k8s安装之Master

Posted 2021-03-24

配置和启动kube-apiserver

创建kube-apiserver.service

/usr/lib/systemd/system/kube-apiserver.service
[Unit]
Description=Kubernetes API Service
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
After=etcd.service
[Service]
EnvironmentFile=-/etc/kubernetes/config
ExecStart=/usr/local/bin/kube-apiserver         --anonymous-auth=false         --basic-auth-file=/etc/kubernetes/basic_auth_file         $KUBE_LOGTOSTDERR         $KUBE_LOG_LEVEL         $KUBE_ALLOW_PRIV         --etcd-servers=https://172.16.20.206:2379,https://172.16.20.207:2379,https://172.16.20.208:2379         --advertise-address=172.16.20.206         --bind-address=0.0.0.0         --insecure-bind-address=0.0.0.0         --service-cluster-ip-range=10.254.0.0/16         --admission-control=ServiceAccount,NamespaceLifecycle,NamespaceExists,LimitRanger,ResourceQuota         --authorization-mode=RBAC,Node         --runtime-config=rbac.authorization.k8s.io/v1beta1         --kubelet-https=true --enable-bootstrap-token-auth=true         --token-auth-file=/etc/kubernetes/token.csv         --service-node-port-range=30000-32767         --tls-cert-file=/etc/kubernetes/ssl/kubernetes.pem         --tls-private-key-file=/etc/kubernetes/ssl/kubernetes-key.pem         --client-ca-file=/etc/kubernetes/ssl/ca.pem         --service-account-key-file=/etc/kubernetes/ssl/ca-key.pem         --etcd-cafile=/etc/kubernetes/ssl/ca.pem         --etcd-certfile=/etc/kubernetes/ssl/kubernetes.pem         --etcd-keyfile=/etc/kubernetes/ssl/kubernetes-key.pem         --enable-swagger-ui=true         --apiserver-count=3         --allow-privileged=true         --audit-log-maxage=30         --audit-log-maxbackup=3         --audit-log-maxsize=100         --audit-log-path=/var/lib/audit.log         --event-ttl=1h
Restart=on-failure
Type=notify
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target

说明

--authorization-mode=RBAC 指定在安全端口使用 RBAC 授权模式，拒绝未通过授权的请求；
kube-scheduler、kube-controller-manager 一般和 kube-apiserver 部署在同一台机器上，它们使用非安全端口和 kube-apiserver通信;
kubelet、kube-proxy、kubectl 部署在其它 Node 节点上，如果通过安全端口访问 kube-apiserver，则必须先通过 TLS 证书认证，再通过 RBAC 授权；
kube-proxy、kubectl 通过在使用的证书里指定相关的 User、Group 来达到通过 RBAC 授权的目的；
如果使用了 kubelet TLS Boostrap 机制，则不能再指定 --kubelet-certificate-authority、--kubelet-client-certificate 和 --kubelet-client-key 选项，否则后续 kube-apiserver 校验 kubelet 证书时出现 ”x509: certificate signed by unknown authority“ 错误；
--admission-control 值必须包含 ServiceAccount；
--bind-address 不能为 127.0.0.1；
runtime-config配置表示运行时的apiVersion :rbac.authorization.k8s.io/v1beta1
--service-cluster-ip-range 指定 Service Cluster IP 地址段，该地址段不能路由可达；
缺省情况下 kubernetes 对象保存在 etcd /registry 路径下，可以通过 --etcd-prefix 参数进行调整；

启动kube-apiserver

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

配置kube-controller-manager

创建kube-controller-manager.service

/usr/lib/systemd/system/kube-controller-manager.service
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
EnvironmentFile=-/etc/kubernetes/config
ExecStart=/usr/local/bin/kube-controller-manager         $KUBE_LOGTOSTDERR         $KUBE_LOG_LEVEL         $KUBE_MASTER         --address=127.0.0.1         --service-cluster-ip-range=10.254.0.0/16         --cluster-name=kubernetes         --cluster-signing-cert-file=/etc/kubernetes/ssl/ca.pem         --cluster-signing-key-file=/etc/kubernetes/ssl/ca-key.pem          --service-account-private-key-file=/etc/kubernetes/ssl/ca-key.pem         --root-ca-file=/etc/kubernetes/ssl/ca.pem         --leader-elect=true
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target

说明

-–master=http://{MASTER_IP}:8080：使用非安全 8080 端口与 kube-apiserver 通信；
–-cluster-cidr 指定 Cluster 中 Pod 的 CIDR 范围，该网段在各 Node 间必须路由可达(flanneld保证)；
--service-cluster-ip-range 参数指定 Cluster 中 Service 的CIDR范围，该网络在各 Node 间必须路由不可达，必须和 kube-apiserver 中的参数一致；
--cluster-signing-* 指定的证书和私钥文件用来签名为 TLS BootStrap 创建的证书和私钥；
--root-ca-file 用来对 kube-apiserver 证书进行校验，指定该参数后，才会在Pod 容器的 ServiceAccount 中放置该 CA 证书文件；
--address 值必须为 127.0.0.1，因为当前 kube-apiserver 期望 scheduler 和 controller-manager 在同一台机器
-–leader-elect=true 部署多台机器组成的 master 集群时选举产生一处于工作状态的 kube-controller-manager 进程

启动

systemctl daemon-reload
systemctl enable kube-controller-manager
systemctl start kube-controller-manager

验证

kubectl get componentstatuses
NAME                 STATUS      MESSAGE                                                                                     ERROR
scheduler            Unhealthy   Get http://127.0.0.1:10251/healthz: dial tcp 127.0.0.1:10251: connect: connection refused   
controller-manager   Healthy     ok                                                                                          
etcd-1               Healthy     {"health":"true"}                                                                           
etcd-2               Healthy     {"health":"true"}                                                                           
etcd-0               Healthy     {"health":"true"}

配置kube-scheduler

创建kube-scheduler.service

/usr/lib/systemd/system/kube-scheduler.service
[Unit]
Description=Kubernetes Scheduler Plugin
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
EnvironmentFile=-/etc/kubernetes/config
ExecStart=/usr/local/bin/kube-scheduler             $KUBE_LOGTOSTDERR             $KUBE_LOG_LEVEL             $KUBE_MASTER             --leader-elect=true             --address=127.0.0.1
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target

启动

systemctl daemon-reload
systemctl start kube-scheduler

验证

kubectl get componentstatuses
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-0               Healthy   {"health":"true"}   
etcd-1               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"}

kubectl get cs    (上面命令的简写)
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-0               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"}   
etcd-1               Healthy   {"health":"true"}