kubernetes 1.6 集羣實踐 （六）

kubernetes master 節點包含的組件

這三個組件須要部署在同一臺機器上,三者的功能緊密相關

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

同時只能有一個 kube-scheduler、kube-controller-manager 進程處於工做狀態，若是運行多個，則須要經過選舉產生一個 leader；

下載編譯好的二進制文件

在github尋找合適的連接下載：
https://github.com/kubernetes/kubernetes/releases
這個包裏面有master節點組件的所有文件
kubernetes-server-linux-amd64.tar.gz

拷貝到系統命令目錄下，並給予執行權限

$ 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 啓動文件

$ 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：

該配置文件同時被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 日誌設置

KUBE_LOG_LEVEL 日誌級別設置

KUBE_ALLOW_PRIV 是否運行運行特殊的Docker容器

KUBE_MASTER 主節點的地址，主要爲replication controller和scheduler，kube-proxy能夠順利找到apiserver，使用端口是本地主機端口由apiserver的--insecure-port 和--insecure-bind-address 定義

建立apiserver專用的配置文件/etc/kubernetes/apiserver內容爲

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 受權模式，拒絕未經過受權的請求；

kube-scheduler、kube-controller-manager 通常和 kube-apiserver 部署在同一臺機器上，它們使用非安全端口和 kube-apiserver通訊;

kubelet、kube-proxy、kubectl 部署在其它 Node 節點上，若是經過安全端口訪問 kube-apiserver，則必須先經過 TLS 證書認證，再經過 RBAC 受權；

kube-proxy、kubectl 經過在使用的證書裏指定相關的 User、Group 來達到經過 RBAC 受權的目的；

若是使用了 kubelet TLS Boostrap 機制，則不能再指定 --kubelet-certificate-authority、--kubelet-client-certificate 和 --kubelet-client-key 選項，不然後續

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 不能爲 127.0.0.1；

runtime-config配置爲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；

缺省狀況下 kubernetes 對象保存在 etcd /registry 路徑下，能夠經過 --etcd-prefix 參數進行調整；

--insecure-port 默認端口爲8080，--secure-port默認端口爲6443，--secure-port端口由node節點的kubelet或其餘工具調用。

建立kube-controller-manager的配置文件

建立systemd啓動文件

$ 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專用的配置文件/etc/kubernetes/controller-manager內容爲

$ 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 參數指定 Cluster 中 Service 的CIDR範圍，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-cidr 參數制定pod的網段

--cluster-signing-* 指定的證書和私鑰文件用來簽名爲 TLS BootStrap 建立的證書和私鑰；

--root-ca-file 用來對 kube-apiserver 證書進行校驗，指定該參數後，纔會在Pod 容器的 ServiceAccount 中放置該 CA 證書文件；

--address 值必須爲 127.0.0.1，由於當前 kube-apiserver 指望 scheduler 和 controller-manager 在同一臺機器

建立kube-scheduler的配置文件

建立systemd啓動文件

$ 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專用的配置文件/etc/kubernetes/scheduler內容爲

$ 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 值必須爲 127.0.0.1，由於當前 kube-apiserver 指望 scheduler 和 controller-manager 在同一臺機器

啓動master服務

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

嚴重master是否健康

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