Centos7使用kubeadm 安装多主高可用kubernets:v.1.11集群

实验环境介绍：

本次实验环境是5个节点 3台master 2台node节点：

k8smaster01 192.168.111.128 软件：etcd k8smaster haproxy keepalived
k8smaster02 192.168.111.129 软件：etcd k8smaster haproxy keepalived
k8smaster03 192.168.111.130 软件：etcd k8smaster haproxy keepalived
k8snode01 192.168.111.131  软件：k8snode
k8snode02 192.168.111.132  软件：k8snode

VIP： 192.168.111.100

系统优化（在所有节点上操作）

关闭防火墙

systemctl stop firewalld.service
systemctl disable firewalld.service

关闭SELINUX和swap，优化内核参数

 sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
 setenforce 0

 # 临时关闭swap
 # 永久关闭 注释/etc/fstab文件里swap相关的行
 swapoff -a

# 配置转发相关参数，否则可能会出错
cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
vm.swappiness=0
EOF
sysctl --system

# 加载ipvs相关内核模块
# 如果重新开机，需要重新加载
modprobe ip_vs
modprobe ip_vs_rr
modprobe ip_vs_wrr
modprobe ip_vs_sh
modprobe nf_conntrack_ipv4
lsmod | grep ip_vs

配置yum源

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
mv /etc/yum.repos.d/epel.repo /etc/yum.repos.d/epel.repo.backup
mv /etc/yum.repos.d/epel-testing.repo /etc/yum.repos.d/epel-testing.repo.backup
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

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

yum clean all && yum makecache 

sudo yum install -y yum-utils device-mapper-persistent-data lvm2

配置hosts解析

192.168.111.128 k8smaster01
192.168.111.129 k8smaster02
192.168.111.130 k8smaster03
192.168.111.131 k8snode01
192.168.111.132 k8snode02

安装docker

v1.11.1版本推荐使用docker v17.03,v1.11,v1.12,v1.13, 也可以使用，再高版本官网不推荐使用，但是可以忽略。

这里安装18.06.0-ce

yum -y install docker-ce
systemctl enable docker && systemctl restart docker

安装 kubeadm, kubelet 和 kubectl(所有节点)

yum install -y kubelet kubeadm kubectl ipvsadm
systemctl enable kubelet && systemctl start kubelet

 配置haproxy代理和keepalived（如下操作在所有master节点上操作）

# 拉取haproxy镜像
docker pull haproxy:1.7.8-alpine
cat >/etc/haproxy/haproxy.cfg<<EOF
global
  log 127.0.0.1 local0 err
  maxconn 5000
  uid 99
  gid 99
  #daemon
  nbproc 1
  pidfile haproxy.pid

defaults
  mode http
  log 127.0.0.1 local0 err
  maxconn 5000
  retries 3
  timeout connect 5s
  timeout client 30s
  timeout server 30s
  timeout check 2s

listen admin_stats
  mode http
  bind 0.0.0.0:1080
  log 127.0.0.1 local0 err
  stats refresh 30s
  stats uri     /haproxy-status
  stats realm   Haproxy\ Statistics
  stats auth    will:will
  stats hide-version
  stats admin if TRUE

frontend k8s-https
  bind 0.0.0.0:8443
  mode tcp
  #maxconn 50000
  default_backend k8s-https

backend k8s-https
  mode tcp
  balance roundrobin
  server k8smaster01 192.168.111.128:6443 weight 1 maxconn 1000 check inter 2000 rise 2 fall 3
  server k8smaster02 192.168.111.129:6443 weight 1 maxconn 1000 check inter 2000 rise 2 fall 3
  server k8smaster03 192.168.111.130:6443 weight 1 maxconn 1000 check inter 2000 rise 2 fall 3
EOF
# 启动haproxy
docker run -d --name my-haproxy \
-v /etc/haproxy:/usr/local/etc/haproxy:ro \
-p 8443:8443 \
-p 1080:1080 \
--restart always \
haproxy:1.7.8-alpine
# 拉取keepalived镜像
docker pull osixia/keepalived:1.4.4

# 启动
# 载入内核相关模块
lsmod | grep ip_vs
modprobe ip_vs

# 启动keepalived
# ens33为本次实验192.168.111.0/24网段的所在网卡
docker run --net=host --cap-add=NET_ADMIN \
-e KEEPALIVED_INTERFACE=ens33 \
-e KEEPALIVED_VIRTUAL_IPS="#PYTHON2BASH:['192.168.111.100']" \
-e KEEPALIVED_UNICAST_PEERS="#PYTHON2BASH:['192.168.111.128','192.168.111.129','192.168.111.130']" \
-e KEEPALIVED_PASSWORD=hello \
--name k8s-keepalived \
--restart always \
-d osixia/keepalived:1.4.4

# 此时会配置 192.168.111.100 到其中一台机器
# ping测试
ping  192.168.111.100


# 如果失败后清理后，重新实验
#docker rm -f k8s-keepalived
#ip a del 192.168.111.100/32 dev ens33

配置kubelet(所有节点操作)

# 配置kubelet使用国内pause镜像
# 配置kubelet的cgroups

cat >/etc/sysconfig/kubelet<<EOF
KUBELET_EXTRA_ARGS="--cgroup-driver=cgroupfs  --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.1"
EOF

# 启动
systemctl daemon-reload
systemctl enable kubelet && systemctl restart kubelet

配置k8smaster01(192.168.111.128上操作)

cd /etc/kubernetes
# 生成配置文件
cat >kubeadm-master.config<<EOF
apiVersion: kubeadm.k8s.io/v1alpha2
kind: MasterConfiguration
kubernetesVersion: v1.11.1
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers

apiServerCertSANs:
- "k8smaster01"
- "k8smaster02"
- "k8smaster03"
- "192.168.111.128"
- "192.168.111.129"
- "192.168.111.130"
- "192.168.111.100"
- "127.0.0.1"

api:
  advertiseAddress: 192.168.111.128
  controlPlaneEndpoint: 192.168.111.100:8443

etcd:
  local:
    extraArgs:
      listen-client-urls: "https://127.0.0.1:2379,https://192.168.111.128:2379"
      advertise-client-urls: "https://192.168.111.128:2379"
      listen-peer-urls: "https://192.168.111.128:2380"
      initial-advertise-peer-urls: "https://192.168.111.128:2380"
      initial-cluster: "k8smaster01=https://192.168.111.128:2380"
    serverCertSANs:
      - k8smaster01
      - 192.168.111.128
    peerCertSANs:
      - k8smaster01
      - 192.168.111.128

controllerManagerExtraArgs:
  node-monitor-grace-period: 10s
  pod-eviction-timeout: 10s

networking:
  podSubnet: 10.244.0.0/16

kubeProxy:
  config:
    mode: ipvs
    # mode: iptables
EOF

# 提前拉取镜像
# 如果执行失败 可以多次执行
kubeadm config images pull --config kubeadm-master.config

# 初始化
# 注意保存返回的 join 命令
kubeadm init --config kubeadm-master.config

# 初始化失败时使用
#kubeadm reset

# 将ca相关文件传至其他master节点
cd /etc/kubernetes/pki/
USER=root 
CONTROL_PLANE_IPS="k8smaster02 k8smaster03"
for host in ${CONTROL_PLANE_IPS}; do
　　 ssh "${USER}"@$host "mkdir -p /etc/kubernetes/pki/etcd"
    scp ca.crt ca.key  sa.key  sa.pub front-proxy-ca.crt front-proxy-ca.key  "${USER}"@$host:/etc/kubernetes/pki/
    scp etcd/ca.crt etcd/ca.key "${USER}"@$host:/etc/kubernetes/pki/etcd/
　　scp ../admin.conf "${USER}"@$host:/etc/kubernetes/

done

kubeadm init失败解决：

将阿里云image tag成官方的image，即可解决init失败问题。(v1.11.0有此问题)

docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver-amd64:v1.11.1 k8s.gcr.io/kube-apiserver-amd64:v1.11.1
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy-amd64:v1.11.1 k8s.gcr.io/kube-proxy-amd64:v1.11.1
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/etcd-amd64:3.2.18 k8s.gcr.io/etcd-amd64:3.2.18
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler-amd64:v1.11.1 k8s.gcr.io/kube-scheduler-amd64:v1.11.1
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager-amd64:v1.11.1 k8s.gcr.io/kube-controller-manager-amd64:v1.11.1
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.1.3 k8s.gcr.io/coredns:1.1.3
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.1 k8s.gcr.io/pause-amd64:3.1
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1 k8s.gcr.io/pause:3.1

配置k8smaster02(192.168.111.129上操作)

cd /etc/kubernetes
# 生成配置文件
cat >kubeadm-master.config<<EOF
apiVersion: kubeadm.k8s.io/v1alpha2
kind: MasterConfiguration
kubernetesVersion: v1.11.1
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers

apiServerCertSANs:
- "k8smaster01"
- "k8smaster02"
- "k8smaster03"
- "192.168.111.128"
- "192.168.111.129"
- "192.168.111.130"
- "192.168.111.100"
- "127.0.0.1"

api:
  advertiseAddress: 192.168.111.129
  controlPlaneEndpoint: 192.168.111.100:8443

etcd:
  local:
    extraArgs:
      listen-client-urls: "https://127.0.0.1:2379,https://192.168.111.129:2379"
      advertise-client-urls: "https://192.168.111.129:2379"
      listen-peer-urls: "https://192.168.111.129:2380"
      initial-advertise-peer-urls: "https://192.168.111.129:2380"
      initial-cluster: "k8smaster01=https://192.168.111.128:2380,k8smaster02=https://192.168.111.129:2380"
      initial-cluster-state: existing
    serverCertSANs:
      - k8smaster02
      - 192.168.111.129
    peerCertSANs:
      - k8smaster02
      - 192.168.111.129

controllerManagerExtraArgs:
  node-monitor-grace-period: 10s
  pod-eviction-timeout: 10s

networking:
  podSubnet: 10.244.0.0/16

kubeProxy:
  config:
    mode: ipvs
    # mode: iptables
EOF

# 配置kubelet
kubeadm alpha phase certs all --config kubeadm-master.config
kubeadm alpha phase kubelet config write-to-disk --config kubeadm-master.config
kubeadm alpha phase kubelet write-env-file --config kubeadm-master.config
kubeadm alpha phase kubeconfig kubelet --config kubeadm-master.config
systemctl restart kubelet

# 添加etcd到集群中
export KUBECONFIG=/etc/kubernetes/admin.conf 
kubectl exec -n kube-system etcd-k8smaster01 -- etcdctl --ca-file /etc/kubernetes/pki/etcd/ca.crt --cert-file /etc/kubernetes/pki/etcd/peer.crt --key-file /etc/kubernetes/pki/etcd/peer.key --endpoints=https://192.168.111.128:2379 member add k8smaster02 https://192.168.111.129:2380

# 提前拉取镜像
kubeadm config images pull --config kubeadm-master.config

# 部署
kubeadm alpha phase kubeconfig all --config kubeadm-master.config
kubeadm alpha phase controlplane all --config kubeadm-master.config
kubeadm alpha phase mark-master --config kubeadm-master.config

配置k8smaster03(192.168.111.130上操作)

cd /etc/kubernetes
# 生成配置文件
cat >kubeadm-master.config<<EOF
apiVersion: kubeadm.k8s.io/v1alpha2
kind: MasterConfiguration
kubernetesVersion: v1.11.1
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers

apiServerCertSANs:
- "k8smaster01"
- "k8smaster02"
- "k8smaster03"
- "192.168.111.128"
- "192.168.111.129"
- "192.168.111.130"
- "192.168.111.100"
- "127.0.0.1"

api:
  advertiseAddress: 192.168.111.130
  controlPlaneEndpoint: 192.168.111.100:8443

etcd:
  local:
    extraArgs:
      listen-client-urls: "https://127.0.0.1:2379,https://192.168.111.130:2379"
      advertise-client-urls: "https://192.168.111.130:2379"
      listen-peer-urls: "https://192.168.111.130:2380"
      initial-advertise-peer-urls: "https://192.168.111.130:2380"
      initial-cluster: "k8smaster01=https://192.168.111.128:2380,k8smaster02=https://192.168.111.129:2380,k8smaster03=https://192.168.111.130:2380"
      initial-cluster-state: existing
    serverCertSANs:
      - k8smaster03
      - 192.168.111.130
    peerCertSANs:
      - k8smaster03
      - 192.168.111.130

controllerManagerExtraArgs:
  node-monitor-grace-period: 10s
  pod-eviction-timeout: 10s

networking:
  podSubnet: 10.244.0.0/16

kubeProxy:
  config:
    mode: ipvs
    # mode: iptables
EOF
# 配置kubelet
kubeadm alpha phase certs all --config kubeadm-master.config
kubeadm alpha phase kubelet config write-to-disk --config kubeadm-master.config
kubeadm alpha phase kubelet write-env-file --config kubeadm-master.config
kubeadm alpha phase kubeconfig kubelet --config kubeadm-master.config
systemctl restart kubelet

# 添加etcd到集群中
KUBECONFIG=/etc/kubernetes/admin.conf
kubectl exec -n kube-system etcd-k8smaster01 -- etcdctl --ca-file /etc/kubernetes/pki/etcd/ca.crt --cert-file /etc/kubernetes/pki/etcd/peer.crt --key-file /etc/kubernetes/pki/etcd/peer.key --endpoints=https://192.168.111.128:2379 member add k8smaster03 https://192.168.111.130:2380

# 提前拉取镜像
kubeadm config images pull --config kubeadm-master.config

# 部署
kubeadm alpha phase kubeconfig all --config kubeadm-master.config
kubeadm alpha phase controlplane all --config kubeadm-master.config
kubeadm alpha phase mark-master --config kubeadm-master.config

配置使用kubectl (master 任意节点执行)

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

# 查看node节点

　kubectl get nodes

 

# 只有网络插件也安装配置完成之后，才能会显示为ready状态

# 设置master允许部署应用pod，参与工作负载，现在可以部署其他系统组件

配置使用网络插件（任意master节点上操作）

# 下载配置
cd /etc/kubernetes
mkdir flannel && cd flannel
wget https://raw.githubusercontent.com/coreos/flannel/v0.10.0/Documentation/kube-flannel.yml
 
# 修改配置
# 此处的ip配置要与上面kubeadm的pod-network一致
  net-conf.json: |
    {
      "Network": "10.244.0.0/16",
      "Backend": {
        "Type": "vxlan"
      }
    }
 
# 修改镜像
image: registry.cn-shanghai.aliyuncs.com/gcr-k8s/flannel:v0.10.0-amd64
 
# 如果Node有多个网卡的话，参考flannel issues 39701，
# https://github.com/kubernetes/kubernetes/issues/39701
# 目前需要在kube-flannel.yml中使用--iface参数指定集群主机内网网卡的名称，
# 否则可能会出现dns无法解析。容器无法通信的情况，需要将kube-flannel.yml下载到本地，
# flanneld启动参数加上--iface=<iface-name>
    containers:
      - name: kube-flannel
        image: registry.cn-shanghai.aliyuncs.com/gcr-k8s/flannel:v0.10.0-amd64
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        - --iface=ens33
 
# 启动
kubectl apply -f kube-flannel.yml
 
# 查看
kubectl get pods --namespace kube-system
kubectl get svc --namespace kube-system

配置node节点加入集群（所有的node节点上操作）

以下上master生成的，与你环境可能不符合  
kubeadm join 192.168.111.100:8443 --token uf9oul.7k4csgxe5p7upvdb --discovery-token-ca-cert-hash sha256:36bc173b46eb0545fc30dd5db2d27dab70a257bd406fd791647d991a69454595

node节点报错处理办法：

tail -f /var/log/message

Jul 19 07:52:21 localhost kubelet: E0726 07:52:21.336281   10018 summary.go:102] Failed to get system container stats for "/system.slice/kubelet.service": failed to get cgroup stats for "/system.slice/kubelet.service": failed to get container info for "/system.slice/kubelet.service": unknown container "/system.slice/kubelet.service"

在kubelet配置文件追加以下配置

/etc/sysconfig/kubelet

# Append configuration in Kubelet
--runtime-cgroups=/systemd/system.slice --kubelet-cgroups=/systemd/system.slice
 

这样一个集群环境配置完成里，其余的是自己添加附件吧。