部署master節點 · kubernetes完整攻略

# 部署master節點 kubernetes master 節點包含的組件： + kube-apiserver + kube-scheduler + kube-controller-manager 目前這三個組件需要部署在同一臺機器上。 + `kube-scheduler`、`kube-controller-manager` 和 `kube-apiserver` 三者的功能緊密相關； + 同時只能有一個 `kube-scheduler`、`kube-controller-manager` 進程處于工作狀態，如果運行多個，則需要通過選舉產生一個 leader； **注**： - 暫時未實現master節點的高可用 - master節點上沒有部署flannel網絡插件，如果想要在master節點上也能訪問ClusterIP，請參考下一節[部署node節點](node-installation.md)中的配置Flanneld部分。 ## TLS 證書文件以下`pem`證書文件我們在[創建TLS證書和秘鑰](create-tls-and-secret-key.md)這一步中已經創建過了，`token.csv`文件在[創建kubeconfig文件](create-kubeconfig.md)的時候創建。我們再檢查一下。 ``` bash $ ls /etc/kubernetes/ssl admin-key.pem admin.pem ca-key.pem ca.pem kube-proxy-key.pem kube-proxy.pem kubernetes-key.pem kubernetes.pem ``` ## 下載最新版本的二進制文件有兩種下載方式，請注意下載對應的Kubernetes版本。 **方式一** 從 [github release 頁面](https://github.com/kubernetes/kubernetes/releases) 下載發布版 tarball，解壓后再執行下載腳本 ``` bash wget https://github.com/kubernetes/kubernetes/releases/download/v1.6.0/kubernetes.tar.gz tar -xzvf kubernetes.tar.gz cd kubernetes ./cluster/get-kube-binaries.sh ``` **方式二** 從 [`CHANGELOG`頁面](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG.md) 下載 `client` 或 `server` tarball 文件 `server` 的 tarball `kubernetes-server-linux-amd64.tar.gz` 已經包含了 `client`(`kubectl`) 二進制文件，所以不用單獨下載`kubernetes-client-linux-amd64.tar.gz`文件； ```bash # wget https://dl.k8s.io/v1.6.0/kubernetes-client-linux-amd64.tar.gz wget https://dl.k8s.io/v1.6.0/kubernetes-server-linux-amd64.tar.gz tar -xzvf kubernetes-server-linux-amd64.tar.gz cd kubernetes tar -xzvf kubernetes-src.tar.gz ``` 將二進制文件拷貝到指定路徑 ``` bash cp -r server/bin/{kube-apiserver,kube-controller-manager,kube-scheduler,kubectl,kube-proxy,kubelet} /usr/local/bin/ ``` ## 配置和啟動 kube-apiserver **創建 kube-apiserver的service配置文件** service配置文件`/usr/lib/systemd/system/kube-apiserver.service`內容： ```ini [Unit] Description=Kubernetes API Service Documentation=https://github.com/GoogleCloudPlatform/kubernetes After=network.target After=etcd.service [Service] EnvironmentFile=-/etc/kubernetes/config EnvironmentFile=-/etc/kubernetes/apiserver ExecStart=/usr/local/bin/kube-apiserver \ $KUBE_LOGTOSTDERR \ $KUBE_LOG_LEVEL \ $KUBE_ETCD_SERVERS \ $KUBE_API_ADDRESS \ $KUBE_API_PORT \ $KUBELET_PORT \ $KUBE_ALLOW_PRIV \ $KUBE_SERVICE_ADDRESSES \ $KUBE_ADMISSION_CONTROL \ $KUBE_API_ARGS Restart=on-failure Type=notify LimitNOFILE=65536 [Install] WantedBy=multi-user.target ``` `/etc/kubernetes/config`文件的內容為： ```ini ### # kubernetes system config # # The following values are used to configure various aspects of all # kubernetes services, including # # kube-apiserver.service # kube-controller-manager.service # kube-scheduler.service # kubelet.service # kube-proxy.service # logging to stderr means we get it in the systemd journal KUBE_LOGTOSTDERR="--logtostderr=true" # journal message level, 0 is debug KUBE_LOG_LEVEL="--v=0" # Should this cluster be allowed to run privileged docker containers KUBE_ALLOW_PRIV="--allow-privileged=true" # How the controller-manager, scheduler, and proxy find the apiserver #KUBE_MASTER="--master=http://test-001.jimmysong.io:8080" KUBE_MASTER="--master=http://172.20.0.113:8080" ``` 該配置文件同時被kube-apiserver、kube-controller-manager、kube-scheduler、kubelet、kube-proxy使用。 apiserver配置文件`/etc/kubernetes/apiserver`內容為： ``` Ini ### ## kubernetes system config ## ## The following values are used to configure the kube-apiserver ## # ## The address on the local server to listen to. #KUBE_API_ADDRESS="--insecure-bind-address=test-001.jimmysong.io" KUBE_API_ADDRESS="--advertise-address=172.20.0.113 --bind-address=172.20.0.113 --insecure-bind-address=172.20.0.113" # ## The port on the local server to listen on. #KUBE_API_PORT="--port=8080" # ## Port minions listen on #KUBELET_PORT="--kubelet-port=10250" # ## Comma separated list of nodes in the etcd cluster KUBE_ETCD_SERVERS="--etcd-servers=https://172.20.0.113:2379,https://172.20.0.114:2379,https://172.20.0.115:2379" # ## Address range to use for services KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16" # ## default admission control policies KUBE_ADMISSION_CONTROL="--admission-control=ServiceAccount,NamespaceLifecycle,NamespaceExists,LimitRanger,ResourceQuota" # ## Add your own! KUBE_API_ARGS="--authorization-mode=RBAC --runtime-config=rbac.authorization.k8s.io/v1beta1 --kubelet-https=true --experimental-bootstrap-token-auth --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 --audit-log-maxage=30 --audit-log-maxbackup=3 --audit-log-maxsize=100 --audit-log-path=/var/lib/audit.log --event-ttl=1h" ``` + `--experimental-bootstrap-token-auth` Bootstrap Token Authentication在1.9版本已經變成了正式feature，參數名稱改為`--enable-bootstrap-token-auth` + 如果中途修改過`--service-cluster-ip-range`地址，則必須將default命名空間的`kubernetes`的service給刪除，使用命令：`kubectl delete service kubernetes`，然后系統會自動用新的ip重建這個service，不然apiserver的log有報錯`the cluster IP x.x.x.x for service kubernetes/default is not within the service CIDR x.x.x.x/16; please recreate` + `--authorization-mode=RBAC` 指定在安全端口使用 RBAC 授權模式，拒絕未通過授權的請求； + kube-scheduler、kube-controller-manager 一般和 kube-apiserver 部署在同一臺機器上，它們使用**非安全端口**和 kube-apiserver通信; + kubelet、kube-proxy、kubectl 部署在其它 Node 節點上，如果通過**安全端口**訪問 kube-apiserver，則必須先通過 TLS 證書認證，再通過 RBAC 授權； + kube-proxy、kubectl 通過在使用的證書里指定相關的 User、Group 來達到通過 RBAC 授權的目的； + 如果使用了 kubelet TLS Boostrap 機制，則不能再指定 `--kubelet-certificate-authority`、`--kubelet-client-certificate` 和 `--kubelet-client-key` 選項，否則后續 kube-apiserver 校驗 kubelet 證書時出現 ”x509: certificate signed by unknown authority“ 錯誤； + `--admission-control` 值必須包含 `ServiceAccount`； + `--bind-address` 不能為 `127.0.0.1`； + `runtime-config`配置為`rbac.authorization.k8s.io/v1beta1`，表示運行時的apiVersion； + `--service-cluster-ip-range` 指定 Service Cluster IP 地址段，該地址段不能路由可達； + 缺省情況下 kubernetes 對象保存在 etcd `/registry` 路徑下，可以通過 `--etcd-prefix` 參數進行調整； + 如果需要開通http的無認證的接口，則可以增加以下兩個參數：`--insecure-port=8080 --insecure-bind-address=127.0.0.1`。注意，生產上不要綁定到非127.0.0.1的地址上 **Kubernetes 1.9** - 對于Kubernetes1.9集群，需要注意配置`KUBE_API_ARGS`環境變量中的`--authorization-mode=Node,RBAC`，增加對`Node`授權的模式，否則將無法注冊node。 - `--experimental-bootstrap-token-auth` Bootstrap Token Authentication在kubernetes 1.9版本已經廢棄，參數名稱改為`--enable-bootstrap-token-auth` 完整 unit 見 [kube-apiserver.service](../systemd/kube-apiserver.service) **啟動kube-apiserver** ``` bash systemctl daemon-reload systemctl enable kube-apiserver systemctl start kube-apiserver systemctl status kube-apiserver ``` ## 配置和啟動 kube-controller-manager **創建 kube-controller-manager的serivce配置文件** 文件路徑`/usr/lib/systemd/system/kube-controller-manager.service` ```ini [Unit] Description=Kubernetes Controller Manager Documentation=https://github.com/GoogleCloudPlatform/kubernetes [Service] EnvironmentFile=-/etc/kubernetes/config EnvironmentFile=-/etc/kubernetes/controller-manager ExecStart=/usr/local/bin/kube-controller-manager \ $KUBE_LOGTOSTDERR \ $KUBE_LOG_LEVEL \ $KUBE_MASTER \ $KUBE_CONTROLLER_MANAGER_ARGS Restart=on-failure LimitNOFILE=65536 [Install] WantedBy=multi-user.target ``` 配置文件`/etc/kubernetes/controller-manager`。 ``` ini ### # The following values are used to configure the kubernetes controller-manager # defaults from config and apiserver should be adequate # Add your own! KUBE_CONTROLLER_MANAGER_ARGS="--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" ``` + `--service-cluster-ip-range` 參數指定 Cluster 中 Service 的CIDR范圍，該網絡在各 Node 間必須路由不可達，必須和 kube-apiserver 中的參數一致； + `--cluster-signing-*` 指定的證書和私鑰文件用來簽名為 TLS BootStrap 創建的證書和私鑰； + `--root-ca-file` 用來對 kube-apiserver 證書進行校驗，**指定該參數后，才會在Pod 容器的 ServiceAccount 中放置該 CA 證書文件**； + `--address` 值必須為 `127.0.0.1`，kube-apiserver 期望 scheduler 和 controller-manager 在同一臺機器； ### 啟動 kube-controller-manager ``` bash systemctl daemon-reload systemctl enable kube-controller-manager systemctl start kube-controller-manager systemctl status kube-controller-manager ``` 我們啟動每個組件后可以通過執行命令`kubectl get componentstatuses`，來查看各個組件的狀態; ```bash $ kubectl get componentstatuses NAME STATUS MESSAGE ERROR scheduler Unhealthy Get http://127.0.0.1:10251/healthz: dial tcp 127.0.0.1:10251: getsockopt: connection refused controller-manager Healthy ok etcd-2 Healthy {"health": "true"} etcd-0 Healthy {"health": "true"} etcd-1 Healthy {"health": "true"} ``` - 如果有組件report unhealthy請參考：https://github.com/kubernetes-incubator/bootkube/issues/64 完整 unit 見 [kube-controller-manager.service](../systemd/kube-controller-manager.service) ## 配置和啟動 kube-scheduler **創建 kube-scheduler的serivce配置文件** 文件路徑`/usr/lib/systemd/system/kube-scheduler.service`。 ```ini [Unit] Description=Kubernetes Scheduler Plugin Documentation=https://github.com/GoogleCloudPlatform/kubernetes [Service] EnvironmentFile=-/etc/kubernetes/config EnvironmentFile=-/etc/kubernetes/scheduler ExecStart=/usr/local/bin/kube-scheduler \ $KUBE_LOGTOSTDERR \ $KUBE_LOG_LEVEL \ $KUBE_MASTER \ $KUBE_SCHEDULER_ARGS Restart=on-failure LimitNOFILE=65536 [Install] WantedBy=multi-user.target ``` 配置文件`/etc/kubernetes/scheduler`。 ``` Ini ### # kubernetes scheduler config # default config should be adequate # Add your own! KUBE_SCHEDULER_ARGS="--leader-elect=true --address=127.0.0.1" ``` + `--address` 值必須為 `127.0.0.1`，因為當前 kube-apiserver 期望 scheduler 和 controller-manager 在同一臺機器；完整 unit 見 [kube-scheduler.service](../systemd/kube-scheduler.service) ### 啟動 kube-scheduler ``` bash systemctl daemon-reload systemctl enable kube-scheduler systemctl start kube-scheduler systemctl status kube-scheduler ``` ## 驗證 master 節點功能 ``` bash $ 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"} ```