Kubernetes实战(三十一)-安装containerd

1 资源

containerd项目官方地址

GitHub - containerd/containerd: An open and reliable container runtime

containerd的发布版本地址：

Releases · containerd/containerd · GitHub

2 安装containerd

2.1 解压安装

2.1.1 下载压缩包

curl -LO https://github.com/containerd/containerd/releases/download/v1.6.6/containerd-1.6.6-linux-amd64.tar.gz

2.1.2 解压

解压到/usr/local目录下

tar Cxzvf /usr/local containerd-1.6.6-linux-amd64.tar.gz

解压完成后，执行ctr -v 或者ctr version便可查看版本

2.1.3 配置成systemd任务

mkdir -p /usr/local/lib/systemd/system/ && \
curl -L https://raw.githubusercontent.com/containerd/containerd/main/containerd.service -o /usr/local/lib/systemd/system/containerd.service && \
systemctl daemon-reload && \
systemctl enable --now containerd

2.1.4 安装runc

runc是容器运行时，runc实现了容器的init，run，create，ps...我们在运行容器所需要的cmd

curl -LO https://github.com/opencontainers/runc/releases/download/v1.1.1/runc.amd64 && \
install -m 755 runc.amd64 /usr/local/sbin/runc

2.1.5 安装cni

CNI(Container Network Interface) 是一套容器网络接口规范，通过插件的形式支持各种各样的网络类型，而标准化的好处就是你只需一套标准json配置就可以为一个容器创建网络接口。

curl -JLO https://github.com/containernetworking/plugins/releases/download/v1.1.1/cni-plugins-linux-amd64-v1.1.1.tgz
mkdir -p /opt/cni/bin && \
tar Cxzvf /opt/cni/bin cni-plugins-linux-amd64-v1.1.1.tgz

经过上面的步骤，把cni插件的可执行文件安装到了/opt/cni/bin目录下

2.1.6 配置containerd镜像源

由于网络原因，无法直接访问k8s.gcr.io网站。因此需要修改containerd的配置文件config.toml配置一下containerd的镜像源

mkdir -p /etc/containerd && \
containerd config default > /etc/containerd/config.toml && \
sed -i "s#k8s.gcr.io/pause#registry.aliyuncs.com/google_containers/pause#g"  /etc/containerd/config.toml  && \
sed -i 's#SystemdCgroup = false#SystemdCgroup = true#g' /etc/containerd/config.toml  && \
sed -i '/registry.mirrors]/a\ \ \ \ \ \ \ \ [plugins."io.containerd.grpc.v1.cri".registry.mirrors."docker.io"]' /etc/containerd/config.toml  && \
sed -i '/registry.mirrors."docker.io"]/a\ \ \ \ \ \ \ \ \ \ endpoint = ["http://hub-mirror.c.163.com"]' /etc/containerd/config.toml && \
sed -i '/hub-mirror.c.163.com"]/a\ \ \ \ \ \ \ \ [plugins."io.containerd.grpc.v1.cri".registry.mirrors."k8s.gcr.io"]' /etc/containerd/config.toml  && \
sed -i '/"k8s.gcr.io"]/a\ \ \ \ \ \ \ \ \ \ endpoint = ["http://registry.aliyuncs.com/google_containers"]' /etc/containerd/config.toml && \
echo "===========restart containerd to reload config===========" && \
systemctl restart containerd

3 containerd基本使用

containerd命令与docker的命令大同小异，只是containerd多了一个namespace的概念。

ctr help可以查看containerd的命令

查看namespace为baiyu下的镜像文件

ctr images ls ns baiyu

一般k8s的镜像都会下载在k8s.io这个命名空间下

ctr iamges ls ns k8s.io

至此，k8s的基础容器containerd环境已经安装完毕了。

注意，containerd是每台节点机器都要进行安装的。

4 nerdctl工具安装及使用

nerdctl工具，是containerd官方为了让docker用户无感切换到containerd而开发的命令行工具。也就是docker的命令可以直接在nerdctl上使用

nerdctl地址：containerd/nerdctl首页 - GitCode

curl -LO https://github.com/containerd/nerdctl/releases/download/v0.22.2/nerdctl-0.22.2-linux-amd64.tar.gz
tar xzvf nerdctl-0.22.2-linux-amd64.tar.gz
cp nerdctl /usr/local/bin/
rm -rf containerd-rootless* nerdctl

5 安装脚本

#!/bin/bash
echo "===========Installing containerd to /user/local===========" && \
tar Cxzvf /usr/local containerd-1.6.6-linux-amd64.tar.gz && \
mkdir -p /usr/local/lib/systemd/system/ && \
echo "===========start containerd via systemd===========" && \
curl -L https://raw.githubusercontent.com/containerd/containerd/main/containerd.service -o /usr/local/lib/systemd/system/containerd.service && \
systemctl daemon-reload && \
systemctl enable --now containerdecho "===========install runc.amd64 to /usr/local/sbin/runc==========="
curl -LO https://github.com/opencontainers/runc/releases/download/v1.1.4/runc.amd64 && \
install -m 755 runc.amd64 /usr/local/sbin/runcecho "===========install cni==========="
mkdir -p /opt/cni/bin && \
tar Cxzvf /opt/cni/bin cni-plugins-linux-amd64-v1.1.1.tgzecho "===========generate containerd config==========="
mkdir -p /etc/containerd && \
containerd config default > /etc/containerd/config.toml && \
sed -i "s#k8s.gcr.io/pause#registry.aliyuncs.com/google_containers/pause#g"  /etc/containerd/config.toml  && \
sed -i 's#SystemdCgroup = false#SystemdCgroup = true#g' /etc/containerd/config.toml  && \
sed -i '/registry.mirrors]/a\ \ \ \ \ \ \ \ [plugins."io.containerd.grpc.v1.cri".registry.mirrors."docker.io"]' /etc/containerd/config.toml  && \
sed -i '/registry.mirrors."docker.io"]/a\ \ \ \ \ \ \ \ \ \ endpoint = ["http://hub-mirror.c.163.com"]' /etc/containerd/config.toml && \
sed -i '/hub-mirror.c.163.com"]/a\ \ \ \ \ \ \ \ [plugins."io.containerd.grpc.v1.cri".registry.mirrors."k8s.gcr.io"]' /etc/containerd/config.toml  && \
sed -i '/"k8s.gcr.io"]/a\ \ \ \ \ \ \ \ \ \ endpoint = ["http://registry.aliyuncs.com/google_containers"]' /etc/containerd/config.toml && \
echo "===========restart containerd to reload config===========" && \
systemctl restart containerd