
"podPidsLimit": -1,
"resolvConf": "/etc/resolv.conf",
"cpuCFSQuota": true,
"maxOpenFiles": 1000000,
"contentType": "application/vnd.kubernetes.protobuf",
"kubeAPIQPS": 5,
"kubeAPIBurst": 10,
"serializeImagePulls": false,
"evictionHard": {
"imagefs.available": "15%",
"memory.available": "100Mi",
"nodefs.available": "10%",
"nodefs.inodesFree": "5%"
},
"evictionPressureTransitionPeriod": "5m0s",
"enableControllerAttachDetach": true,
"makeIPTablesUtilChains": true,
"iptablesMasqueradeBit": 14,
"iptablesDropBit": 15,
"featureGates": {
"RotateKubeletClientCertificate": true,
"RotateKubeletServerCertificate": true
},
"failSwapOn": true,
"containerLogMaxSize": "10Mi",
"containerLogMaxFiles": 5,
"enforceNodeAllocatable": [
"pods"
],
"kind": "KubeletConfiguration",
"apiVersion": "kubelet.config.k8s.io/v1beta1"
}
[k8s@kube-server ~]$
7.3 部署 kube-proxy 組件
創建 kube-proxy 證書
創建證書籤名請求:
cat > kube-proxy-csr.json <
{
"CN": "system:kube-proxy",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "testcorp"
}
]
}
EOF
CN:指定該證書的 User 爲 system:kube-proxy;
預定義的 RoleBinding system:node-proxier 將User system:kube-proxy 與 Role system:node-proxier 綁定,該 Role 授予了調用 kube-apiserver Proxy 相關 API 的權限;
該證書只會被 kube-proxy 當做 client 證書使用,所以 hosts 字段爲空;
生成證書和私鑰:
cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
-ca-key=/etc/kubernetes/cert/ca-key.pem \
-config=/etc/kubernetes/cert/ca-config.json \
-profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy
創建和分發 kubeconfig 文件
source /opt/k8s/bin/environment.sh
設置集羣參數
kubectl config set-cluster kubernetes \
--certificate-authority=/etc/kubernetes/cert/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=kube-proxy.kubeconfig
設置客戶端認證參數
kubectl config set-credentials kube-proxy \
--client-certificate=kube-proxy.pem \
--client-key=kube-proxy-key.pem \
--embed-certs=true \
--kubeconfig=kube-proxy.kubeconfig
設置上下文參數
kubectl config set-context default \
--cluster=kubernetes \
--user=kube-proxy \
--kubeconfig=kube-proxy.kubeconfig
設置默認上下文
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
--embed-certs=true:將 ca.pem 和 admin.pem 證書內容嵌入到生成的 kubectl-proxy.kubeconfig 文件中(不加時,寫入的是證書文件路徑);
分發 kubeconfig 文件:
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_name}"
scp kube-proxy.kubeconfig k8s@${node_name}:/etc/kubernetes/
done
創建 kube-proxy 配置文件
從 v1.10 開始,kube-proxy 部分參數可以配置文件中配置。可以使用 --write-config-to 選項生成該配置文件,或者參考 kubeproxyconfig 的類型定義源文件 :https://github.com/kubernetes/kubernetes/blob/master/pkg/proxy/apis/kubeproxyconfig/types.go
創建 kube-proxy config 文件模板:
cat >kube-proxy.config.yaml.template <
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: ##NODE_IP##
clientConnection:
kubeconfig: /etc/kubernetes/kube-proxy.kubeconfig
clusterCIDR: 172.30.0.0/16
healthzBindAddress: ##NODE_IP##:10256
hostnameOverride: ##NODE_NAME##
kind: KubeProxyConfiguration
metricsBindAddress: ##NODE_IP##:10249
mode: "ipvs"
EOF
bindAddress: 監聽地址;
clientConnection.kubeconfig: 連接 apiserver 的 kubeconfig 文件;
clusterCIDR: 必須與 kube-controller-manager 的 --cluster-cidr 選項值一致;kube-proxy 根據 --cluster-cidr 判斷集羣內部和外部流量,指定 --cluster-cidr 或 --masquerade-all 選項後 kube-proxy 纔會對訪問 Service IP 的請求做 SNAT;
hostnameOverride: 參數值必須與 kubelet 的值一致,否則 kube-proxy 啓動後會找不到該 Node,從而不會創建任何 ipvs 規則;
mode: 使用 ipvs 模式;
爲各節點創建和分發 kube-proxy 配置文件:
source /opt/k8s/bin/environment.sh
for (( i=0; i < 3; i++ ))
do
echo ">>> ${NODE_NAMES[i]}"
sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-proxy.config.yaml.template > kube-proxy-${NODE_NAMES[i]}.config.yaml
scp kube-proxy-${NODE_NAMES[i]}.config.yaml root@${NODE_NAMES[i]}:/etc/kubernetes/kube-proxy.config.yaml
done
創建和分發 kube-proxy systemd unit 文件
source /opt/k8s/bin/environment.sh
cat > kube-proxy.service <
[Unit]
Description=Kubernetes Kube-Proxy Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
[Service]
WorkingDirectory=/var/lib/kube-proxy
ExecStart=/opt/k8s/bin/kube-proxy \
--config=/etc/kubernetes/kube-proxy.config.yaml \
--logtostderr=true \
--v=2
Restart=on-failure
RestartSec=5
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
分發 kube-proxy systemd unit 文件:
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_name}"
scp kube-proxy.service root@${node_name}:/etc/systemd/system/
done
啓動 kube-proxy 服務
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p /var/lib/kube-proxy" # 必須先創建工作目錄
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-proxy && systemctl start kube-proxy"
done
檢查啓動結果
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh k8s@${node_ip} "systemctl status kube-proxy|grep Active"
done
確保狀態爲 active (running)
查看監聽端口和 metrics
[k8s@kube-node1 cert]$ sudo netstat -lnpt|grep kube-prox
tcp 0 0 172.16.10.101:10249 0.0.0.0:* LISTEN 17534/kube-proxy
tcp 0 0 172.16.10.101:10256 0.0.0.0:* LISTEN 17534/kube-proxy
10249:http prometheus metrics port;
10256:http healthz port;
查看 ipvs 路由規則
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "/usr/sbin/ipvsadm -ln"
done
輸出:
172.16.10.101
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 10.254.0.1:443 rr persistent 10800
-> 172.16.10.100:6443 Masq 1 0 0
172.16.10.102
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 10.254.0.1:443 rr persistent 10800
-> 172.16.10.100:6443 Masq 1 0 0
172.16.10.103
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 10.254.0.1:443 rr persistent 10800
-> 172.16.10.100:6443 Masq 1 0 0
8、驗證集羣功能
檢查節點狀態
[k8s@kube-server ~]$kubectl get nodes
NAME STATUS ROLES AGE VERSION
kube-node1 Ready 4h v1.10.4
kube-node2 Ready 4h v1.10.4
kube-node3 Ready 4h v1.10.4
創建測試文件
cat > nginx-ds.yml <
apiVersion: v1
kind: Service
metadata:
name: nginx-ds
labels:
app: nginx-ds
spec:
type: NodePort
selector:
app: nginx-ds
ports:
- name: http
port: 80
targetPort: 80
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
name: nginx-ds
labels:
addonmanager.kubernetes.io/mode: Reconcile
spec:
template:
metadata:
labels:
app: nginx-ds
spec:
containers:
- name: my-nginx
image: nginx:1.7.9
ports:
- containerPort: 80
EOF
執行定義文件
[k8s@kube-server ~]$ kubectl create -f nginx-ds.yml
service "nginx-ds" created
daemonset.extensions "nginx-ds" created
檢查各 Node 上的 Pod IP 連通性
[k8s@kube-server ~]$ kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE
nginx-ds-8h4j5 1/1 Running 0 5m 172.30.49.2 kube-node1
nginx-ds-kxx7r 1/1 Running 0 5m 172.30.7.2 kube-node2
nginx-ds-ndnf5 1/1 Running 0 5m 172.30.48.2 kube-node3
可見,nginx-ds 的 Pod IP 分別是 172.30.49.2、172.30.7.2、172.30.48.2,在所有 Node 上分別 ping 這三個 IP,看是否連通:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh ${node_ip} "ping -c 1 172.30.49.2"
ssh ${node_ip} "ping -c 1 172.30.7.2"
ssh ${node_ip} "ping -c 1 172.30.48.2"
done
檢查服務 IP 和端口可達性
[k8s@kube-server ~]$ kubectl get svc |grep nginx-ds
nginx-ds NodePort 10.254.220.112 80:8880/TCP 4h
可見:
Service Cluster IP:10.254.220.112
服務端口:80
NodePort 端口:8900
在所有 Node 上 curl Service IP:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh ${node_ip} "curl 10.254.220.112"
done
預期輸出 nginx 歡迎頁面內容。
檢查服務的 NodePort 可達性
在所有 Node 上執行:
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh ${node_ip} "curl ${node_ip}:8900"
done
預期輸出 nginx 歡迎頁面內容。
9、部署集羣插件
插件是集羣的附件組件,豐富和完善了集羣的功能。
coredns
Dashboard
Heapster (influxdb、grafana)
Metrics Server
EFK (elasticsearch、fluentd、kibana)
9.1 部署 coredns 插件
修改配置文件
將下載的 kubernetes-server-linux-amd64.tar.gz 解壓後,再解壓其中的 kubernetes-src.tar.gz 文件。
coredns 對應的目錄是:cluster/addons/dns。
[k8s@kube-server dns]$ pwd
/home/k8s/kubernetes/cluster/addons/dns
[k8s@kube-server dns]$ ls
coredns.yaml.base coredns.yaml.sed kube-dns.yaml.in Makefile README.md transforms2sed.sed
coredns.yaml.in kube-dns.yaml.base kube-dns.yaml.sed OWNERS transforms2salt.sed
[k8s@kube-server dns]$
[k8s@kube-server dns]$ cp coredns.yaml.base coredns.yaml
[k8s@kube-server dns]$ vi coredns.yaml
[k8s@kube-server dns]$ diff coredns.yaml.base coredns.yaml
61c61
< kubernetes PILLAR__DNS__DOMAIN in-addr.arpa ip6.arpa {
kubernetes cluster.local. in-addr.arpa ip6.arpa {
153c153
< clusterIP: PILLAR__DNS__SERVER
clusterIP: 10.254.0.2
[k8s@kube-server dns]$ kubectl create -f coredns.yaml
serviceaccount "coredns" created
clusterrole.rbac.authorization.k8s.io "system:coredns" created
clusterrolebinding.rbac.authorization.k8s.io "system:coredns" created
configmap "coredns" created
deployment.extensions "coredns" created
service "coredns" created
[k8s@kube-server dns]$
檢查 coredns 功能
[k8s@kube-server dns]$ kubectl get all -n kube-system
NAME READY STATUS RESTARTS AGE
pod/coredns-77c989547b-bq6ff 1/1 Running 0 31s
pod/coredns-77c989547b-m8qhw 1/1 Running 0 31s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/coredns ClusterIP 10.254.0.2 53/UDP,53/TCP 31s
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
deployment.apps/coredns 2 2 2 2 31s
NAME DESIRED CURRENT READY AGE
replicaset.apps/coredns-77c989547b 2 2 2 31s
[k8s@kube-server dns]$
新建一個 測試Deployment
cat > my-nginx.yaml <
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: my-nginx
spec:
replicas: 2
template:
metadata:
labels:
run: my-nginx
spec:
containers:
- name: my-nginx
image: nginx:1.7.9
ports:
EOF
[k8s@kube-server ~]$ kubectl create -f my-nginx.yaml
deployment.extensions "my-nginx" created
export 該 Deployment, 生成 my-nginx 服務:
[k8s@kube-server ~]$ kubectl expose deploy my-nginx
service "my-nginx" exposed
[k8s@kube-server ~]$ kubectl get services --all-namespaces |grep my-nginx
default my-nginx ClusterIP 10.254.191.237 80/TCP 8s
創建另一個測試 Pod
查看 /etc/resolv.conf 是否包含 kubelet 配置的 --cluster-dns 和 --cluster-domain,是否能夠將服務 my-nginx 解析到上面顯示的 Cluster IP 10.254.191.237
cat > pod-nginx.yaml <
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
ports:
- containerPort: 80
EOF
[k8s@kube-server ~]$ kubectl exec -it nginx -c nginx /bin/bash
root@nginx:/# ip a
1: lo: mtu 65536 qdisc noqueue state UNKNOWN qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
14: eth0@if15: mtu 1450 qdisc noqueue state UP
link/ether 02:42:ac:1e:30:04 brd ff:ff:ff:ff:ff:ff
inet 172.30.48.4/24 brd 172.30.48.255 scope global eth0
valid_lft forever preferred_lft forever
root@nginx:/# ping kubernetes
PING kubernetes.default.svc.cluster.local (10.254.0.1): 48 data bytes
56 bytes from 10.254.0.1: icmp_seq=0 ttl=64 time=0.050 ms
56 bytes from 10.254.0.1: icmp_seq=1 ttl=64 time=0.076 ms
56 bytes from 10.254.0.1: icmp_seq=2 ttl=64 time=0.143 ms
56 bytes from 10.254.0.1: icmp_seq=3 ttl=64 time=0.079 ms
^C--- kubernetes.default.svc.cluster.local ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.050/0.087/0.143/0.034 ms
root@nginx:/# ping my-nginx
PING my-nginx.default.svc.cluster.local (10.254.191.237): 48 data bytes
56 bytes from 10.254.191.237: icmp_seq=0 ttl=64 time=0.094 ms
56 bytes from 10.254.191.237: icmp_seq=1 ttl=64 time=0.113 ms
^C--- my-nginx.default.svc.cluster.local ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.094/0.104/0.113/0.000 ms
root@nginx:/# ping coredns
ping: unknown host
root@nginx:/# ping coredns.kube-system.svc.cluster.local
PING coredns.kube-system.svc.cluster.local (10.254.0.2): 48 data bytes
56 bytes from 10.254.0.2: icmp_seq=0 ttl=64 time=0.042 ms
56 bytes from 10.254.0.2: icmp_seq=1 ttl=64 time=0.095 ms
^C--- coredns.kube-system.svc.cluster.local ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.042/0.069/0.095/0.027 ms
root@nginx:/#
root@nginx:/# cat /etc/resolv.conf
nameserver 10.254.0.2
search default.svc.cluster.local. svc.cluster.local. cluster.local.
options ndots:5
root@nginx:/#
9.2 部署 dashboard 插件
修改配置文件
將下載的 kubernetes-server-linux-amd64.tar.gz 解壓後,再解壓其中的 kubernetes-src.tar.gz 文件。
dashboard 對應的目錄是:cluster/addons/dashboard。
$ pwd
/opt/k8s/kubernetes/cluster/addons/dashboard
$ cp dashboard-controller.yaml{,.orig}
$ diff dashboard-controller.yaml{,.orig}
33c33
< image: siriuszg/kubernetes-dashboard-amd64:v1.8.3
image: k8s.gcr.io/kubernetes-dashboard-amd64:v1.8.3
$ cp dashboard-service.yaml{,.orig}
$ diff dashboard-service.yaml.orig dashboard-service.yaml
10a11
type: NodePort
指定端口類型爲 NodePort,這樣外界可以通過地址 nodeIP:nodePort 訪問 dashboard。
更換了一個容器鏡像的下載地址。
執行所有定義文件
[k8s@kube-server dashboard]$ ls *.yaml
dashboard-configmap.yaml dashboard-controller.yaml dashboard-rbac.yaml dashboard-secret.yaml dashboard-service.yaml
[k8s@kube-server dashboard]$ kubectl create -f .
configmap "kubernetes-dashboard-settings" created
serviceaccount "kubernetes-dashboard" created
deployment.apps "kubernetes-dashboard" created
role.rbac.authorization.k8s.io "kubernetes-dashboard-minimal" created
rolebinding.rbac.authorization.k8s.io "kubernetes-dashboard-minimal" created
secret "kubernetes-dashboard-certs" created
secret "kubernetes-dashboard-key-holder" created
service "kubernetes-dashboard" created
[k8s@kube-server dashboard]$
查看分配的 NodePort
[k8s@kube-server dashboard]$ kubectl get deployment kubernetes-dashboard -n kube-system
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
kubernetes-dashboard 1 1 1 1 50s
[k8s@kube-server dashboard]$ kubectl --namespace kube-system get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE
coredns-77c989547b-bq6ff 1/1 Running 558 1d 172.30.49.3 kube-node1
coredns-77c989547b-m8qhw 1/1 Running 556 1d 172.30.48.3 kube-node3
kubernetes-dashboard-65f7b4f486-j659c 1/1 Running 0 7m 172.30.7.2 kube-node2
[k8s@kube-server dashboard]$ kubectl get services kubernetes-dashboard -n kube-system
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes-dashboard NodePort 10.254.56.169 443:8645/TCP 8m
NodePort 8645 映射到 dashboard pod 443 端口
dashboard 的 --authentication-mode 支持 token、basic,默認爲 token。如果使用 basic,則 kube-apiserver 必須配置 '--authorization-mode=ABAC' 和 '--basic-auth-file' 參數。
查看 dashboard 支持的命令行參數
kubectl exec --namespace kube-system -it kubernetes-dashboard-65f7b4f486-j659c -- /dashboard --help
訪問 dashboard
爲了集羣安全,從 1.7 開始,dashboard 只允許通過 https 訪問,如果使用 kube proxy 則必須監聽 localhost 或 127.0.0.1,對於 NodePort 沒有這個限制,但是僅建議在開發環境中使用。
對於不滿足這些條件的登錄訪問,在登錄成功後瀏覽器不跳轉,始終停在登錄界面。
- kubernetes-dashboard 服務暴露了 NodePort,可以使用 http://NodeIP:NodePort 地址訪問 dashboard;
- 通過 kube-apiserver 訪問 dashboard;
- 通過 kubectl proxy 訪問 dashboard:
如果使用了 VirtualBox,需要啓用 VirtualBox 的 ForworadPort 功能將虛機監聽的端口和 Host 的本地端口綁定。
通過 kubectl proxy 訪問 dashboard
啓動代理:
[k8s@kube-node2 ~]$ kubectl proxy --address='localhost' --port=8086 --accept-hosts='^*$'
Starting to serve on 127.0.0.1:8086
--address 必須爲 localhost 或 127.0.0.1;
需要指定 --accept-hosts 選項,否則瀏覽器訪問 dashboard 頁面時提示 “Unauthorized”;
瀏覽器訪問 URL:http://127.0.0.1:8086/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy
注:上面的方式最終沒有調試通,不知是端口轉發哪裏沒設置正確。
通過 kube-apiserver 訪問 dashboard
獲取集羣服務地址列表:
[root@kube-server ~]# kubectl cluster-info
Kubernetes master is running at https://172.16.10.100:6443
CoreDNS is running at https://172.16.10.100:6443/api/v1/namespaces/kube-system/services/coredns:dns/proxy
kubernetes-dashboard is running at https://172.16.10.100:6443/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
必須通過 kube-apiserver 的安全端口(https)訪問 dashbaord,訪問時瀏覽器需要使用自定義證書,否則會被 kube-apiserver 拒絕訪問。
創建登錄 Dashboard 的 token 和 kubeconfig 配置文件
上面提到,Dashboard 默認只支持 token 認證,所以如果使用 KubeConfig 文件,需要在該文件中指定 token,不支持使用 client 證書認證。
創建登錄 token
[k8s@kube-server ~]$ kubectl create sa dashboard-admin -n kube-system
serviceaccount "dashboard-admin" created
[k8s@kube-server ~]$ kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
clusterrolebinding.rbac.authorization.k8s.io "dashboard-admin" created
[k8s@kube-server ~]$ ADMIN_SECRET=$(kubectl get secrets -n kube-system | grep dashboard-admin | awk '{print $1}')
[k8s@kube-server ~]$ DASHBOARD_LOGIN_TOKEN=$(kubectl describe secret -n kube-system ${ADMIN_SECRET} | grep -E '^token' | awk '{print $2}')
[k8s@kube-server ~]$ echo ${DASHBOARD_LOGIN_TOKEN}
eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.jgQo6TtcGugKQOlcXbe9-dqoP1_YkKshbeeqMudZOFVigDgSKPAUYNH4LbIqOBoAMnsZxKJPFFd36wR5JRzqUy5hI6cSRhBZr7_XiAZYeAdt0ZmbTq_ZM-Y0HDnokhxonwmV08TkVffj85uLnHUY5IZFYKmiiEUuSecek8LWVqvUAgBj1TIeKyGr5FGYxk2KCzlkHU90yFlhSjN4VqE-YkG7TJuV-2ge2sBWhmnqodrWhOHMD7_CQP-WzZxjPZY-WbznYNrBbuVOkJVjOyaf6EB0lzx1bpMSSeVhkWA3a_BdxOEWEx-OuvQgIxqqn0cY27om5xKItR-B4DiyrKyu6w
[k8s@kube-server ~]$
使用輸出的 token 登錄 Dashboard。
創建使用 token 的 KubeConfig 文件
source /opt/k8s/bin/environment.sh
設置集羣參數
kubectl config set-cluster kubernetes \
--certificate-authority=/etc/kubernetes/cert/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=dashboard.kubeconfig
設置客戶端認證參數,使用上面創建的 Token
kubectl config set-credentials dashboard_user \
--token=${DASHBOARD_LOGIN_TOKEN} \
--kubeconfig=dashboard.kubeconfig
設置上下文參數
kubectl config set-context default \
--cluster=kubernetes \
--user=dashboard_user \
--kubeconfig=dashboard.kubeconfig
設置默認上下文
kubectl config use-context default --kubeconfig=dashboard.kubeconfig
用生成的 dashboard.kubeconfig 登錄 Dashboard。
由於缺少 Heapster 插件,當前 dashboard 不能展示 Pod、Nodes 的 CPU、內存等統計數據和圖表。
9.3 部署 heapster 插件
Heapster是一個收集者,將每個Node上的cAdvisor的數據進行彙總,然後導到第三方工具(如InfluxDB)。
Heapster 是通過調用 kubelet 的 http API 來獲取 cAdvisor 的 metrics 數據的。
由於 kublet 只在 10250 端口接收 https 請求,故需要修改 heapster 的 deployment 配置。同時,需要賦予 kube-system:heapster ServiceAccount 調用 kubelet API 的權限。
下載 heapster 文件
到 heapster release 頁面 下載最新版本的 heapster
wget https://github.com/kubernetes/heapster/archive/v1.5.3.tar.gz
tar -xzvf v1.5.3.tar.gz
mv v1.5.3.tar.gz heapster-1.5.3.tar.gz
官方文件目錄: heapster-1.5.3/deploy/kube-config/influxdb
修改配置
[k8s@kube-server ~]$ cd heapster-1.5.3/deploy/kube-config/influxdb
[k8s@kube-server influxdb]$ ls
grafana.yaml heapster.yaml influxdb.yaml
[k8s@kube-server influxdb]$ cp grafana.yaml{,.orig}
[k8s@kube-server influxdb]$ vi grafana.yaml
[k8s@kube-server influxdb]$ diff grafana.yaml.orig grafana.yaml
16c16
< image: gcr.io/google_containers/heapster-grafana-amd64:v4.4.3
image: wanghkkk/heapster-grafana-amd64-v4.4.3:v4.4.3
67c67
< # type: NodePort
type: NodePort
[k8s@kube-server influxdb]$
更換國內可訪問的鏡像,並開啓 NodePort
[k8s@kube-server influxdb]$ cp heapster.yaml{,.orig}
[k8s@kube-server influxdb]$ vi heapster.yaml
[k8s@kube-server influxdb]$ diff heapster.yaml.orig heapster.yaml
23c23
< image: gcr.io/google_containers/heapster-amd64:v1.5.3
image: fishchen/heapster-amd64:v1.5.3
27c27
< - --source=kubernetes:https://kubernetes.default
- --source=kubernetes:https://kubernetes.default?kubeletHttps=true&kubeletPort=10250
[k8s@kube-server influxdb]$
由於 kubelet 只在 10250 監聽 https 請求,故添加相關參數。
[k8s@kube-server influxdb]$ cp influxdb.yaml{,.orig}
[k8s@kube-server influxdb]$ vi influxdb.yaml
[k8s@kube-server influxdb]$ diff influxdb.yaml.orig influxdb.yaml
16c16
< image: gcr.io/google_containers/heapster-influxdb-amd64:v1.3.3
image: fishchen/heapster-influxdb-amd64:v1.3.3
[k8s@kube-server influxdb]$
執行所有定義文件
[k8s@kube-server influxdb]$ pwd
/home/k8s/heapster-1.5.3/deploy/kube-config/influxdb
[k8s@kube-server influxdb]$ ls *.yaml
grafana.yaml heapster.yaml influxdb.yaml
[k8s@kube-server influxdb]$ kubectl create -f .
deployment.extensions "monitoring-grafana" created
service "monitoring-grafana" created
serviceaccount "heapster" created
deployment.extensions "heapster" created
service "heapster" created
deployment.extensions "monitoring-influxdb" created
service "monitoring-influxdb" created
[k8s@kube-server influxdb]$
$ cd ../rbac/
$ pwd
/opt/k8s/heapster-1.5.2/deploy/kube-config/rbac
$ ls
heapster-rbac.yaml
[k8s@kube-server rbac]$ cp heapster-rbac.yaml{,.orig}
[k8s@kube-server rbac]$ vi heapster-rbac.yaml
[k8s@kube-server rbac]$ diff heapster-rbac.yaml.orig heapster-rbac.yaml
4c4
< name: heapster
name: heapster-kubelet-api
8c8
< name: system:heapster
name: system:kubelet-api-admin
[k8s@kube-server rbac]$ kubectl create -f heapster-rbac.yaml
clusterrolebinding.rbac.authorization.k8s.io "heapster-kubelet-api" created
[k8s@kube-server rbac]$
將 serviceAccount kube-system:heapster 與 ClusterRole system:kubelet-api-admin 綁定,授予它調用 kubelet API 的權限。
檢查執行結果
[k8s@kube-server rbac]$ kubectl get pods -n kube-system | grep -E 'heapster|monitoring'
heapster-7648ffc7c9-qfvtd 1/1 Running 0 18m
monitoring-grafana-5986995c7b-dlqn4 0/1 ImagePullBackOff 0 18m
monitoring-influxdb-f75847d48-pd97v 1/1 Running 0 18m
檢查 kubernets dashboard 界面,可以正確顯示各 Nodes、Pods 的 CPU、內存、負載等統計數據和圖表了。
訪問 grafana
1.通過 kube-apiserver 訪問:
獲取 monitoring-grafana 服務 URL:
[k8s@kube-server influxdb]$ kubectl cluster-info
Kubernetes master is running at https://172.16.10.100:6443
CoreDNS is running at https://172.16.10.100:6443/api/v1/namespaces/kube-system/services/coredns:dns/proxy
Heapster is running at https://172.16.10.100:6443/api/v1/namespaces/kube-system/services/heapster/proxy
kubernetes-dashboard is running at https://172.16.10.100:6443/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy
monitoring-grafana is running at https://172.16.10.100:6443/api/v1/namespaces/kube-system/services/monitoring-grafana/proxy
monitoring-influxdb is running at https://172.16.10.100:6443/api/v1/namespaces/kube-system/services/monitoring-influxdb/proxy
使用瀏覽器訪問:https://172.16.10.100:6443/api/v1/namespaces/kube-system/services/monitoring-grafana/proxy即可。
注:本以爲需要在virtualbox上做個端口轉發才行,結果發現在virtualbox上給kube-server,kube-node1,2,3的第2塊網卡所設置的Host-Only網絡,實際上支持從PC主機上直接訪問到這幾個虛機的Host-Only網卡地址與服務端口!
- 通過 kubectl proxy 訪問:
創建代理
kubectl proxy --address='172.16.10.100' --port=8086 --accept-hosts='^*$'
Starting to serve on 172.16.10.100:8086
瀏覽器訪問 URL:http://172.16.10.100:8086/api/v1/namespaces/kube-system/services/monitoring-grafana/proxy/?orgId=1
- 通過 NodePort 訪問:
[k8s@kube-server influxdb]$ kubectl get svc -n kube-system|grep -E 'monitoring|heapster'
heapster ClusterIP 10.254.14.104 80/TCP 58m
monitoring-grafana NodePort 10.254.36.0 80:8995/TCP 58m
monitoring-influxdb ClusterIP 10.254.206.219 8086/TCP 58m
grafana 監聽 NodePort 8995;
瀏覽器訪問 URL:http://172.16.10.101:8995/?orgId=1
9.4 部署 metrics-server 插件
metrics-server爲通過api的方式提供nodes或pods的資源使用指標提供支持。目前主要是在HPA自動伸縮和Scheduler自動調度中得到應用。
創建 metrics-server 使用的證書
創建 metrics-server 證書籤名請求:
cat > metrics-server-csr.json <
{
"CN": "aggregator",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "testcorp"
}
]
}
EOF
注意: CN 名稱爲 aggregator,需要與 kube-apiserver 的 --requestheader-allowed-names 參數配置一致。
生成 metrics-server 證書和私鑰:
cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
-ca-key=/etc/kubernetes/cert/ca-key.pem \
-config=/etc/kubernetes/cert/ca-config.json \
-profile=kubernetes metrics-server-csr.json | cfssljson -bare metrics-server
將生成的證書和私鑰文件拷貝到 kube-apiserver 節點:
cp metrics-server*.pem /etc/kubernetes/cert/
修改 kubernetes 控制平面組件的配置以支持 metrics-server
kube-apiserver添加如下配置參數:
--requestheader-client-ca-file=/etc/kubernetes/cert/ca.pem
--requestheader-allowed-names=aggregator
--requestheader-extra-headers-prefix="X-Remote-Extra-"
--requestheader-group-headers=X-Remote-Group
--requestheader-username-headers=X-Remote-User
--proxy-client-cert-file=/etc/kubernetes/cert/metrics-server.pem
--proxy-client-key-file=/etc/kubernetes/cert/metrics-server-key.pem
--runtime-config=api/all=true
--enable-aggregator-routing=true
--requestheader-XXX、--proxy-client-XXX 是 kube-apiserver 的 aggregator layer 相關的配置參數,metrics-server & HPA 需要使用;
--requestheader-client-ca-file:用於簽名 --proxy-client-cert-file 和 --proxy-client-key-file 指定的證書;在啓用了 metric aggregator 時使用;
如果 --requestheader-allowed-names 不爲空,則--proxy-client-cert-file 證書的 CN 必須位於 allowed-names 中,默認爲 aggregator;
如果 kube-apiserver 機器沒有運行 kube-proxy,則還需要添加 --enable-aggregator-routing=true 參數。
注意:requestheader-client-ca-file 指定的 CA 證書,必須具有 client auth and server auth。
kube-controller-manager添加如下配置參數:
--horizontal-pod-autoscaler-use-rest-clients=true
用於配置 HPA 控制器使用 REST 客戶端獲取 metrics 數據。
修改過啓動參數後,需要重啓服務以生效。
systemctl daemon-reload
systemctl restart kube-apiserver && systemctl status kube-apiserver
systemctl daemon-reload
systemctl restart kube-controller-manager && systemctl status kube-controller-manager
修改插件配置文件配置文件
metrics-server 插件位於 kubernetes 的 cluster/addons/metrics-server/ 目錄下。
修改 metrics-server-deployment 文件:
[k8s@kube-server metrics-server]$ cp metrics-server-deployment.yaml{,.orig}
[k8s@kube-server metrics-server]$ vi metrics-server-deployment.yaml
[k8s@kube-server metrics-server]$ diff metrics-server-deployment.yaml.orig metrics-server-deployment.yaml
51c51
< image: k8s.gcr.io/metrics-server-amd64:v0.2.1
image: mirrorgooglecontainers/metrics-server-amd64:v0.2.1
54c54
< - --source=kubernetes.summary_api:''
- --source=kubernetes.summary_api:https://kubernetes.default?kubeletHttps=true&kubeletPort=10250
60c60
< image: k8s.gcr.io/addon-resizer:1.8.1
image: siriuszg/addon-resizer:1.8.1
[k8s@kube-server metrics-server]$
metrics-server 的參數格式與 heapster 類似。由於 kubelet 只在 10250 監聽 https 請求,故添加相關參數。
授予 kube-system:metrics-server ServiceAccount 訪問 kubelet API 的權限:
[k8s@kube-server metrics-server]$ cat auth-kubelet.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: metrics-server:system:kubelet-api-admin
labels:
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: system:kubelet-api-admin
subjects:
- kind: ServiceAccount
name: metrics-server
namespace: kube-system
[k8s@kube-server metrics-server]$
新建一個 ClusterRoleBindings 定義文件,授予相關權限。
創建 metrics-server
[k8s@kube-server metrics-server]$ pwd
/home/k8s/kubernetes/cluster/addons/metrics-server
[k8s@kube-server metrics-server]$ ls -l *.yaml
-rw-rw-r--. 1 k8s k8s 398 Jun 4 23:17 auth-delegator.yaml
-rw-rw-r--. 1 k8s k8s 404 Jun 29 13:40 auth-kubelet.yaml
-rw-rw-r--. 1 k8s k8s 419 Jun 4 23:17 auth-reader.yaml
-rw-rw-r--. 1 k8s k8s 393 Jun 4 23:17 metrics-apiservice.yaml
-rw-rw-r--. 1 k8s k8s 2650 Jun 29 13:21 metrics-server-deployment.yaml
-rw-rw-r--. 1 k8s k8s 336 Jun 4 23:17 metrics-server-service.yaml
-rw-rw-r--. 1 k8s k8s 801 Jun 4 23:17 resource-reader.yaml
[k8s@kube-server metrics-server]$ kubectl create -f .
clusterrolebinding.rbac.authorization.k8s.io "metrics-server:system:auth-delegator" created
clusterrolebinding.rbac.authorization.k8s.io "metrics-server:system:kubelet-api-admin" created
rolebinding.rbac.authorization.k8s.io "metrics-server-auth-reader" created
apiservice.apiregistration.k8s.io "v1beta1.metrics.k8s.io" created
serviceaccount "metrics-server" created
configmap "metrics-server-config" created
deployment.extensions "metrics-server-v0.2.1" created
service "metrics-server" created
clusterrole.rbac.authorization.k8s.io "system:metrics-server" created
clusterrolebinding.rbac.authorization.k8s.io "system:metrics-server" created
[k8s@kube-server metrics-server]$
查看運行情況
[k8s@kube-server metrics-server]$ kubectl get pods -n kube-system |grep metrics-server
metrics-server-v0.2.1-86946dfbfb-4fxvz 2/2 Running 0 5m
[k8s@kube-server metrics-server]$ kubectl get svc -n kube-system|grep metrics-server
metrics-server ClusterIP 10.254.71.71 443/TCP 6m
查看 metrics-server 輸出的 metrics
metrics-server 輸出的 APIs:https://github.com/kubernetes/community/blob/master/contributors/design-proposals/instrumentation/resource-metrics-api.md
1.通過 kube-apiserver 或 kubectl proxy 訪問:
https://172.16.10.100:6443/apis/metrics.k8s.io/v1beta1/nodes
https://172.16.10.100:6443/apis/metrics.k8s.io/v1beta1/nodes/
https://172.16.10.100:6443/apis/metrics.k8s.io/v1beta1/pods
https://172.16.10.100:6443/apis/metrics.k8s.io/v1beta1/namespace//pods/
2.直接使用 kubectl 命令訪問:
kubectl get --raw apis/metrics.k8s.io/v1beta1/nodes
kubectl get --raw apis/metrics.k8s.io/v1beta1/pods
kubectl get --raw /apis/metrics.k8s.io/v1beta1/nodes/
kubectl get --raw /apis/metrics.k8s.io/v1beta1/namespace//pods/
kubectl get --raw "/apis/metrics.k8s.io/v1beta1" | jq .
kubectl get --raw "/apis/metrics.k8s.io/v1beta1/nodes" | jq .
注:/apis/metrics.k8s.io/v1beta1/nodes 和 /apis/metrics.k8s.io/v1beta1/pods 返回的 usage 包含 CPU 和 Memory 。
注:以上查看metrics的操作執行時報錯,暫未找到答案。錯誤信息主要是:
[k8s@kube-server metrics-server]$ kubectl get --raw "/apis/metrics.k8s.io/v1beta1/nodes" | jq .
Error from server (Forbidden): nodes.metrics.k8s.io is forbidden: User "aggregator" cannot list nodes.metrics.k8s.io at the cluster scope.
9.5 EFK插件
EFK 對應的目錄:kubernetes/cluster/addons/fluentd-elasticsearch
[k8s@kube-server addons]$ pwd
/home/k8s/kubernetes/cluster/addons
[k8s@kube-server addons]$ cd fluentd-elasticsearch/
[k8s@kube-server fluentd-elasticsearch]$ ls
es-image es-statefulset.yaml fluentd-es-ds.yaml kibana-deployment.yaml OWNERS README.md
es-service.yaml fluentd-es-configmap.yaml fluentd-es-image kibana-service.yaml podsecuritypolicies
[k8s@kube-server fluentd-elasticsearch]$
修改定義文件
$ cp es-statefulset.yaml{,.orig}
$ diff es-statefulset.yaml{,.orig}
76c76
< - image: netonline/elasticsearch:v5.6.4
- image: k8s.gcr.io/elasticsearch:v5.6.4
$ cp fluentd-es-ds.yaml{,.orig}
$ diff fluentd-es-ds.yaml{,.orig}
79c79
< image: netonline/fluentd-elasticsearch:v2.0.4
image: k8s.gcr.io/fluentd-elasticsearch:v2.0.4
給 Node 設置標籤
DaemonSet fluentd-es 只會調度到設置了標籤 beta.kubernetes.io/fluentd-ds-ready=true 的 Node,需要在期望運行 fluentd 的 Node 上設置該標籤;
[k8s@kube-server fluentd-elasticsearch]$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
kube-node1 Ready 3d v1.10.4
kube-node2 Ready 3d v1.10.4
kube-node3 Ready 3d v1.10.4
[k8s@kube-server fluentd-elasticsearch]$ kubectl label nodes kube-node3 beta.kubernetes.io/fluentd-ds-ready=true
node "kube-node3" labeled
[k8s@kube-server fluentd-elasticsearch]$
執行定義文件
[k8s@kube-server fluentd-elasticsearch]$ kubectl create -f .
service "elasticsearch-logging" created
serviceaccount "elasticsearch-logging" created
clusterrole.rbac.authorization.k8s.io "elasticsearch-logging" created
clusterrolebinding.rbac.authorization.k8s.io "elasticsearch-logging" created
statefulset.apps "elasticsearch-logging" created
configmap "fluentd-es-config-v0.1.4" created
serviceaccount "fluentd-es" created
clusterrole.rbac.authorization.k8s.io "fluentd-es" created
clusterrolebinding.rbac.authorization.k8s.io "fluentd-es" created
daemonset.apps "fluentd-es-v2.0.4" created
deployment.apps "kibana-logging" created
service "kibana-logging" created
[k8s@kube-server fluentd-elasticsearch]$
檢查執行結果
kubectl get pods -n kube-system -o wide|grep -E 'elasticsearch|fluentd|kibana'
kubectl get service -n kube-system|grep -E 'elasticsearch|kibana'
kibana Pod 第一次啓動時會用較長時間(0-20分鐘)來優化和 Cache 狀態頁面,可以 tailf 該 Pod 的日誌觀察進度:
kubectl logs kibana-logging-7445dc9757-jbzvd -n kube-system -f
注意:只有當的 Kibana pod 啓動完成後,才能查看 kibana dashboard,否則會提示 refuse。
訪問 kibana
通過 kube-apiserver 訪問:
kubectl cluster-info|grep -E 'Elasticsearch|Kibana'
通過 kubectl proxy 訪問:
創建代理
$ kubectl proxy --address='172.16.10.100' --port=8086 --accept-hosts='^*$'
瀏覽器訪問 URL:http://172.16.10.100:8086/api/v1/namespaces/kube-system/services/kibana-logging/proxy
在 Settings -> Indices 頁面創建一個 index(相當於 mysql 中的一個 database),選中 Index contains time-based events,使用默認的 logstash-* pattern,點擊 Create ;
創建 Index 後,稍等幾分鐘就可以在 Discover 菜單下看到 ElasticSearch logging 中匯聚的日誌;
注:因爲我的模擬測試環境中在一臺極爲普通的PC機上搭建的,在運行了上面這套EFK環境後,磁盤IO基本就跑不過來了,導致各種服務沒響應,最終還是手動又刪除了EFK。
問題記錄:
1、網卡hairpin_mode設置
在準備配置環境的過程中,就要求設置docker網卡的hairpin_mode,不太理解在未安裝docker時爲什麼要求設置這個,且確實無法設置,因爲此時連docker也還沒有安裝。
注:hairpin_mode模式下,虛機或容器間的流量強制要求必須經過物理交換機才能通信。
2、設置系統參數net.bridge.bridge-nf-call-iptables=1(打開iptables管理網橋的功能)
在各節點上執行以下命令:
modprobe br_netfilter
cat > /etc/sysctl.d/kubernetes.conf <
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv4.ip_forward=1
EOF
sysctl -p /etc/sysctl.d/kubernetes.conf
原文中把modprobe br_netfilter放在最後執行的,實際情況是應該首先執行這條命令。
3、授予 kubernetes 證書訪問 kubelet API 的權限的命令的執行順序錯誤
應該在成功啓動了kube-apiserver服務後再執行該命令。
4、在部署kube-apiserver服務中,製作密鑰的證書請求中使用了無法解析的域名kubernetes.default.svc.cluster.local.
該問題已經確認爲是go v1.9中的域名語法校驗解析bug。在6.29號的最新版本的部署材料中已經發現和糾正了該問題。但此故障引發的coreDNS部署失敗並報以下錯誤,已經摺騰了我2天時間尋求答案!
E0628 08:10:41.256264 1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:319: Failed to list *v1.Namespace: Get https://10.254.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: tls: failed to parse certificate from server: x509: cannot parse dnsName "kubernetes.default.svc.cluster.local."
關於該bug的修復說明:
5、關於怎麼使用admin密鑰訪問api接口
下面是正確的方式:
curl -sSL --cacert /etc/kubernetes/cert/ca.pem --cert /home/k8s/admin.pem --key /home/k8s/admin-key.pem https://172.16.10.100:6443/api/v1/endpoints
本文轉自CSDN-k8s v1.10部署筆記