kubeadm 搭建K8S 1.18集群--安装kubeadm和api-server

#这里我在k8s-01 k8s-02 k8s-03执行master节点操作
yum install -y \
    kubeadm-1.18.3 \
    kubectl-1.18.3 \
    kubelet-1.18.3 \
    --disableexcludes=kubernetes && \
    systemctl enable kubelet
#kubeadm 安装集群
#kubectl 通过命令行访问apiserver
#kubelet 负责Pod对应容器的创建、停止等任务
#node节点不需要安装kubectl，kubectl是一个agent读取kubeconfig访问api-server来操作集群，node节点一般不需要

#node节点安装默认是在所有节点安装，但是k8s中的master节点已经安装过了，我们就只在k8s-04 k8s-05中安装
yum install -y \
    kubeadm-1.18.3 \
    kubelet-1.18.3 \
    --disableexcludes=kubernetes && \
    systemctl enable kubelet

#首先我们在原有的基础上添加一个host，只需要在master节点上执行即可
cat >>/etc/hosts<< EOF
192.168.31.100  k8s-master-01
192.168.31.101  k8s-master-02
192.168.31.102  k8s-master-03
192.168.31.105  k8s-master
EOF

mkdir -p /etc/kubernetes
cat > /etc/kubernetes/nginx.conf << EOF
user nginx nginx;
worker_processes auto;
events {
    worker_connections  20240;
    use epoll;
}
error_log /var/log/nginx_error.log info;
stream {
    upstream kube-servers {
        hash $remote_addr consistent;
        server k8s-master-01:6443 weight=5 max_fails=1 fail_timeout=3s;  #这里可以写IP
        server k8s-master-02:6443 weight=5 max_fails=1 fail_timeout=3s;
        server k8s-master-03:6443 weight=5 max_fails=1 fail_timeout=3s;
    }
    server {
        listen 8443 reuseport;
        proxy_connect_timeout 3s;
        # 加大timeout
        proxy_timeout 3000s;
        proxy_pass kube-servers;
    }
}
EOF

#这里我使用容器运行nginx，当然自己也可以写成staticPod的yaml在init的阶段放入目录里，或者二进制安装nginx
docker run --restart=always \
    -v /etc/kubernetes/nginx.conf:/etc/nginx/nginx.conf \
    -v /etc/localtime:/etc/localtime:ro \
    --name k8s \
    --net host \
    -d \
    nginx:alpine

[root@k8s-01 ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
d8b3955bda68        nginx:alpine        "nginx -g 'daemon of…"   2 minutes ago       Up 2 minutes                            k8s
[root@k8s-01 ~]# lsof -i:8443
lsof: no pwd entry for UID 101
COMMAND  PID     USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
nginx   3360     root    5u  IPv4  58860      0t0  TCP *:pcsync-https (LISTEN)
lsof: no pwd entry for UID 101
nginx   3374      101    5u  IPv4  58860      0t0  TCP *:pcsync-https (LISTEN)