K8s集群安装和检查（经验分享）

一、组件方式检查

1. Master节点：

root>> kubectl get cs

2. Node 节点：

无

 二、服务方式检查

1. Master 节点：

root>> systemctl status etcd
root>> systemctl status kube-apiserver
root>> systemctl status kube-controller-manager
root>> systemctl status kube-scheduler

2. Node 节点

root>> systemctl status flanneld
root>> systemctl status kube-proxy
root>> systemctl status kubelet
root>> systemctl status docker

三、进程方式检查

1. Master 节点：

root>> ps -ef | grep etcd

root>> yum list installed | grep kube

2. Node 节点：

root>> ps -ef | grep flannel

root>> ps -ef | grep kube

四、安装包方式检查

1. Master 节点：

root>> yum list installed | grep etcd

root>> yum list installed | grep kube

2. Node 节点：

root>> yum list installed | grep flannel

root>> yum list installed | grep kube

五，附上第一次安装k8s集群失败后，后面重新安装k8s的一些环境重置的命令。

5.1 Master 节点
1. 卸载之前组件

[root@CNT7XDCK01 ~]# yum list installed | grep kube  #首先查询组件
kubernetes-client.x86_64                1.5.2-0.7.git269f928.el7       @extras  
kubernetes-master.x86_64                1.5.2-0.7.git269f928.el7       @extras  
[root@CNT7XDCK01 ~]# yum remove -y kubernetes-client.x86_64
[root@CNT7XDCK01 ~]# yum remove -y kubernetes-master.x86_64

2. 重新安装组件
[root@CNT7XDCK01 ~]# yum -y install etcd
[root@CNT7XDCK01 ~]# yum -y install kubernetes-master

3. 配置相关kube的配置文件

编辑/etc/etcd/etcd.conf文件

ETCD_NAME="default"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
ETCD_ADVERTISE_CLIENT_URLS="http://localhost:2379"

编辑/etc/kubernetes/apiserver文件

###
# 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=0.0.0.0"

# 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=http://127.0.0.1:2379"

# 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=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota"
KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"

# Add your own!
KUBE_API_ARGS=""

4. 重新注册/启动/检查：组件的系统服务
[root@CNT7XDCK01 ~]# systemctl enable etcd
[root@CNT7XDCK01 ~]# systemctl enable kube-apiserver
[root@CNT7XDCK01 ~]# systemctl enable kube-controller-manager
[root@CNT7XDCK01 ~]# systemctl enable kube-scheduler

[root@CNT7XDCK01 ~]# systemctl restart etcd
[root@CNT7XDCK01 ~]# systemctl restart kube-apiserver
[root@CNT7XDCK01 ~]# systemctl restart kube-controller-manager
[root@CNT7XDCK01 ~]# systemctl restart kube-scheduler

[root@CNT7XDCK01 ~]# systemctl status etcd
[root@CNT7XDCK01 ~]# systemctl status kube-apiserver
[root@CNT7XDCK01 ~]# systemctl status kube-controller-manager
[root@CNT7XDCK01 ~]# systemctl status kube-scheduler

====================================================================

5.2 Node 节点
1. 卸载之前组件

[root@CNT7XDCK02 ~]# yum list installed | grep kube
kubernetes-client.x86_64             1.5.2-0.7.git269f928.el7          @extras  
kubernetes-node.x86_64               1.5.2-0.7.git269f928.el7          @extras
[root@CNT7XDCK02 ~]# yum remove -y kubernetes-client.x86_64
[root@CNT7XDCK02 ~]# yum remove -y kubernetes-node.x86_64

2. 重新安装组件
[root@CNT7XDCK02 ~]# yum -y install flannel
[root@CNT7XDCK02 ~]# yum -y install kubernetes-node

3. 配置相关kube的配置文件

修改/etc/sysconfig/flanneld文件

# Flanneld configuration options  

# etcd url location.  Point this to the server where etcd runs
FLANNEL_ETCD_ENDPOINTS="http://192.168.3.96:2379"

# etcd config key.  This is the configuration key that flannel queries
# For address range assignment
FLANNEL_ETCD_PREFIX="/atomic.io/network"

# Any additional options that you want to pass
#FLANNEL_OPTIONS=""

修改/etc/kubernetes/config文件

###
# 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=false"

# How the controller-manager, scheduler, and proxy find the apiserver
KUBE_MASTER="--master=http://192.168.3.96:8080"

修改/etc/kubernetes/kubelet文件

###
# kubernetes kubelet (minion) config

# The address for the info server to serve on (set to 0.0.0.0 or "" for all interfaces)
KUBELET_ADDRESS="--address=0.0.0.0"

# The port for the info server to serve on
KUBELET_PORT="--port=10250"

# You may leave this blank to use the actual hostname
KUBELET_HOSTNAME="--hostname-override=192.168.3.97" # 这里是node机器的IP

# location of the api-server
KUBELET_API_SERVER="--api-servers=http://192.168.3.96:8080" # 这里是master机器的IP

# pod infrastructure container
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"

# Add your own!
KUBELET_ARGS=""

4. 重新注册/启动/检查：组件的系统服务
[root@CNT7XDCK02 ~]# systemctl enable flanneld
[root@CNT7XDCK02 ~]# systemctl enable kube-proxy
[root@CNT7XDCK02 ~]# systemctl enable kubelet
[root@CNT7XDCK02 ~]# systemctl enable docker

[root@CNT7XDCK02 ~]# systemctl restart flanneld
[root@CNT7XDCK02 ~]# systemctl restart kube-proxy
[root@CNT7XDCK02 ~]# systemctl restart kubelet
[root@CNT7XDCK02 ~]# systemctl restart docker

[root@CNT7XDCK02 ~]# systemctl status flanneld
[root@CNT7XDCK02 ~]# systemctl status kube-proxy
[root@CNT7XDCK02 ~]# systemctl status kubelet
[root@CNT7XDCK02 ~]# systemctl status docker

六、最后，在Master机器，查看K8s安装结果

[root@CNT7XDCK01 ~]# kubectl get nodes
NAME            STATUS    AGE
192.168.3.100   Ready     35d
192.168.3.97    Ready     35d
192.168.3.98    Ready     35d
192.168.3.99    Ready     35d

如下，可以看到master拥有四个node节点机器，状态是Ready正常的。