云原生|kubernetes|使用cri-docker部署基于kubeadm-1.25.4的集群

前言：

kubernetes的部署从1.24版本开始后，弃用docker-shim，也就是说部署1.24版本后的集群不能使用docker-ce了。

比较清晰的解决方案有两个，一是使用containerd，这个是一个新的支持cri标准的shim，一个是使用cri-docker这样的中间插件形式，一头通过CRI跟kubelet交互，另一头跟docker api交互，从而间接的实现了kubernetes以docker作为容器运行时。但是这种架构缺点也很明显，调用链更长，效率更低。

那么，cri-docker虽然有效率低下的缺点，但很明显这个更加符合原来的docker使用习惯。说人话就是部署简单，学习成本不会太高。

因此，如果是仅仅想测试新版本的kubernetes，体验新版本的kubernetes，无疑还是使用cri-docker更为合适的。

本文将就cri-docker的部署做一个详细的介绍，并基于cri-docker部署一个比较新的kubernetes集群。

实验目标：

利用kubeadm部署接近最新版本的kubernetes-1.25.4集群

实验环境：

一台VMware虚拟机，IP地址为：192.168.217.24

相关软件；

docker-ce-20.10.7

cri-docker-0.2.6

kubeadm-1.25.4

版本说明：

由于计划安装的kubernetes版本是比较新的，因此，三个软件的版本定的也都比较新。经过实际的测试，cri-docker和docker-ce的版本是有一定的对应关系的，前期使用docker-ce-19.0.3导致cri-docker无法安装，在这也提醒一下，最好使用以上的固定版本，否则会出各种意想不到的问题。

一，

docker-ce的安装

这个就没什么好说的，通常是有两种安装方式，一个是rpm方式，一个是二进制方式。

本文采用的是二进制安装方式，不需要配置yum源嘛，二进制部署的好处是可离线，部署方便快捷。

二进制安装包下载地址：

Index of linux/static/stable/x86_64/

下载下来的安装包上传到服务器后解压，并将解压后的目录下的所有文件拷贝到/usr/bin/目录下，这个没什么好说的，太基础就不写这了。

docker的配置文件：

cat >/etc/docker/daemon.json <<EOF
{
  "registry-mirrors": ["http://bc437cce.m.daocloud.io"],
  "exec-opts":["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2"
}
EOF

docker的启动脚本：

cat >/usr/lib/systemd/system/docker.service <<EOF 
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service containerd.service
Wants=network-online.target

[Service]
Type=notify
ExecStart=/usr/bin/dockerd --graph=/var/lib/docker
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
StartLimitBurst=3
StartLimitInterval=60s
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TasksMax=infinity
Delegate=yes
KillMode=process

[Install]
WantedBy=multi-user.target
EOF

启动docker服务：

systemctl enable docker && systemctl start docker

二，

cri-docker的安装部署

下载地址：

https://github.com/Mirantis/cri-dockerd/tags

cri-dockerd-0.2.6.amd64.tgz这个文件里就一个可执行文件，将此文件上传到服务器后，复制可执行文件到/usr/local/bin目录下，注意一定确保有执行权限：

[root@node4 ~]# ls -al /usr/local/bin/cri-dockerd 
-rwxr-xr-x 1 zsk zsk 52335229 Sep 25 10:44 /usr/local/bin/cri-dockerd

该服务的部署主要是两个启动脚本

1，

cri-docker的启动脚本

cat >/usr/lib/systemd/system/cri-docker.service <<EOF
[Unit]
Description=CRI Interface for Docker Application Container Engine
Documentation=https://docs.mirantis.com
After=network-online.target firewalld.service docker.service
Wants=network-online.target
Requires=cri-docker.socket
[Service]
Type=notify
ExecStart=/usr/local/bin/cri-dockerd --network-plugin=cni --pod-infra-container-image=registry.aliyuncs.com/google_containers/pause:3.7
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
StartLimitBurst=3
StartLimitInterval=60s
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TasksMax=infinity
Delegate=yes
KillMode=process
[Install]
WantedBy=multi-user.target
EOF

2，

cri-docker的socket

这个socket是与docker通信的关键服务，其中要注意，SocketGroup=root，有些人是写的SocketGroup=docker，这样的话此服务将不能启动。

cat >/usr/lib/systemd/system/cri-docker.socket <<
[Unit]
Description=CRI Docker Socket for the API
PartOf=cri-docker.service
[Socket]
ListenStream=%t/cri-dockerd.sock
SocketMode=0660
SocketUser=root
SocketGroup=root
[Install]
WantedBy=sockets.target
EOF

启动服务：

systemctl daemon-reload && systemctl enable cri-docker.socket
systemctl start cri-docker.socket cri-docker

稍微验证一哈：

可以看到一个active和两个绿色的running以及一个文件/var/run/cri-dockerd.sock表示服务没有问题。

[root@node4 ~]# systemctl is-active cri-docker.socket
active

[root@node4 ~]# systemctl status cri-docker cri-docker.socket
● cri-docker.service - CRI Interface for Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/cri-docker.service; enabled; vendor preset: disabled)
   Active: active (running) since Tue 2022-12-06 15:25:44 CST; 4h 27min ago
     Docs: https://docs.mirantis.com
 Main PID: 1256 (cri-dockerd)
   CGroup: /system.slice/cri-docker.service
           └─1256 /usr/local/bin/cri-dockerd --network-plugin=cni --pod-infra-container-image=registry.aliyuncs.com/google_containers/pause:3.7

Dec 06 19:52:22 node4 cri-dockerd[1256]: time="2022-12-06T19:52:22+08:00" level=info msg="Using CNI configuration file /etc/cni/net.d/10-flannel.conflist"
Dec 06 19:52:27 node4 cri-dockerd[1256]: time="2022-12-06T19:52:27+08:00" level=info msg="Using CNI configuration file /etc/cni/net.d/10-flannel.conflist"
Dec 06 19:52:32 node4 cri-dockerd[1256]: time="2022-12-06T19:52:32+08:00" level=info msg="Using CNI configuration file /etc/cni/net.d/10-flannel.conflist"
Dec 06 19:52:37 node4 cri-dockerd[1256]: time="2022-12-06T19:52:37+08:00" level=info msg="Using CNI configuration file /etc/cni/net.d/10-flannel.conflist"
Dec 06 19:52:42 node4 cri-dockerd[1256]: time="2022-12-06T19:52:42+08:00" level=info msg="Using CNI configuration file /etc/cni/net.d/10-flannel.conflist"
Dec 06 19:52:47 node4 cri-dockerd[1256]: time="2022-12-06T19:52:47+08:00" level=info msg="Using CNI configuration file /etc/cni/net.d/10-flannel.conflist"
Dec 06 19:52:52 node4 cri-dockerd[1256]: time="2022-12-06T19:52:52+08:00" level=info msg="Using CNI configuration file /etc/cni/net.d/10-flannel.conflist"
Dec 06 19:52:57 node4 cri-dockerd[1256]: time="2022-12-06T19:52:57+08:00" level=info msg="Using CNI configuration file /etc/cni/net.d/10-flannel.conflist"
Dec 06 19:53:02 node4 cri-dockerd[1256]: time="2022-12-06T19:53:02+08:00" level=info msg="Using CNI configuration file /etc/cni/net.d/10-flannel.conflist"
Dec 06 19:53:07 node4 cri-dockerd[1256]: time="2022-12-06T19:53:07+08:00" level=info msg="Using CNI configuration file /etc/cni/net.d/10-flannel.conflist"

● cri-docker.socket - CRI Docker Socket for the API
   Loaded: loaded (/usr/lib/systemd/system/cri-docker.socket; enabled; vendor preset: disabled)
   Active: active (running) since Tue 2022-12-06 15:25:30 CST; 4h 27min ago
   Listen: /run/cri-dockerd.sock (Stream)

Dec 06 15:25:30 node4 systemd[1]: Starting CRI Docker Socket for the API.
Dec 06 15:25:30 node4 systemd[1]: Listening on CRI Docker Socket for the API.

[root@node4 ~]# ls -al /var/run/cri-dockerd.sock
srwxr-xr-x 1 root root 0 Dec  6 15:25 /var/run/cri-dockerd.sock

三，

重新编译kubeadm

云原生|kubernetes|kubeadm部署的集群的100年证书_晚风_END的博客-CSDN博客

其中有编译好的kubeadm，可以直接从网盘下载，如果想自己动手，根据以上文章自行编译即可。

相关文件都放百度网盘里了：

链接：https://pan.baidu.com/s/1ondEDX4caJ16ic-R6cqy_A?pwd=star
提取码：star

四，

kubeadm初始化集群

安装阿里云的kubeadm，kubelet，kubectl

添加阿里云源：

cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

安装 kubeadm，kubelet，kubectl

yum install kubeadm-1.25.4 kubelet-1.25.4 kubectl-1.25.4 -y

替换第三步编译好的kubeadm，准备执行集群的初始化：

cp -a kubeadm-1.25.4 /usr/bin/kubeadm

初始化集群命令:

kubeadm init --image-repository registry.aliyuncs.com/google_containers --kubernetes-version=v1.25.4 --pod-network-cidr=10.244.0.0/16 --cri-socket /var/run/cri-dockerd.sock

部分输出的日志：

W1206 15:26:21.940820    2162 initconfiguration.go:119] Usage of CRI endpoints without URL scheme is deprecated and can cause kubelet errors in the future. Automatically prepending scheme "unix" to the "criSocket" with value "/var/run/cri-dockerd.sock". Please update your configuration!
[init] Using Kubernetes version: v1.25.4
[preflight] Running pre-flight checks
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local node4] and IPs [10.96.0.1 192.168.217.24]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [localhost node4] and IPs [192.168.217.24 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [localhost node4] and IPs [192.168.217.24 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
中间的略略略
To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 192.168.217.24:6443 --token bgkwcq.mgd8h263itfeiaia \
	--discovery-token-ca-cert-hash sha256:686af8c137f05a4f0051f8f7d03aabaa72d272b338430f19ca8aaf0d13745a2d

OK，maser节点这样就安装好了，工作节点加入的时候需要增加参数：

kubeadm join 192.168.217.24:6443 --token bgkwcq.mgd8h263itfeiaia \
	--discovery-token-ca-cert-hash sha256:686af8c137f05a4f0051f8f7d03aabaa72d272b338430f19ca8aaf0d13745a2d --cri-socket /var/run/cri-dockerd.sock

其它的都和低版本的kubernetes集群一样的了，只是需要注意一下，网络插件需要版本升高，例如flannel