kubeadm系列-00-overview

cat <<EOF | sudo tee /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-\$basearch
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
exclude=kubelet kubeadm kubectl
EOF

# 国内源也可以
cat <<EOF | sudo tee /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
       http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

# Set SELinux in permissive mode (effectively disabling it)
sudo setenforce 0
sudo sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config
# 关闭防火墙
systemctl stop firewalld && systemctl disable firewalld
sysctl -w net.ipv4.ip_forward=1
echo 1 > /proc/sys/net/bridge/bridge-nf-call-iptables
echo 1 > /proc/sys/net/ipv4/ip_forward
# 加载内核模块
modprobe br_netfilter
modprobe overlay
# 时间同步
yum install ntpdate -y
# 方便排查ipvs的问题
yum install -y ipset ipvsadm

# 安装1.24.1
sudo yum install -y kubelet-1.24.1-0 kubeadm-1.24.1-0 kubectl-1.24.1-0 --disableexcludes=kubernetes
# 安装1.21.7
sudo yum install -y kubelet-1.21.7-0 kubeadm-1.21.7-0 kubectl-1.21.7-0 --disableexcludes=kubernetes
# 删除1.24.1
sudo yum remove -y kubelet-1.24.1-0 kubeadm-1.24.1-0 kubectl-1.24.1-0 --disableexcludes=kubernetes
# 删除1.21.7
sudo yum remove -y kubelet-1.21.7-0 kubeadm-1.21.7-0 kubectl-1.21.7-0 --disableexcludes=kubernetes

cri-tools.x86_64 0:1.24.0-0                    
kubernetes-cni.x86_64 0:0.8.7-0                    
socat.x86_64 0:1.7.3.2-2.el7

cat /etc/systemd/system/multi-user.target.wants/kubelet.service
[Unit]
Description=kubelet: The Kubernetes Node Agent
Documentation=https://kubernetes.io/docs/
Wants=network-online.target
After=network-online.target

[Service]
ExecStart=/usr/bin/kubelet
Restart=always
StartLimitInterval=0
RestartSec=10

[Install]
WantedBy=multi-user.target

# 设置主机名
hostnamectl set-hostname master

kubeadm config images pull --kubernetes-version 1.24.1
# 用crictl下载
/usr/bin/crictl -r unix:///var/run/containerd/containerd.sock pull k8s.gcr.io/kube-apiserver:v1.24.1

# 必须更换两个endpoint，这个操作也可以直接修改kubeadm的初始化配置文件
crictl config runtime-endpoint unix:///run/containerd/containerd.sock
crictl config image-endpoint unix:///run/containerd/containerd.sock
# 测试一下
crictl pull docker.io/library/redis:alpine3.13
# 替换成国内的镜像

ctr --namespace k8s.io images list

journalctl -xeu containerd --no-page -f
journalctl -xeu kubelet --no-page -f

# 创建的k8s版本
[init] Using Kubernetes version: v1.24.1
# 从这里开始进入preflight的阶段
[preflight] Running pre-flight checks
	[WARNING SystemVerification]: missing optional cgroups: blkio
[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'
# 从这里进入证书的阶段
[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 [ip-172-31-90-126 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 172.31.90.126]
[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 [ip-172-31-90-126 localhost] and IPs [172.31.90.126 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [ip-172-31-90-126 localhost] and IPs [172.31.90.126 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
# 进入kubeconfig的阶段
[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
# 开始启动kubelet
[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
# 开始controlplane启动的阶段
[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"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[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
# 健康检查
[apiclient] All control plane components are healthy after 16.503764 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
# 给controlplane打上必要的label
[mark-control-plane] Marking the node ip-172-31-90-126 as control-plane by adding the labels: [node-role.kubernetes.io/control-plane node.kubernetes.io/exclude-from-external-load-balancers]
[mark-control-plane] Marking the node ip-172-31-90-126 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule node-role.kubernetes.io/control-plane:NoSchedule]
# 创建token
[bootstrap-token] Using token: qlk4br.83yi47aqacj3cwzh
[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
# 插件安装的阶段
[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

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 172.31.90.126:6443 --token qlk4br.83yi47aqacj3cwzh \
	--discovery-token-ca-cert-hash sha256:cc121a0e581abbdedcbad370077c46e11da9d6ea60a201dd54be4c70893f98f4