kubernetes 1.6 集群实践 （六）

kubernetes master 节点包含的组件

这三个组件须要部署在同一台机器上,三者的功能紧密相关

• kube-apiserver
• kube-scheduler
• kube-controller-manager

同时只能有一个 kube-scheduler、kube-controller-manager 进程处于工做状态，若是运行多个，则须要经过选举产生一个 leader；

下载编译好的二进制文件

在github寻找合适的连接下载：
https://github.com/kubernetes/kubernetes/releases
这个包里面有master节点组件的所有文件
kubernetes-server-linux-amd64.tar.gz

拷贝到系统命令目录下，并给予执行权限

$ tar xf kubernetes-server-linux-amd64.tar.gz
$ cd kubernetes/server/bin
$ cp {kube-apiserver,kube-controller-manager,kube-scheduler,kubectl,kube-proxy,kubelet} /usr/bin/
$ chmod +x /usr/bin/kube*

建立 kube-apiserver的配置文件

建立systemd 启动文件

$ cat > /usr/lib/systemd/system/kube-apiserver.service << EOF
[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/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
EOF

建立配置文件 /etc/kubernetes/config文件配置以下：

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

cat > /etc/kubernetes/config << EOF
###
# 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://192.168.19.101:8080"
EOF

KUBE_LOGTOSTDERR 日志设置

KUBE_LOG_LEVEL 日志级别设置

KUBE_ALLOW_PRIV 是否运行运行特殊的Docker容器

KUBE_MASTER 主节点的地址，主要为replication controller和scheduler，kube-proxy能够顺利找到apiserver，使用端口是本地主机端口由apiserver的--insecure-port 和--insecure-bind-address 定义

建立apiserver专用的配置文件/etc/kubernetes/apiserver内容为

cat > /etc/kubernetes/apiserver << EOF
###
## 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=192.168.19.101 --bind-address=192.168.19.101 --insecure-bind-address=192.168.19.101"
#
## 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://192.168.19.101:2379,https://192.168.19.102:2379,https://192.168.19.103:2379"
#
## 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"
EOF

--authorization-mode=RBAC 指定在安全端口使用 RBAC 受权模式，拒绝未经过受权的请求；

kube-scheduler、kube-controller-manager 通常和 kube-apiserver 部署在同一台机器上，它们使用非安全端口和 kube-apiserver通讯;

kubelet、kube-proxy、kubectl 部署在其它 Node 节点上，若是经过安全端口访问 kube-apiserver，则必须先经过 TLS 证书认证，再经过 RBAC 受权；

kube-proxy、kubectl 经过在使用的证书里指定相关的 User、Group 来达到经过 RBAC 受权的目的；

若是使用了 kubelet TLS Boostrap 机制，则不能再指定 --kubelet-certificate-authority、--kubelet-client-certificate 和 --kubelet-client-key 选项，不然后续

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；

缺省状况下 kubernetes 对象保存在 etcd /registry 路径下，能够经过 --etcd-prefix 参数进行调整；

--insecure-port 默认端口为8080，--secure-port默认端口为6443，--secure-port端口由node节点的kubelet或其余工具调用。

建立kube-controller-manager的配置文件

建立systemd启动文件

$ cat >/usr/lib/systemd/system/kube-controller-manager.service << EOF
Description=Kubernetes Controller Manager
Documentation=https://github.com/GoogleCloudPlatform/kubernetes

[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/controller-manager
ExecStart=/usr/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
EOF

建立kube-controller-manager专用的配置文件/etc/kubernetes/controller-manager内容为

$ cat >/etc/kubernetes/controller-manager <<EOF
###
# 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-cidr=10.250.0.0/16  --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"
EOF

--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-cidr 参数制定pod的网段

--cluster-signing-* 指定的证书和私钥文件用来签名为 TLS BootStrap 建立的证书和私钥；

--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，由于当前 kube-apiserver 指望 scheduler 和 controller-manager 在同一台机器

建立kube-scheduler的配置文件

建立systemd启动文件

$ cat > /usr/lib/systemd/system/kube-scheduler.service << EOF
[Unit]
Description=Kubernetes Scheduler Plugin
Documentation=https://github.com/GoogleCloudPlatform/kubernetes

[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/scheduler
ExecStart=/usr/bin/kube-scheduler \
            \$KUBE_LOGTOSTDERR \
            \$KUBE_LOG_LEVEL \
            \$KUBE_MASTER \
            \$KUBE_SCHEDULER_ARGS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

建立kube-scheduler专用的配置文件/etc/kubernetes/scheduler内容为

$ cat > /etc/kubernetes/scheduler << EOF
###
# kubernetes scheduler config

# default config should be adequate

# Add your own!
KUBE_SCHEDULER_ARGS="--leader-elect=true --address=127.0.0.1"
EOF

--address 值必须为 127.0.0.1，由于当前 kube-apiserver 指望 scheduler 和 controller-manager 在同一台机器

启动master服务

$ systemctl daemon-reload && systemctl start kube-apiserver && systemctl start kube-controller-manager && systemctl start kube-scheduler

严重master是否健康

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