CentOS8 安裝Containerd.io

安裝Containerd.io

1、Containerd.io 要求 CentOS 系統的內核版本高於 3.10 ，查看本頁面的前提條件來驗證你的CentOS 版本是否支持 Containerd.io 。

通過 **uname -r **命令查看你當前的內核版本

[root@k8s-master ~]# uname -r
4.18.0-80.el8.x86_64

2、使用 root 權限登錄 Centos。確保 yum 包更新到最新。

[root@k8s-master ~]# yum updateRepository AppStream is listed more than once in the configuration
Repository BaseOS is listed more than once in the configuration
Repository extras is listed more than once in the configuration
Repository PowerTools is listed more than once in the configuration
Repository centosplus is listed more than once in the configuration
Last metadata expiration check: 0:09:18 ago on Fri 25 Dec 2020 09:04:58 PM CST.
Dependencies resolved.
Nothing to do.
Complete!
[root@k8s-master ~]# 

3、爲了解決 podman  衝突的問題 ，可以先執行如下命令：

[root@k8s-master ~]# yum erase podman buildah -y

4、安裝containerd.io

[root@k8s-master ~]# yum install https://download.docker.com/linux/centos/8/x86_64/stable/Packages/containerd.io-1.4.9-3.1.el8.x86_64.rpm -y

⚠️此命令可能由於下載超時無法安裝，可以先本地下載好安裝包，進行離線安裝，命令 yum install containerd.io-1.4.9-3.1.el8.x86_64.rpm -y

5、生成默認配置，並修改默認鏡像地址

[root@k8s-master ~]# cd /etc/containerd
[root@k8s-master ~]# ls
config.toml
[root@k8s-master ~]# containerd config default | tee config.toml
..........
............

# 重啓 containerd
[root@k8s-master ~]# systemctl restart containerd
Failed to restart containerd.service: Access denied
See system logs and 'systemctl status containerd.service' for details.

# 如果出現上面的錯誤，則執行如下命令
[root@k8s-master ~]# kill -TERM 1

# 然後再次執行重啓
[root@k8s-master ~]# systemctl restart containerd

使用 systemdcgroup 驅動程序

結合runc使用systemdcgroup 驅動，在/etc/containerd/config.toml中設置

[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
  ...
  [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
    SystemdCgroup = true
    endpoint = ["https://gj9l74ds.mirror.aliyuncs.com"]

如果您應用此更改，請確保再次重新啓動 containerd：

systemctl restart containerd

6、運行命令並驗證

containerd 相比於docker , 多了namespace概念, 每個image和container 都會在各自的namespace下可見, 目前k8s會使用k8s.io 作爲命名空間：ctr ns ls 可以查看命名空間

ctr 是containerd 提供的命令行工具，更多命令說明請執行：ctr -h

[root@k8s-master ~]# ctr -h
NAME:
   ctr - 
        __
  _____/ /______
 / ___/ __/ ___/
/ /__/ /_/ /
\___/\__/_/

containerd CLI


USAGE:
   ctr [global options] command [command options] [arguments...]

VERSION:
   1.4.9

DESCRIPTION:
   
ctr is an unsupported debug and administrative client for interacting
with the containerd daemon. Because it is unsupported, the commands,
options, and operations are not guaranteed to be backward compatible or
stable from release to release of the containerd project.

COMMANDS:
   plugins, plugin            provides information about containerd plugins
   version                    print the client and server versions
   containers, c, container   manage containers
   content                    manage content
   events, event              display containerd events
   images, image, i           manage images
   leases                     manage leases
   namespaces, namespace, ns  manage namespaces
   pprof                      provide golang pprof outputs for containerd
   run                        run a container
   snapshots, snapshot        manage snapshots
   tasks, t, task             manage tasks
   install                    install a new package
   oci                        OCI tools
   shim                       interact with a shim directly
   help, h                    Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --debug                      enable debug output in logs
   --address value, -a value    address for containerd's GRPC server (default: "/run/containerd/containerd.sock") [$CONTAINERD_ADDRESS]
   --timeout value              total timeout for ctr commands (default: 0s)
   --connect-timeout value      timeout for connecting to containerd (default: 0s)
   --namespace value, -n value  namespace to use with commands (default: "default") [$CONTAINERD_NAMESPACE]
   --help, -h                   show help
   --version, -v                print the version
[root@k8s-master ~]#