wsl2 ubuntu20.04 上使用 kubeadm 创建一个单主集群
环境初始化
- 建议尽可能初始化环境,命令
wsl --unregister Ubuntu-20.04
可重新安装,相当于重装系统。安装或重置过程中,打开这个 wsl2 窗口,提示如下:
Installing, this may take a few minutes...
适用于 Linux 的 Windows 子系统实例已终止。
Please create a default UNIX user account. The username does not need to match your Windows username.
For more information visit: https://aka.ms/wslusers
Enter new UNIX username:
- 此时关掉窗口再打开,以后则默认使用 root 用户登录。
- 使用阿里镜像:
sudo cat <<EOF >/etc/apt/sources.list
deb http://mirrors.aliyun.com/ubuntu/ $(lsb_release -cs) main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ $(lsb_release -cs) main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ $(lsb_release -cs)-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ $(lsb_release -cs)-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ $(lsb_release -cs)-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ $(lsb_release -cs)-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ $(lsb_release -cs)-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ $(lsb_release -cs)-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ $(lsb_release -cs)-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ $(lsb_release -cs)-backports main restricted universe multiverse
EOF
- 更新缓存
sudo apt update
wsl2 官方 ubuntu 系统启动方式为 init,而 k8s 安装过程需要系统以 systemd 方式启动。查询 docker 状态的源码,可以看到是通过
systemctl is-active docker
查询,因此要想办法在 wsl2 启用 systemd。参考Using snapd in WSL2可知: Systemd 已经预安装,但并未激活。使用方式很简单,就是将它放到一个“容器”,在该容器里,Systemd 的 pid 是 1。命令如下:
安装
daemonize
sudo apt install daemonize
sudo daemonize /usr/bin/unshare --fork --pid --mount-proc /lib/systemd/systemd --system-unit=basic.target
- 使用命令
ps -aux
查看进程 pid。使用以下命令进入这个“容器”,在此查看进程 pid,可以看到 pid 为 1 的进程变成了 systemd。使用命令stat /proc/1/exe
亦可验证。
exec sudo nsenter -t $(pidof systemd) -a su - $LOGNAME
安装 Docker
- 安装命令,参考安装 Docker。
# 安装 Docker CE
## 设置仓库
### 安装软件包以允许 apt 通过 HTTPS 使用存储库
apt-get update && apt-get install \
apt-transport-https ca-certificates curl software-properties-common
### 新增 Docker 的 官方 GPG 秘钥
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -
### 添加 Docker apt 仓库
add-apt-repository \
"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) \
stable"
## 安装 Docker CE
apt-get update && apt-get install \
containerd.io \
docker-ce \
docker-ce-cli -y
# 设置 daemon
cat > /etc/docker/daemon.json <<EOF
{
"registry-mirrors": ["https://registry.docker-cn.com"],
"exec-opts": ["native.cgroupdriver=systemd"],
"log-driver": "json-file",
"log-opts": {
"max-size": "100m"
},
"storage-driver": "overlay2"
}
EOF
mkdir -p /etc/systemd/system/docker.service.d
# 重启 docker.
systemctl daemon-reload
systemctl restart docker
- 其它资料:
安装 kubelet、kubeadm、kubectl
- 官方文档安装 kubeadm、kubelet 和 kubectl
- 官方 GPG 秘钥无法访问,按照阿里云 Kubernetes 镜像配置,设置一下安装源然后开始安装 kubelet、kubeadm、kubectl。因为还没 ubuntu20.04 还没有相应源,先用 ubuntu18.04 的。
apt-get update && apt-get install -y apt-transport-https
curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | apt-key add -
cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main
EOF
apt-get update
apt-get install -y kubelet kubeadm kubectl
使用 kubeadm 创建单个控制平面集群
插件列表参考文档安装扩展
污点和容忍: Taint 和 Toleration
初始化命令:
kubeadm init --pod-network-cidr=10.244.0.0/16 --control-plane-endpoint=ubuntu.wsl --image-repository=gotok8s --v=5
- 其中 pod-network-cidr 指定网络驱动的 CIDR,根据使用的插件而定。这里使用 flannel,文档指示使用值
10.244.0.0/16
。 - control-plane-endpoint 指定主节点地址,可以是 IP 地址或者是可以映射 ip 地址的 DNS 名称。因此使用前要设置一下:
cat <<EOF >>/etc/hosts $(ip address | grep eth0 | grep inet | awk -F ' ' '{ print $2}' | awk -F / '{ print $1}') ubuntu.wsl EOF
- image-repository 指定拉取镜像的仓库,gotok8s是 docker hub 上的用户,同步了安装所需镜像,否则国内会因访问不了 gcr.io 而安装失败。
--v=5
是调试选项,加上后可看到更详细输出。
- 其中 pod-network-cidr 指定网络驱动的 CIDR,根据使用的插件而定。这里使用 flannel,文档指示使用值
root@DESKTOP-QNMROJ1:~# kubeadm init --pod-network-cidr=10.244.0.0/16 --control-plane-endpoint=ubuntu.wsl --image-repository=gotok8s
W0706 21:45:49.154779 1903997 version.go:102] could not fetch a Kubernetes version from the internet: unable to get URL "https://dl.k8s.io/release/stable-1.txt": Get https://dl.k8s.io/release/stable-1.txt: dial tcp: lookup dl.k8s.io on 127.0.0.53:53: server misbehaving
W0706 21:45:49.154839 1903997 version.go:103] falling back to the local client version: v1.18.5
W0706 21:45:49.155372 1903997 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
[init] Using Kubernetes version: v1.18.5
[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'
[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
[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 [desktop-qnmroj1 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local ubuntu.wsl] and IPs [10.96.0.1 172.25.14.224]
[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 [desktop-qnmroj1 localhost] and IPs [172.25.14.224 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [desktop-qnmroj1 localhost] and IPs [172.25.14.224 127.0.0.1 ::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
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
W0706 21:45:54.052056 1903997 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[control-plane] Creating static Pod manifest for "kube-scheduler"
W0706 21:45:54.053414 1903997 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[apiclient] All control plane components are healthy after 33.002925 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.18" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node desktop-qnmroj1 as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node desktop-qnmroj1 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: 8328sm.dh21due3jz2okibj
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
Your Kubernetes control-plane has initialized successfully!
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
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/
You can now join any number of control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:
kubeadm join ubuntu.wsl:6443 --token 8328sm.dh21due3jz2okibj \
--discovery-token-ca-cert-hash sha256:31f44da2c275026d9d71ddcd138f8c6a5ac4fecbc167d8b6247788f9651afa53 \
--control-plane
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join ubuntu.wsl:6443 --token 8328sm.dh21due3jz2okibj \
--discovery-token-ca-cert-hash sha256:31f44da2c275026d9d71ddcd138f8c6a5ac4fecbc167d8b6247788f9651afa53
- 配置 cluster 信息使 kubectl 可用
# 非 root 用户执行下面命令
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
# root用户可执行如下命令
export KUBECONFIG=/etc/kubernetes/admin.conf
- 安装网络插件
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
- 控制平面节点隔离。默认情况下,出于安全原因,群集不会在控制平面节点上调度 Pod。如果希望能够在控制平面节点上安排 Pod,例如对于用于开发的单机 Kubernetes 群集,请运行:
kubectl taint nodes --all node-role.kubernetes.io/master-
- 运行 nginx 测试。如果遇到
Temporary failure in name resolution
这种访问的问题,请打开非 systemd 空间的控制台操作。
kubectl run nginx --image=nginx --port=80 --hostport=80
curl 127.0.0.1
- 监控集群状态,大概每两秒刷新一次。
watch kubectl get all -A