前言
Kubernetes 要在 v1.20 开始弃用 docker 了 ？其实是弃用 kubelet 中集成的 dockershim 模块, 也就是说不再将 docker 作为默认的 container runtime，不过应该还是可以通过外接方式使用docker的。感兴趣的同学可以通过以下链接了解个中缘由。
https://kubernetes.io/blog/2020/12/02/dockershim-faq
https://kubernetes.io/blog/2020/12/02/dont-panic-kubernetes-and-docker
这里先不讨论 docker， 主要记录如何使用除 docker 之外的其它 container runtime 部署 kubernetes 集群。值得注意的是，只有符合 CRI（Container Runtime Interface）标准的 container runtime 才可以对接 kubernetes。
本文主要介绍如何使用以下三种cri-runtime部署kubernetes集群：
集群部署
首先部署container-runtime，containerd、cri-o、isula任选其一，注意集群中所有节点container-runtime应保持一致。
部署contaner-runtime
containerd
# 1. 安装 runc
curl -OL https://github.com/opencontainers/runc/releases/download/v1.0.0-rc92/runc.amd64
mv runc.amd64 /usr/local/bin/runc && chmod +x /usr/local/bin/runc
# 2. 安装 containerd
curl -OL https://github.com/containerd/containerd/releases/download/v1.4.3/containerd-1.4.3-linux-amd64.tar.gz
tar -zxvf containerd-1.4.3-linux-amd64.tar.gz -C /usr/local
curl -o /etc/systemd/system/containerd.service https://raw.githubusercontent.com/containerd/cri/master/contrib/systemd-units/containerd.service
# 3. 配置 containerd
mkdir -p /etc/containerd
cat > /etc/containerd/config.toml << EOF
[plugins]
[plugins."io.containerd.grpc.v1.cri"]
sandbox_image = "kubesphere/pause:3.2"
[plugins."io.containerd.grpc.v1.cri".registry]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors."docker.io"]
endpoint = ["https://registry-1.docker.io"] ## 这里可替换成dockerhub的镜像加速器
EOF
systemctl enable containerd && systemctl restart containerd
# 4. 安装 crictl
VERSION="v1.19.0"
curl -OL https://github.com/kubernetes-sigs/cri-tools/releases/download/$VERSION/crictl-$VERSION-linux-amd64.tar.gz
sudo tar zxvf crictl-$VERSION-linux-amd64.tar.gz -C /usr/local/bin
rm -f crictl-$VERSION-linux-amd64.tar.gz
# 5. 配置crictl
cat > /etc/crictl.yaml << EOF
runtime-endpoint: unix:///run/containerd/containerd.sock
image-endpoint: unix:///run/containerd/containerd.sock
timeout: 2
debug: false
pull-image-on-create: false
EOF
cri-o
# 1. 安装cri-o
yum install git make
curl -OL https://github.com/cri-o/cri-o/releases/download/v1.18.4/crio-v1.18.4.tar.gz
tar -zxf crio-v1.18.4.tar.gz
cd crio-v1.18.4
mkdir -p /etc/crio /opt/cni/bin /usr/local/share/oci-umount/oci-umount.d /usr/local/lib/systemd/system
make install
echo "fs.may_detach_mounts=1" >> /etc/sysctl.conf
sysctl -p
# 2. 配置cri-o
vi /etc/crio/crio.conf
# 找到如下参数进行修改
pause_image = "kubesphere/pause:3.2"
registries = [
"docker.io" ## 这里可替换成dockerhub的镜像加速器
]
# 3. 启动crio
systemctl enable crio && systemctl restart crio
isula （操作系统使用 openEuler 20.09）
# 1. 安装isula
yum install iSulad -y
# 2. 配置isula
vim /etc/isulad/daemon.json
# 对如下参数进行修改
"registry-mirrors": [
"docker.io" ## 这里可替换成dockerhub的镜像加速器
]
"pod-sandbox-image": "kubesphere/pause:3.2"
"network-plugin": "cni"
"cni-bin-dir": "/opt/cni/bin"
"cni-conf-dir": "/etc/cni/net.d"
# 3. 启动isula
systemctl enable isulad && systemctl restart isulad
部署kubernetes
这里使用kubekey来部署kubernetes集群。
# 1. 下载kubekey
## 这里暂时使用kubekey v1.1.0-alpha.1部署kubernetes集群，该版本为预览版，支持多container-runtime也会包含在后续的正式版本中。
curl -OL https://github.com/kubesphere/kubekey/releases/download/v1.1.0-alpha.1/kubekey-v1.1.0-alpha.1-linux-amd64.tar.gz
tar -zxvf kubekey-v1.1.0-alpha.1-linux-amd64.tar.gz
# 2. 创建配置文件
./kk create config # 默认在同级目录下生成 config-sample.yaml
# 3. 根据真实环境信息修改配置文件
vi config-sample.yaml
apiVersion: kubekey.kubesphere.io/v1alpha1
kind: Cluster
metadata:
name: sample
spec:
hosts:
- {name: node1, address: 192.168.6.3, internalAddress: 192.168.6.3, password: xxx}
- {name: node2, address: 192.168.6.4, internalAddress: 192.168.6.4, password: xxx}
roleGroups:
etcd:
- node1
master:
- node1
worker:
- node1
- node2
controlPlaneEndpoint:
domain: lb.kubesphere.local
address: ""
port: 6443
kubernetes:
version: v1.17.9
imageRepo: kubesphere
clusterName: cluster.local
containerManager: containerd ## 这里填入之前部署的container-runtime：containerd / crio / isula
network:
plugin: calico
kubePodsCIDR: 10.233.64.0/18
kubeServiceCIDR: 10.233.0.0/18
registry:
registryMirrors: []
insecureRegistries: []
addons: []
# 4. 部署集群
./kk create cluster -f config-sample.yaml --with-kubesphere
# 5. 等待集群部署完成
查看部署结果
可登录kubesphere控制台查看集群节点所使用的container-runtime
containerd
crio
isula
