k8s学习笔记-部署master节点

主机列表

本次实验选择5台主机，3台作为master主机，2台作为node节点

节点ip	OS版本	hostname -f	安装软件
192.168.0.1	RHEL7.4	k8s-master01	docker,etcd,flanneld,kube-apiserver,kube-controller-manager,kube-scheduler
192.168.0.2	RHEL7.4	k8s-master02	docker,etcd,flanneld,kube-apiserver,kube-controller-manager,kube-scheduler
192.168.0.3	RHEL7.4	k8s-master03	docker,etcd,flanneld,kube-apiserver,kube-controller-manager,kube-scheduler
192.168.0.4	RHEL7.4	k8s-node01	docker,flanneld,kubelet,kube-proxy
192.168.0.5	RHEL7.4	k8s-node02	docker,flanneld,kubelet,kube-proxy

kubernetes master 节点包含的组件：

• kube-apiserver
• kube-scheduler
• kube-controller-manager

目前这三个组件需要部署在同一台机器上。

• kube-scheduler、kube-controller-manager 和 kube-apiserver三者的功能紧密相关；
• 同时只能有一个 kube-scheduler、kube-controller-manager 进程处于工作状态，如果运行多个，则需要通过选举产生一个 leader；

下载解压二进制文件

# wget https://dl.k8s.io/v1.15.3/kubernetes-server-linux-amd64.tar.gz 
# tar xf kubernetes-server-linux-amd64.tar.gz

# cd kubernetes/server/bin/
# cp  kubeadm  kube-apiserver  kube-controller-manager  kubectl  kube-scheduler  /k8s/kubernetes/bin/

配置和启动kube-apiserver  

创建kubernetes 证书

创建kubernetes 证书签名请求：

cat > kubernetes-csr.json < {
  "CN": "kubernetes",
  "hosts": [
    "127.0.0.1",
    "192.168.0.1",
    "192.168.0.2",
    "192.168.0.3",
    "101.254.0.1",
    "kubernetes",
    "kubernetes.default",
    "kubernetes.default.svc",
    "kubernetes.default.svc.cluster",
    "kubernetes.default.svc.cluster.local"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}
EOF    

• 如果 hosts 字段不为空，则需要指定授权使用该证书的 IP 或域名列表，所以上面分别指定了当前部署的 master 节点主机 IP，如有apiserver 负载地址或域名，也需一并指定
• 添加 kube-apiserver 注册的名为 kubernetes 的服务 IP (Service Cluster IP)，一般是 kube-apiserver --service-cluster-ip-range 选项值指定的网段的第一个IP，如 “101.254.0.1”

生成kubernetes 证书和私钥

# cfssl gencert -ca=/k8s/kubernetes/ssl/ca.pem   -ca-key=/k8s/kubernetes/ssl/ca-key.pem   -config=/k8s/kubernetes/ssl/ca-config.json   -profile=kubernetes kubernetes-csr.json | cfssljson -bare kubernetes

# ls kub*
kubernetes.csr  kubernetes-csr.json  kubernetes-key.pem  kubernetes.pem

# cp kubernetes*.pem /k8s/kubernetes/ssl/

创建kube-apiserver 使用的客户端token 文件

kubelet 首次启动时向kube-apiserver 发送TLS Bootstrapping 请求，kube-apiserver 验证请求中的token 是否与它配置的token.csv 一致，如果一致则自动为kubelet 生成证书和密钥。

TLS Bootstrapping 使用的Token可以使用命令生成

# head -c 16 /dev/urandom | od -An -t x | tr -d ' '
ef502f26a00ac235b04977cde1dc9916

cat << EOF > /k8s/kubernetes/cfg/token.csv
ef502f26a00ac235b04977cde1dc9916,kubelet-bootstrap,10001,"system:kubelet-bootstrap"    
EOF

创建apiserver配置文件

cat << EOF > /k8s/kubernetes/cfg/kube-apiserver 
KUBE_APISERVER_OPTS="--logtostderr=true \
--v=4 \
--etcd-servers=https://192.168.0.3:2379,https://192.168.0.2:2379,https://192.168.0.1:2379 \
--bind-address=192.168.0.1 \
--secure-port=6443 \
--advertise-address=192.168.0.1 \
--allow-privileged=true \
--service-cluster-ip-range=101.254.0.0/16 \
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota,NodeRestriction \
--authorization-mode=RBAC,Node \
--enable-bootstrap-token-auth \
--token-auth-file=/k8s/kubernetes/cfg/token.csv \
--service-node-port-range=30000-50000 \
--tls-cert-file=/k8s/kubernetes/ssl/kubernetes.pem  \
--tls-private-key-file=/k8s/kubernetes/ssl/kubernetes-key.pem \
--client-ca-file=/k8s/kubernetes/ssl/ca.pem \
--service-account-key-file=/k8s/kubernetes/ssl/ca-key.pem \
--etcd-cafile=/k8s/kubernetes/ssl/ca.pem \
--etcd-certfile=/k8s/kubernetes/ssl/kubernetes.pem \
--etcd-keyfile=/k8s/kubernetes/ssl/kubernetes-key.pem"
EOF    

提示：其他master节点需要将红字部分替换 

创建kube-apiserver 的systemd unit文件

cat << EOF > /lib/systemd/system/kube-apiserver.service
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=-/k8s/kubernetes/cfg/kube-apiserver
ExecStart=/k8s/kubernetes/bin/kube-apiserver \$KUBE_APISERVER_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target    
EOF

启动kube-apiserver服务

systemctl daemon-reload
systemctl enable kube-apiserver
systemctl start kube-apiserver
systemctl status kube-apiserver

授予kubernetes证书访问kubelet api权限

kubectl create clusterrolebinding kube-apiserver:kubelet-apis --clusterrole=system:kubelet-api-admin --user kubernetes

配置和启动kube-controller-manager

创建kube-controller-manager配置文件

cat << EOF > /k8s/kubernetes/cfg/kube-controller-manager
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=true \
--v=4 \
--master=127.0.0.1:8080 \
--leader-elect=true \
--address=127.0.0.1 \
--service-cluster-ip-range=101.254.0.0/24 \
--cluster-cidr=100.100.0.0/16 \
--cluster-name=kubernetes \
--cluster-signing-cert-file=/k8s/kubernetes/ssl/ca.pem \
--cluster-signing-key-file=/k8s/kubernetes/ssl/ca-key.pem  \
--root-ca-file=/k8s/kubernetes/ssl/ca.pem \
--service-account-private-key-file=/k8s/kubernetes/ssl/ca-key.pem"    
EOF

 提示：

• 之前的kube-apiserver默认开启监听非安全端口8080，开启了127.0.0.1的本地非安全认证，所以同一节点的kube-controller-manager可以直接配置本地认证，无需单独为其创建证书
• 如kube-apiserver配置--insecure-port=0，关闭监听非安全端口(8080)，则需要单独为kube-controller-manager创建证书。

创建kube-controller-manager systemd unit 文件

cat << EOF > /lib/systemd/system/kube-controller-manager.service 
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=-/k8s/kubernetes/cfg/kube-controller-manager
ExecStart=/k8s/kubernetes/bin/kube-controller-manager \$KUBE_CONTROLLER_MANAGER_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target    
EOF

启动 kube-controller-manager服务

systemctl daemon-reload
systemctl enable kube-controller-manager
systemctl restart kube-controller-manager
systemctl status kube-controller-manager

配置和启动kube-scheduler

创建kube-scheduler配置文件

cat << EOF > /k8s/kubernetes/cfg/kube-scheduler
KUBE_SCHEDULER_OPTS="--logtostderr=true --v=4 --master=127.0.0.1:8080 --leader-elect=true"
EOF

创建kube-scheduler systemd unit 文件

cat << EOF > /lib/systemd/system/kube-scheduler.service
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=-/k8s/kubernetes/cfg/kube-scheduler
ExecStart=/k8s/kubernetes/bin/kube-scheduler \$KUBE_SCHEDULER_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target    
EOF

启动kube-scheduler服务

systemctl daemon-reload
systemctl enable kube-scheduler.service 
systemctl restart kube-scheduler.service
systemctl status kube-scheduler.service

验证master 节点

将可执行文件添加到 PATH 变量中

echo "export PATH=$PATH:/k8s/kubernetes/bin/" >>/etc/profile
source /etc/profile

#查看master服务状态
# kubectl get cs 
NAME                 STATUS    MESSAGE             ERROR
controller-manager   Healthy   ok                  
scheduler            Healthy   ok                  
etcd-1               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"}   
etcd-0               Healthy   {"health":"true"}     

分发文件至其他节点

scp -r /k8s/kubernetes/bin/* 192.168.0.2:/k8s/kubernetes/bin/
scp -r /k8s/kubernetes/bin/* 192.168.0.3:/k8s/kubernetes/bin/
scp -r /k8s/kubernetes/ssl/* 192.168.0.2:/k8s/kubernetes/ssl/
scp -r /k8s/kubernetes/ssl/* 192.168.0.3:/k8s/kubernetes/ssl/
scp -r /k8s/kubernetes/cfg/* 192.168.0.2:/k8s/kubernetes/cfg/
scp -r /k8s/kubernetes/cfg/* 192.168.0.3:/k8s/kubernetes/cfg/
scp /lib/systemd/system/kube-* 192.168.0.2:/lib/systemd/system/
scp /lib/systemd/system/kube-* 192.168.0.3:/lib/systemd/system/