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-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；
注：
- 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。
$ 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
有两种下载方式，请注意下载对应的Kubernetes版本。
方式一
从 github release 页面 下载发布版 tarball，解压后再执行下载脚本
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
从 CHANGELOG页面 下载 client 或 server 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；
# 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
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
#
# 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://sz-pg-oam-docker-test-001.tendcloud.com:8080"
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：
###
## 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=sz-pg-oam-docker-test-001.tendcloud.com"
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-authBootstrap 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
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
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
我们启动每个组件后可以通过执行命令kubectl get componentstatuses，来查看各个组件的状态;
$ 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"}
- 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
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。
[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；
完整 unit 见 kube-scheduler.service
启动 kube-scheduler
systemctl daemon-reload
systemctl enable kube-scheduler
systemctl start kube-scheduler
验证 master 节点功能
$ 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"}