kubenetes 集群二进制安装之master安装部署 – 21运维
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kubenetes 集群二进制安装之master安装部署

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kubernetes master 节点包含的组件:
kube-apiserver :集群核心,集群API接口、集群各个组件通信的中枢;集群安全控制;
kube-scheduler: 集群调度器 ,根据node负载(cpu、内存、存储、策略等)将pod分配到合适node。
kube-controller-manager:集群状态管理器 。当集群状态与集群期望值不同时,该控制器会根据已有策略将其恢复到指定状态。
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;
注意:集群只能有一个 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

说明:当前master没有做高可用部署,后边优化补全高可用方案。
前期首先进行kubenetes v1.12.2相关服务命令部署
将下载的https://dl.k8s.io/v1.12.2/kubernetes-server-linux-amd64.tar.gz 解压(之前已经解压过),将服务相关的命令全都拷贝到/usr/local/bin/目录

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

一,配置和启动 kube-apiserver
1,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

2,/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://10.1.14.21:8080"

这个配置文件是全局配置文件,上述有提示:该配置文件同时被kube-apiserver、kube-controller-manager、kube-scheduler、kubelet、kube-proxy使用。

3,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=10.1.14.21 --bind-address=10.1.14.21 --insecure-bind-address=10.1.14.21"
#
## 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://10.1.14.23:2379,https://10.1.14.24:2379,https://10.1.14.22:2379"
#
## 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 --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"

配置文件说明:
–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 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

4,启动kube-apiserver

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

二,配置和启动 kube-controller-manager

1,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

2,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"

说明:
–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;

3,启动 kube-controller-manager

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

4,我们启动每个组件后可以通过执行命令kubectl get cs,来查看各个组件的状态;

[[email protected] kubernetes]# kubectl get cs
NAME                 STATUS      MESSAGE                                                                                     ERROR
scheduler            Unhealthy   Get http://127.0.0.1:10251/healthz: dial tcp 127.0.0.1:10251: connect: connection refused   
controller-manager   Healthy     ok                                                                                          
etcd-1               Healthy     {"health": "true"}                                                                          
etcd-2               Healthy     {"health": "true"}                                                                          
etcd-0               Healthy     {"health": "true"}  

查看kube-controller-manager正常,下边配置kube-scheduler

三,配置和启动 kube-scheduler
1,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

2,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"

说明:–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;
3,启动kube-scheduler

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

4,验证 master 节点功能

[[email protected] kubernetes]# kubectl get cs                    
NAME                 STATUS    MESSAGE              ERROR
controller-manager   Healthy   ok                   
scheduler            Healthy   ok                   
etcd-1               Healthy   {"health": "true"}   
etcd-0               Healthy   {"health": "true"}   
etcd-2               Healthy   {"health": "true"}  


四,其他master节点部署
线上环境不止一个master,如果要高可用,一般都会是多个。 配置完一台master以后,其他master只需要把kube*二进制命令, kubectl kubeconfig 、/etc/kubenetes/配置文件 以及几个service配置文件(搞成enable)弄过来就行了。
当然高可用一般我们设置一个域名解析道slb或者alb,需要注意一点就是每个master节点最好将这个域名定向到master本地ip,免得出现回源回路情况。

参考文章:部署master节点

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