kubernetes高可用集群搭建

服务器规划

注意：使用kube-vip管理vip需要保证vip和节点ip在同一子网中

安装kubeadm、kubelet、kubectl

将以下内容copy到一个脚本文件中，然后ansible copy到所有节点，最后ansible执行脚本，从而完成kubeadm、kubelet、kubectl的安装

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

cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sudo sysctl —system

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=1
repo_gpgcheck=1
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


# Set SELinux in permissive mode (effectively disabling it)
sudo setenforce 0
sudo sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

sudo yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes

sudo systemctl enable --now kubelet

准备kube-vip相关配置和static-pod.yaml

在三个master节点上创建文件 /etc/kube-vip/config.yaml

master1

localPeer:
  id: master1
  address: 172.16.27.10
  port: 10000
remotePeers:
  - id: master2
    address: 172.16.27.11
    port: 10000
  - id: master3
    address: 172.16.27.12
    port: 10000
vip: 172.16.27.20
gratuitousARP: true
singleNode: false
startAsLeader: true
interface: ens33
loadBalancers:
  - name: API Server Load Balancer
    type: tcp
    port: 8443
    bindToVip: false
    backends:
      - port: 6443
        address: 172.16.27.10
      - port: 6443
        address: 172.16.27.11
      - port: 6443
        address: 172.16.27.12

master2

localPeer:
  id: master2
  address: 172.16.27.11
  port: 10000
remotePeers:
  - id: master1
    address: 172.16.27.10
    port: 10000
  - id: master3
    address: 172.16.27.12
    port: 10000
vip: 172.16.27.20
gratuitousARP: true
singleNode: false
startAsLeader: true
interface: ens33
loadBalancers:
  - name: API Server Load Balancer
    type: tcp
    port: 8443
    bindToVip: false
    backends:
      - port: 6443
        address: 172.16.27.10
      - port: 6443
        address: 172.16.27.11
      - port: 6443
        address: 172.16.27.12

master3

localPeer:
  id: master3
  address: 172.16.27.12
  port: 10000
remotePeers:
  - id: master1
    address: 172.16.27.10
    port: 10000
  - id: master2
    address: 172.16.27.11
    port: 10000
vip: 172.16.27.20
gratuitousARP: true
singleNode: false
startAsLeader: true
interface: ens33
loadBalancers:
  - name: API Server Load Balancer
    type: tcp
    port: 8443
    bindToVip: false
    backends:
      - port: 6443
        address: 172.16.27.10
      - port: 6443
        address: 172.16.27.11
      - port: 6443
        address: 172.16.27.12

首先在master上创建/etc/kubernetes/manifests/kube-vip.yaml

apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  name: kube-vip
  namespace: kube-system
spec:
  containers:
  - command:
    - /kube-vip
    - start
    - -c
    - /vip.yaml
    image: 'plndr/kube-vip:0.1.1'
    name: kube-vip
    resources: {}
    securityContext:
      capabilities:
        add:
        - NET_ADMIN
        - SYS_TIME
    volumeMounts:
    - mountPath: /vip.yaml
      name: config
  hostNetwork: true
  volumes:
  - hostPath:
      path: /etc/kube-vip/config.yaml
    name: config
status: {}

安装集群

使用flannel指定对对应--pod-network-cidr=10.244.0.0/16

kubeadm init --pod-network-cidr=10.244.0.0/16  --control-plane-endpoint="172.16.27.20:8443"  --upload-certs

使用calico指定对对应--pod-network-cidr=192.168.0.0/16

kubeadm init --pod-network-cidr=192.168.0.0/16  --control-plane-endpoint="172.16.27.20:8443"  --upload-certs

保证kube-vip的高可用

ansible复制master1上的/etc/kubernetes/manifests/kube-vip.yaml到master2、master3