部署master节点

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-schedulerkube-controller-managerkube-apiserver 三者的功能紧密相关;
  • 同时只能有一个 kube-schedulerkube-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;

  • 暂时未实现master节点的高可用
  • master节点上没有部署flannel网络插件,如果想要在master节点上也能访问ClusterIP,请参考下一节部署node节点中的配置Flanneld部分。

TLS 证书文件

以下pem证书文件我们在创建TLS证书和秘钥这一步中已经创建过了,token.csv文件在创建kubeconfig文件的时候创建。我们再检查一下。

  1. $ ls /etc/kubernetes/ssl
  2. admin-key.pem admin.pem ca-key.pem ca.pem kube-proxy-key.pem kube-proxy.pem kubernetes-key.pem kubernetes.pem

下载最新版本的二进制文件

有两种下载方式,请注意下载对应的Kubernetes版本。

方式一

github release 页面 下载发布版 tarball,解压后再执行下载脚本

  1. wget https://github.com/kubernetes/kubernetes/releases/download/v1.6.0/kubernetes.tar.gz
  2. tar -xzvf kubernetes.tar.gz
  3. cd kubernetes
  4. ./cluster/get-kube-binaries.sh

方式二

CHANGELOG页面 下载 clientserver tarball 文件

server 的 tarball kubernetes-server-linux-amd64.tar.gz 已经包含了 client(kubectl) 二进制文件,所以不用单独下载kubernetes-client-linux-amd64.tar.gz文件;

  1. # wget https://dl.k8s.io/v1.6.0/kubernetes-client-linux-amd64.tar.gz
  2. wget https://dl.k8s.io/v1.6.0/kubernetes-server-linux-amd64.tar.gz
  3. tar -xzvf kubernetes-server-linux-amd64.tar.gz
  4. cd kubernetes
  5. tar -xzvf kubernetes-src.tar.gz

将二进制文件拷贝到指定路径

  1. cp -r server/bin/{kube-apiserver,kube-controller-manager,kube-scheduler,kubectl,kube-proxy,kubelet} /usr/local/bin/

配置和启动 kube-apiserver

创建 kube-apiserver的service配置文件

service配置文件/usr/lib/systemd/system/kube-apiserver.service内容:

  1. [Unit]
  2. Description=Kubernetes API Service
  3. Documentation=https://github.com/GoogleCloudPlatform/kubernetes
  4. After=network.target
  5. After=etcd.service
  6. [Service]
  7. EnvironmentFile=-/etc/kubernetes/config
  8. EnvironmentFile=-/etc/kubernetes/apiserver
  9. ExecStart=/usr/local/bin/kube-apiserver \
  10. $KUBE_LOGTOSTDERR \
  11. $KUBE_LOG_LEVEL \
  12. $KUBE_ETCD_SERVERS \
  13. $KUBE_API_ADDRESS \
  14. $KUBE_API_PORT \
  15. $KUBELET_PORT \
  16. $KUBE_ALLOW_PRIV \
  17. $KUBE_SERVICE_ADDRESSES \
  18. $KUBE_ADMISSION_CONTROL \
  19. $KUBE_API_ARGS
  20. Restart=on-failure
  21. Type=notify
  22. LimitNOFILE=65536
  23. [Install]
  24. WantedBy=multi-user.target

/etc/kubernetes/config文件的内容为:

  1. ###
  2. # kubernetes system config
  3. #
  4. # The following values are used to configure various aspects of all
  5. # kubernetes services, including
  6. #
  7. # kube-apiserver.service
  8. # kube-controller-manager.service
  9. # kube-scheduler.service
  10. # kubelet.service
  11. # kube-proxy.service
  12. # logging to stderr means we get it in the systemd journal
  13. KUBE_LOGTOSTDERR="--logtostderr=true"
  14. # journal message level, 0 is debug
  15. KUBE_LOG_LEVEL="--v=0"
  16. # Should this cluster be allowed to run privileged docker containers
  17. KUBE_ALLOW_PRIV="--allow-privileged=true"
  18. # How the controller-manager, scheduler, and proxy find the apiserver
  19. #KUBE_MASTER="--master=http://sz-pg-oam-docker-test-001.tendcloud.com:8080"
  20. KUBE_MASTER="--master=http://172.20.0.113:8080"

该配置文件同时被kube-apiserver、kube-controller-manager、kube-scheduler、kubelet、kube-proxy使用。

apiserver配置文件/etc/kubernetes/apiserver内容为:

  1. ###
  2. ## kubernetes system config
  3. ##
  4. ## The following values are used to configure the kube-apiserver
  5. ##
  6. #
  7. ## The address on the local server to listen to.
  8. #KUBE_API_ADDRESS="--insecure-bind-address=sz-pg-oam-docker-test-001.tendcloud.com"
  9. KUBE_API_ADDRESS="--advertise-address=172.20.0.113 --bind-address=172.20.0.113 --insecure-bind-address=172.20.0.113"
  10. #
  11. ## The port on the local server to listen on.
  12. #KUBE_API_PORT="--port=8080"
  13. #
  14. ## Port minions listen on
  15. #KUBELET_PORT="--kubelet-port=10250"
  16. #
  17. ## Comma separated list of nodes in the etcd cluster
  18. KUBE_ETCD_SERVERS="--etcd-servers=https://172.20.0.113:2379,https://172.20.0.114:2379,https://172.20.0.115:2379"
  19. #
  20. ## Address range to use for services
  21. KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"
  22. #
  23. ## default admission control policies
  24. KUBE_ADMISSION_CONTROL="--admission-control=ServiceAccount,NamespaceLifecycle,NamespaceExists,LimitRanger,ResourceQuota"
  25. #
  26. ## Add your own!
  27. 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版本已经变成了正式feature,参数名称改为--enable-bootstrap-token-auth
  • 如果中途修改过--service-cluster-ip-range地址,则必须将default命名空间的kubernetes的service给删除,使用命令:kubectl delete service kubernetes,然后系统会自动用新的ip重建这个service,不然apiserver的log有报错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--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配置为rbac.authorization.k8s.io/v1beta1,表示运行时的apiVersion;
  • --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;
  • 如果需要开通http的无认证的接口,则可以增加以下两个参数:--insecure-port=8080 --insecure-bind-address=127.0.0.1。注意,生产上不要绑定到非127.0.0.1的地址上

Kubernetes 1.9

对于Kubernetes1.9集群,需要注意配置KUBE_API_ARGS环境变量中的--authorization-mode=Node,RBAC,增加对Node授权的模式,否则将无法注册node。

完整 unit 见 kube-apiserver.service

启动kube-apiserver

  1. systemctl daemon-reload
  2. systemctl enable kube-apiserver
  3. systemctl start kube-apiserver
  4. systemctl status kube-apiserver

配置和启动 kube-controller-manager

创建 kube-controller-manager的serivce配置文件

文件路径/usr/lib/systemd/system/kube-controller-manager.service

  1. [Unit]
  2. Description=Kubernetes Controller Manager
  3. Documentation=https://github.com/GoogleCloudPlatform/kubernetes
  4. [Service]
  5. EnvironmentFile=-/etc/kubernetes/config
  6. EnvironmentFile=-/etc/kubernetes/controller-manager
  7. ExecStart=/usr/local/bin/kube-controller-manager \
  8. $KUBE_LOGTOSTDERR \
  9. $KUBE_LOG_LEVEL \
  10. $KUBE_MASTER \
  11. $KUBE_CONTROLLER_MANAGER_ARGS
  12. Restart=on-failure
  13. LimitNOFILE=65536
  14. [Install]
  15. WantedBy=multi-user.target

配置文件/etc/kubernetes/controller-manager

  1. ###
  2. # The following values are used to configure the kubernetes controller-manager
  3. # defaults from config and apiserver should be adequate
  4. # Add your own!
  5. 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 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,否则:

    1. $ kubectl get componentstatuses
    2. NAME STATUS MESSAGE ERROR
    3. scheduler Unhealthy Get http://127.0.0.1:10251/healthz: dial tcp 127.0.0.1:10251: getsockopt: connection refused
    4. controller-manager Healthy ok
    5. etcd-2 Healthy {"health": "true"}
    6. etcd-0 Healthy {"health": "true"}
    7. etcd-1 Healthy {"health": "true"}

    如果有组件report unhealthy请参考:https://github.com/kubernetes-incubator/bootkube/issues/64

完整 unit 见 kube-controller-manager.service

启动 kube-controller-manager

  1. systemctl daemon-reload
  2. systemctl enable kube-controller-manager
  3. systemctl start kube-controller-manager

配置和启动 kube-scheduler

创建 kube-scheduler的serivce配置文件

文件路径/usr/lib/systemd/system/kube-scheduler.service

  1. [Unit]
  2. Description=Kubernetes Scheduler Plugin
  3. Documentation=https://github.com/GoogleCloudPlatform/kubernetes
  4. [Service]
  5. EnvironmentFile=-/etc/kubernetes/config
  6. EnvironmentFile=-/etc/kubernetes/scheduler
  7. ExecStart=/usr/local/bin/kube-scheduler \
  8. $KUBE_LOGTOSTDERR \
  9. $KUBE_LOG_LEVEL \
  10. $KUBE_MASTER \
  11. $KUBE_SCHEDULER_ARGS
  12. Restart=on-failure
  13. LimitNOFILE=65536
  14. [Install]
  15. WantedBy=multi-user.target

配置文件/etc/kubernetes/scheduler

  1. ###
  2. # kubernetes scheduler config
  3. # default config should be adequate
  4. # Add your own!
  5. KUBE_SCHEDULER_ARGS="--leader-elect=true --address=127.0.0.1"
  • --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;

完整 unit 见 kube-scheduler.service

启动 kube-scheduler

  1. systemctl daemon-reload
  2. systemctl enable kube-scheduler
  3. systemctl start kube-scheduler

验证 master 节点功能

  1. $ kubectl get componentstatuses
  2. NAME STATUS MESSAGE ERROR
  3. scheduler Healthy ok
  4. controller-manager Healthy ok
  5. etcd-0 Healthy {"health": "true"}
  6. etcd-1 Healthy {"health": "true"}
  7. etcd-2 Healthy {"health": "true"}