部署master节点

kubernetes master 节点包含的组件:

  • kube-apiserver
  • kube-scheduler
  • kube-controller-master

目前这三个组件需要部署在同一机器上。

  • 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;

TLS证书文件

一下pem证书文件已经准备好了

[root@hz-k8s-cluster-n01 ssl]# cp -r admin*.pem ca*.pem kube-proxy*.pem kubernetes*.pem /etc/kubernetes/ssl/
[root@hz-k8s-cluster-n01 ssl]# 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

下载最新版本的二进制文件

wget https://github.com/kubernetes/kubernetes/releases/download/v1.9.0/kubernetes.tar.gz
tar -xzvf kubernetes-server-linux-amd64.tar.gz
cd kubernetes
tar -xzvf kubernetes-src.tar.gz

将二进制文件拷贝到指定路径

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:

[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文件的内容为:

###
# kubernetes system config

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://10.80.231.151:8080"

注意:该配置文件同时被kube-apiserverkube-controller-managerkube-schedulerkubeletkube-proxy使用(node节点需要)。

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

###
## 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="--advertise-address=10.80.231.151 --bind-address=10.80.231.151 --insecure-bind-address=10.80.231.151"
#
## 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://10.80.231.151:2379,https://10.80.230.57:2379,https://10.81.50.223:2379"
#
## 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=Node,RBAC --runtime-config=rbac.authorization.k8s.io/v1beta1 --kubelet-https=true --enable-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"
  • 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=Node,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

启动kube-apiserver

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

[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

###
# 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 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,kube-apiserver 期望 scheduler 和 controller-manager 在同一台机器;

启动 kube-controller-manager

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

查看各组件的状态

$ 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"}

配置和启动 kube-scheduler

创建kube-scheduler的service配置文件

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

[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

###
# kubernetes scheduler config
# default config should be adequate
# Add your own!
KUBE_SCHEDULER_ARGS="--leader-elect=true --address=127.0.0.1"
  • –address 值必须为 127.0.0.1,因为当前 kube-apiserver 期望 scheduler 和 controller-manager 在同一台机器;

启动 kube-scheduler

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

验证master 节点功能

[root@hz-k8s-cluster-n01 ~]# 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"}

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