k8s中文文檔

k8s概念比較多，有什麼概念的疑惑的推薦看k8s中文文檔。

me的環境

操作系統：centos7
docker：1.12.6

環境跟me的不一致？不要慌，基本大部分操作都是行的通的。

還慌？那就直接用網頁在線版的kubernets吧

kubernets單機版安裝部署

kubernetes部署算是有一定門檻的。爲了不從入門到放棄，推薦一開始安裝單機版作爲入門熟悉kubectl指令、瞭解工作原理。

安裝流程，切換成root

# 關閉centos自帶的防火牆

$ sudo systemctl disable firewalld

$ sudo systemctl stop firewalld

# 安裝etcd和kubernetes軟件（會自動安裝docker）

$ sudo yum install -y etcd kubernetes

修改兩處配置

Docker配置文件/etc/sysconfig/docker, OPTIONS=’–selinux-enabled=false –insecure-registry gcr.io’

# Modify these options if you want to change the way the docker daemon runs

OPTIONS='--selinux-enabled=false --insecure-registry gcr.io'

if [ -z "${DOCKER_CERT_PATH}" ]; then

DOCKER_CERT_PATH=/etc/docker

# Do not add registries in this file anymore. Use /etc/containers/registries.conf

# from the atomic-registries package.

# docker-latest daemon can be used by starting the docker-latest unitfile.

# To use docker-latest client, uncomment below lines

#DOCKERBINARY=/usr/bin/docker-latest

#DOCKERDBINARY=/usr/bin/dockerd-latest

#DOCKER_CONTAINERD_BINARY=/usr/bin/docker-containerd-latest

#DOCKER_CONTAINERD_SHIM_BINARY=/usr/bin/docker-containerd-shim-latest

Kubernetes apiservce配置文件/etc/kubernetes/apiserver,把–admission_control參數鐘的ServiceAccount刪除

###

# kubernetes system config

# The following values are used to configure the kube-apiserver

# The address on the local server to listen to.

KUBE_API_ADDRESS="--insecure-bind-address=0.0.0.0"

# The port on the local server to listen on.

# KUBE_API_PORT="--port=8080"

# Port minions listen on

# KUBELET_PORT="--kubelet-port=10250"

# Comma separated list of nodes in the etcd cluster

KUBE_ETCD_SERVERS="--etcd-servers=http://127.0.0.1:2379"

# Address range to use for services

KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"

# default admission control policies

KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"

# Add your own!

KUBE_API_ARGS=""

啓動所有服務

# systemctl start etcd

# systemctl start docker

# systemctl start kube-apiserver

# systemctl start kube-controller-manager

# systemctl start kube-scheduler

# systemctl start kubelet

# systemctl start kube-proxy

初入門小實例

部署nginx服務
$ kubectl run my-nginx --image=nginx --port=80

$ kubectl get pod # 查看pod

發現pod狀態無論多久都是處於pending。READY字段一直是0/1,服務部署失敗的原因是”中國牆“的問題導致無法下載pod啓動時需要的谷歌鏡像，所以我們得間接的創建所需的鏡像。

補充： Pending狀態表示API Server已經創建Pod，但Pod內還有一個或者多個容器沒有創建，或者正在下載鏡像的過程。詳細的參考Pod聲明週期和重啓策略

創建gcr.io/google_containers/pause-amd64:3.0鏡像
$ docker pull googlecontainer/pause-amd64:3.0

$ docker tag googlecontainer/pause-amd64:3.0 gcr.io/google_containers/pause-amd64:3.0

kubernets指令

實例流程

# 查看版本

$ kubectl version

Client Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.2", GitCommit:"269f928217957e7126dc87e6adfa82242bfe5b1e", GitTreeState:"clean", BuildDate:"2017-07-03T15:31:10Z", GoVersion:"go1.7.4", Compiler:"gc", Platform:"linux/amd64"}

Server Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.2", GitCommit:"269f928217957e7126dc87e6adfa82242bfe5b1e", GitTreeState:"clean", BuildDate:"2017-07-03T15:31:10Z", GoVersion:"go1.7.4", Compiler:"gc", Platform:"linux/amd64"}

# 顯示集羣信息

$ kubectl cluster-info

Kubernetes master is running at http://localhost:8080

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

# 查看集羣中有幾個Node

$ kubectl get nodes

NAME STATUS AGE

127.0.0.1 Ready 18h

# 運行一個鏡像

$ kubectl run my-nginx --image=nginx --replicas=2 --port=80

deployment "my-nginx" created

# 查看pod

$ kubectl get pods

NAME READY STATUS RESTARTS AGE

my-nginx-379829228-cwlbb 0/1 ContainerCreating 0 20s

my-nginx-379829228-czk6w 1/1 Running 0 20s

# 查看服務詳情信息

$ kubectl describe pod my-nginx-379829228-cwlbb

# 查看已部署

$ kubectl get deployments

NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE

my-nginx 2 2 2 2 3m

# 刪除pod

$ kubectl delete pod my-nginx-379829228-cwlbb

pod "my-nginx-379829228-cwlbb" deleted

# 再次查看pod，發現由於replicas機制，pod又生成一個新的

$ kubectl get pods

NAME READY STATUS RESTARTS AGE

my-nginx-379829228-czk6w 1/1 Running 0 11m

my-nginx-379829228-gjd7d 0/1 ContainerCreating 0 5s

# 刪除部署的my-nginx服務。徹底刪除pod

$ kubectl delete deployment my-nginx

deployment "my-nginx" deleted

對比docker命令

k8s的學習路線基本都是從docker[容器]到k8s的，因此兩個對比理解有助於記憶

# docker run

$ docker run -d -e DOMAIN=cluster --name my-nginx -p 80:80 nginx

$ kubectl run my-nginx --image=nginx --port=80 --env="DOMAIN=cluster"

# docker ps

$ docker ps

$ kubectl get pods

# docker exec

$ docker exec [容器id] ls

$ kubectl exec [pod_id] ls

# docker exec 交互式

$ docker exec -it [容器id] /bin/sh

$ kubectl exec -it [pod_id] -- /bin/sh

# docker info

$ docker info

$ kubectl cluster-info

重要名詞

名詞	翻譯
Namespace	命名空間
Endpoint	服務端點
Controller Manager	管理控制中心
Replication	副本控制器

yaml文件管理服務

用yaml文件來創建服務
# vi nginx.yaml

piVersion: extensions/v1beta1

kind: Deployment

metadata:

name: my-nginx

spec:

replicas: 3

template:

metadata:

labels:

app: nginx

spec:

containers:

- name: nginx

image: nginx:1.7.9

ports:

- containerPort: 80
啓動管理服務
# 根據yaml文件創建服務

$ kubectl create -f nginx.yaml

deployment "my-nginx" created

# 查看deployment

$ kubectl get deployments

NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE

my-nginx 3 3 3 3 6s

# 查看Pod

$ kubectl get pod

NAME READY STATUS RESTARTS AGE

my-nginx-4087004473-dtrjp 1/1 Running 0 7s

my-nginx-4087004473-jz80p 1/1 Running 0 7s

my-nginx-4087004473-wh576 1/1 Running 0 7s

# 根據yaml文件刪除服務

$ kubectl delete -f nginx.yaml

deployment "my-nginx" deleted

$ kubectl get pod

No resources found.

$ kubectl get deployment

No resources found.

Service

到此，我們部署一個nginx服務
$ kubectl run my-nginx --image=nginx --port=80

# 創建一個service 且將其暴露到集羣外可供訪問

$ kubectl expose deployment/my-nginx --type="NodePort" --port 80

service "my-nginx" exposed

# 此時service列表多個my-nginx服務

$ kubectl get services

NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE

kubernetes 10.254.0.1 <none> 443/TCP 7d

my-nginx 10.254.255.103 <nodes> 80:32589/TCP 7s

宿主主機內訪問該服務

$ kubectl describe service/my-nginx

# 顯示的字段有Endpoints: 172.17.0.2:80

$ curl 172.17.0.2.80

同網段的機器訪問該服務

$ curl 192.168.33.101:32589

deployments

# 運行nginx鏡像

$ kubectl run my-nginx --image=nginx --port=80

# 交互式 shell 的方式運行 pod

$ kubectl run -i --tty my-nginx --image=nginx --port=80 -- sh

# 鏈接到運行中的容器

$ kubectl attach my-nginx-532658988-10kxd -i

# 查看deployment

$ kubectl get deployments

NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE

my-nginx 1 1 1 1 25m

# 擴展10個副本

$ kubectl scale deployment my-nginx --replicas=10

deployment "my-nginx" scaled

$ kubectl scale deployment/my-nginx --replicas=10 # 作用效果等同上一條命令

deployment "my-nginx" scaled

# 再次顯示deployment

$ kubectl get deployments

NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE

my-nginx 10 10 10 1 26m

$ kubectl get pods

NAME READY STATUS RESTARTS AGE

my-nginx-379829228-38hkg 1/1 Running 0 5m

my-nginx-379829228-7j15l 1/1 Running 0 31m

my-nginx-379829228-c8mt3 1/1 Running 0 5m

my-nginx-379829228-f6mm8 1/1 Running 0 5m

my-nginx-379829228-q1rj0 1/1 Running 0 5m

my-nginx-379829228-qg7lf 1/1 Running 0 5m

my-nginx-379829228-rjfbq 1/1 Running 0 5m

my-nginx-379829228-v581r 1/1 Running 0 5m

my-nginx-379829228-wh49w 1/1 Running 0 5m

my-nginx-379829228-wpn98 1/1 Running 0 5m

# 縮擴到1個副本

$ kubectl scale deployment/my-nginx --replicas=1

deployment "my-nginx" scaled

$ kubectl scale deployment my-nginx --replicas=1 # 作用效果等同上一條命令

deployment的更新回滾

$ kubectl create -f nginx.yaml

$ kubectl get pod

NAME READY STATUS RESTARTS AGE

my-nginx-4087004473-4xj74 1/1 Running 0 3m

my-nginx-4087004473-jkptq 1/1 Running 0 3m

my-nginx-4087004473-m55s1 1/1 Running 0 3m

$ kubectl get deployment

NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE

my-nginx 3 3 3 3 4m

# 更新應用的鏡像從1.7.9版本——>1.9.1

$ kubectl set image deployment/my-nginx nginx=nginx:1.9.1

deployment "my-nginx" image updated

# 確認是否更新成功

$ kubectl rollout status deployment/my-nginx

deployment "my-nginx" successfully rolled out

# 回滾到上一代版本

$ kubectl rollout undo deployment/my-nginx

deployment "my-nginx" rolled back

ConfigMap-容器應用的配置管理

應用部署的一個最佳實踐是將應用所需配置信息和程序進行分離，一則程序可以更好的複用，二則能靈活的更改配置從而實現其他功能。

使用configMap替代環境變量

以yaml文件方式創建ConfigMap

# vi special-config.yaml

apiVersion: v1

kind: ConfigMap

metadata:

namespace: default

data:

special.how: very

special.type: charm

# vi env-config.yaml

apiVersion: v1

kind: ConfigMap

metadata:

namespace: default

data:

log_level: INFO

可以在Pod中這樣使用ConfigMap

# vi configMap.yaml

apiVersion: v1

kind: Pod

metadata:

spec:

containers:

- name: test-container

image: nginx

command: [ "/bin/sh", "-c", "env" ]

env:

- name: SPECIAL_LEVEL_KEY #定義環境變量名稱

valueFrom: #key"special.how"對應的值

configMapKeyRef:

key: special.how

- name: SPECIAL_TYPE_KEY

valueFrom:

configMapKeyRef:

key: special.type

restartPolicy: Never

啓動等一系列操作

$ kubectl create -f special-config.yaml

configmap "special-config" created

$ kubectl create -f env-config.yaml

configmap "env-config" created

# 查看ConfigMap

$ kubectl get configmaps

NAME DATA AGE

env-config 1 38m

special-config 2 39m

# 讓我們看一下創建的ConfigMap

$ kubectl describe configmap env-config

Name: env-config

Namespace: default

Labels: <none>

Annotations: <none>

Data

====

log_level: 4 bytes

# 查看ConfigMap鍵的值

$ kubectl get configmaps env-config -o yaml

apiVersion: v1

data:

log_level: INFO

kind: ConfigMap

metadata:

creationTimestamp: 2017-11-30T07:29:49Z

namespace: default

resourceVersion: "285268"

selfLink: /api/v1/namespaces/default/configmaps/env-config

uid: 3f473adf-d5a0-11e7-9830-0800275ae9e7

$ kubectl create -f configMap.yaml

pod "dapi-test-pod" created

# 查看pod，狀態ContainerCreating

$ kubectl get pod

NAME READY STATUS RESTARTS AGE

dapi-test-pod 0/1 ContainerCreating 0 3s

# 隔一段時間再查看pod,發現並沒有返回什麼

$ kubectl get pod

# 顯示所有的權限查看pod

$ kubectl get pod --show-all

NAME READY STATUS RESTARTS AGE

dapi-test-pod 0/1 Completed 0 1m

# 查看詳情

$ kubectl describe pod dapi-test-pod

Name: dapi-test-pod

Namespace: default

Node: 127.0.0.1/127.0.0.1

Start Time: Thu, 30 Nov 2017 15:32:00 +0800

Labels: <none>

Status: Succeeded

IP:

Controllers: <none>

Containers:

test-container:

Container ID: docker://1ba533f43ee60c02e03dafb7bcb8495fc12264aaab229872df0b289a3c1b9976

Image: nginx

Image ID: docker-pullable://docker.io/nginx@sha256:b81f317384d7388708a498555c28a7cce778a8f291d90021208b3eba3fe74887

Port:

Command:

/bin/sh

-c

env

State: Terminated

Reason: Completed

Exit Code: 0

Started: Thu, 30 Nov 2017 15:32:25 +0800

Finished: Thu, 30 Nov 2017 15:32:25 +0800

Ready: False

Restart Count: 0

Volume Mounts: <none>

Environment Variables:

SPECIAL_LEVEL_KEY: <set to the key 'special.how' of config map 'special-config'>

SPECIAL_TYPE_KEY: <set to the key 'special.type' of config map 'special-config'>

Conditions:

Type Status

Initialized True

Ready False

PodScheduled True

No volumes.

QoS Class: BestEffort

Tolerations: <none>

Events:

FirstSeen LastSeen Count From SubObjectPath Type Reason Message

--------- -------- ----- ---- ------------- -------- ------ -------

3m 3m 1 {default-scheduler } Normal Scheduled Successfully assigned dapi-test-pod to 127.0.0.1

3m 3m 1 {kubelet 127.0.0.1} spec.containers{test-container} Normal Pulling pulling image "nginx"

3m 2m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.

2m 2m 1 {kubelet 127.0.0.1} spec.containers{test-container} Normal Pulled Successfully pulled image "nginx"

2m 2m 1 {kubelet 127.0.0.1} spec.containers{test-container} Normal Created Created container with docker id 1ba533f43ee6; Security:[seccomp=unconfined]

2m 2m 1 {kubelet 127.0.0.1} spec.containers{test-container} Normal Started Started container with docker id 1ba533f43ee6

# 可知container started 成功，進一步查看日誌

$ docker logs 1ba

KUBERNETES_SERVICE_PORT=443

KUBERNETES_PORT=tcp://10.254.0.1:443

MY_SERVICE_PORT_80_TCP=tcp://10.254.110.249:80

MY_SERVICE_PORT_443_TCP_ADDR=10.254.110.249

HOSTNAME=dapi-test-pod

MY_SERVICE_PORT_443_TCP_PORT=443

HOME=/root

MY_SERVICE_PORT_443_TCP_PROTO=tcp

MY_SERVICE_SERVICE_PORT_HTTP=80

SPECIAL_TYPE_KEY=charm

MY_SERVICE_SERVICE_PORT_HTTPS=443

MY_SERVICE_PORT_443_TCP=tcp://10.254.110.249:443

MY_SERVICE_SERVICE_HOST=10.254.110.249

KUBERNETES_PORT_443_TCP_ADDR=10.254.0.1

NGINX_VERSION=1.13.7-1~stretch

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

KUBERNETES_PORT_443_TCP_PORT=443

NJS_VERSION=1.13.7.0.1.15-1~stretch

KUBERNETES_PORT_443_TCP_PROTO=tcp

MY_SERVICE_SERVICE_PORT=80

MY_SERVICE_PORT=tcp://10.254.110.249:80

SPECIAL_LEVEL_KEY=very

MY_SERVICE_PORT_80_TCP_ADDR=10.254.110.249

KUBERNETES_PORT_443_TCP=tcp://10.254.0.1:443

KUBERNETES_SERVICE_PORT_HTTPS=443

KUBERNETES_SERVICE_HOST=10.254.0.1

MY_SERVICE_PORT_80_TCP_PORT=80

PWD=/

MY_SERVICE_PORT_80_TCP_PROTO=tcp

ConfigMap的限制條件

ConfigMap必須在Pod之前創建才能被使用。
ConfigMap可以定義其屬於哪個Namspece，只有在同一個Namespace中的pod才能引用。

刪除Pod

有時候deployment、rs、rc、services都爲0，但是Pod確存在着。則重啓kubelet服務即可。

$ systemctl restart kubelet

補充

# 列出當前節點名

kubectl get node

NAME STATUS AGE

127.0.0.1 Ready 6d

# 已知當前節點名爲127.0.0.1,用如下命令即可獲得該節點上所有運行節點

$ curl localhost:8080/api/v1/proxy/nodes/127.0.0.1/pods

{"kind":"PodList","apiVersion":"v1","metadata":{},"items":null}

報錯

$ sudo kubectl create -f file.yaml

YAML error: found character that cannot start any token

# or

error:yaml: line 15: found a tab character that violate indentation

#file.yaml不可用tab鍵來空格

$ sudo kubectl create -f mysql-rc.yaml

error: error validating "mysql-rc.yaml": error validating data: [found invalid field app for v1.ObjectMeta, found invalid field value for v1.Container]; if you choose to ignore these errors, turn validation off with --validate=false

---------------------

# kubectl get pod --all-namespaces

NAMESPACE NAME READY STATUS RESTARTS AGE

default my-nginx-379829228-b796w 1/1 Running 0 12m

kube-system kubernetes-dashboard-2397086622-46tvx 0/1 ContainerCreating 0 8s

[root@node01 ~]# kubectl logs -f kubernetes-dashboard-2397086622-46tvx --namespace=kube-system

Using HTTP port: 9090

Using apiserver-host location: http://127.0.0.1:8080

Creating API server client for http://127.0.0.1:8080

Error while initializing connection to Kubernetes apiserver. This most likely means that the cluster is misconfigured (e.g., it has invalid apiserver certificates or service accounts configuration) or the --apiserver-host param points to a server that does not exist. Reason: Get http://127.0.0.1:8080/version: dial tcp 127.0.0.1:8080: getsockopt: connection refused

Refer to the troubleshooting guide for more information: https://github.com/kubernetes/dashboard/blob/master/docs/user-guide/troubleshooting.md

我們最好不要越過RC而直接創建Pod,因爲Replication Controller會通過RC管理Pod副本。實現自動創建、補足、替換、刪除Pod副本，大大提高系統的容災能力

重新調度(Rescheduling)
彈性伸縮(Scaling)
滾動更新(Rolling Updates)

本文轉自CSDN-k8s中文文檔

me的環境

kubernets單機版安裝部署

安裝流程，切換成root

修改兩處配置

啓動所有服務

初入門小實例

kubernets指令

對比docker命令

重要名詞

yaml文件管理服務

Service

deployments

deployment的更新回滾

ConfigMap-容器應用的配置管理

使用configMap替代環境變量

ConfigMap的限制條件

刪除Pod

補充

報錯

我們最好不要越過RC而直接創建Pod,因爲Replication Controller會通過RC管理Pod副本。實現自動創建、補足、替換、刪除Pod副本，大大提高系統的容災能力

再談23種設計模式（3）：行爲型模式（學習筆記）

Power Automate Desktop 安裝完，登錄後老是提示one driver 錯誤

微前端學習筆記(4):從微前端到微模塊之EMP與hel-micro方案探索

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