[k8s] 基于ubuntu22部署k8s1.28记录

k8s1.28部署已经不依赖docker了，所以不需要安装docker。同理：如果想查看镜像和运行容器，也不能用docker命令去查询了：需要使用crictl。不过crictl命令参数兼容docker，所以使用上手没有啥难度。

1. 配置安装源

根据k8s官方文档：https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/ 配置即可

apt-get install -y apt-transport-https ca-certificates curl
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.28/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
# This overwrites any existing configuration in /etc/apt/sources.list.d/kubernetes.list
echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.28/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
apt-get update
apt-get install -y kubelet kubeadm kubectl
apt-mark hold kubelet kubeadm kubectl

2. 主机系统参数配置

cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
overlay
br_netfilter
EOF

sudo modprobe overlay
sudo modprobe br_netfilter

# sysctl params required by setup, params persist across reboots
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables  = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.ipv4.ip_forward                 = 1
EOF

# Apply sysctl params without reboot
sudo sysctl --system

3. 修改containerd配置

k8s 1.24之前，还支持cri-dockerd ；1.24以及之后版本不再支持了。所以必须安装CRI-O或者containerd作为container runtime。这里我选择了containerd

containerd config default > /etc/containerd/config.toml

生成containerd配置文件，然后/etc/containerd/config.toml中修改如下配置项：

a. 修改SystemdCgroup

[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
  ...
  [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
    SystemdCgroup = true

b. 修改pause镜像路径

[plugins."io.containerd.grpc.v1.cri"]
  #sandbox_image = "registry.k8s.io/pause:3.2"
  sandbox_image = "registry.aliyuncs.com/google_containers/pause:3.9"

你要是有魔法能从registry.k8s.io拉下来镜像，这b步骤不改也行

最后重启containerd服务

systemctl restart containerd

4. 生成kubeadm配置文件

kubeadm config print init-defaults > kubeadm-config.yaml

编辑kubeadm-config.yaml文件，修改advertiseAddress和主机name，替换镜像仓库地址，增加podSubnet：

localAPIEndpoint:
  advertiseAddress: 本机IP
  bindPort: 6443
nodeRegistration:
  criSocket: unix:///var/run/containerd/containerd.sock
  imagePullPolicy: IfNotPresent
  name: 替换成hostname

imageRepository: registry.aliyuncs.com/google_containers
....
networking:
....
  podSubnet: 10.244.0.0/16

5. 部署k8s

 kubeadm init --config kubeadm-config.yaml

如果顺利，应该几分钟就ok了

6. 部署flannel

kubectl apply -f https://github.com/flannel-io/flannel/releases/latest/download/kube-flannel.yml

测试结果flannel镜像是docker.io拉取，可以直接拉，不需要做国内源替换。但是这边记录一个坑：flannel已经running得情况下，coredns依然是pending状态。 这边参考了一篇博客解决这个问题：https://discuss.kubernetes.io/t/k8s-cni-plugin-issue-cni-plugin-not-initialized-while-kube-flannel-is-running/24136

总结就是：reboot
实践证明，可行