CentOS7 快速安装 kubernetes 集群 (单工作节点)

CentOS7 安装 kubernetes 集群 (单工作节点)

本文档旨在快速部署与体验

kubernetes

,只运行一个工作节点，如果要运行多个工作节点，则还需要考虑一些网络问题

一、基础配置（两端都要）

两台服务器：

master1 是控制节点，运行

kube-apiserver

,

kube-controller-manager

,

kube-scheduler

和

etcd

四个服务

node1 是工作节点，实际运行容器的地方，运行

kubelet

,

proxy

,

cadvisor

和

docker

服务说明：

etcd 是一个高可用的

Key/Value

存储系统,主要用于分享配置和服务发现。

cAdvisor 是谷歌公司用来分析运行中的

Docker

容器的资源占用以及性能特性的工具。

1.1 编辑

hosts

文件

# vim /etc/hosts
192.168.100.166 master1
192.168.100.167 node1

1.2 关闭防火墙

# systemctl disable iptables-services firewalld
# systemctl stop iptables-services firewalld

因为

docker

与这两种防火墙的兼容性不好

1.3 配置

YUM

源

# vi /etc/yum.repos.d/virt7-docker-common-release.repo
[virt7-docker-common-release]
name=virt7-docker-common-release
baseurl=http://cbs.centos.org/repos/virt7-docker-common-release/x86_64/os/
gpgcheck=0

1.4 安装程序包

# yum -y install --enablerepo=virt7-docker-common-release kubernetes etcd

1.5 编辑配置文件

/etc/kubernetes/config

# Comma separated list of nodes in the etcd cluster
KUBE_ETCD_SERVERS="--etcd-servers=http://master1:2379"

# 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 replication controller and scheduler find the kube-apiserver
KUBE_MASTER="--master=http://master1:8080"

二、配置

master1

节点

2.1 编辑

/etc/etcd/etcd.conf

# [member]
ETCD_NAME=default
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"

#[cluster]
ETCD_ADVERTISE_CLIENT_URLS="http://0.0.0.0:2379"

2.2 编辑

/etc/kubernetes/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 kubelets listen on
KUBELET_PORT="--kubelet-port=10250"

# Address range to use for services
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"

# Add your own!
KUBE_API_ARGS="--secure-port=0"

2.3 启动服务

for SERVICES in etcd kube-apiserver kube-controller-manager kube-scheduler; do
systemctl restart $SERVICES
systemctl enable $SERVICES
systemctl status $SERVICES
done

三、配置

node1

节点

3.1 编辑

/etc/kubernetes/kubelet

# The address for the info server to serve on
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=node1"

# Location of the api-server
KUBELET_API_SERVER="--api-servers=http://master1:8080"

# Add your own!
KUBELET_ARGS=""

3.2 启动服务

for SERVICES in kube-proxy kubelet docker; do
systemctl restart $SERVICES
systemctl enable $SERVICES
systemctl status $SERVICES
done

四、启动一个

POD

4.1 查看可用节点

[root@master1 ~]# kubectl get nodes
NAME      STATUS     AGE
node1     Ready      4h

如果状态是

Ready

则表示前面的安装基本都是OK的，可以使用了

4.2 定义一个

pod

以

nginx

服务器为例

[root@master1 ~]# mkdir pods
[root@master1 ~]# cd pods
[root@master1 pods]# vim pod-nginx.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx:latest
ports:
- containerPort: 80

4.3 启动这个

pod

[root@master1 pods]# kubectl create -f pod-nginx.yaml
pod "nginx" created

4.4 查看状态

[root@master1 pods]# kubectl get pods
NAME      READY     STATUS              RESTARTS   AGE
nginx     0/1       ContainerCreating   0          2s
[root@master1 pods]# kubectl get pods
NAME      READY     STATUS    RESTARTS   AGE
nginx     1/1       Running   0          14s
[root@master1 pods]# kubectl get pods -o wide
NAME      READY     STATUS    RESTARTS   AGE       NODE
nginx     1/1       Running   0          1m        node1

状态为

Running

表示

pod

已经正常启动

在这里遇到了第一个坑，由于国内访问不了

gcr.io

，导致

pod

一直处于

ContainerCreating

状态，解决的办法是在

node1

节点，从

docker

官方下载

pause

镜像，然后打上

gcr.io

的标签。

[root@node1 ~]# docker pull kubernetes/pause
[root@node1 ~]# docker tag kubernetes/pause gcr.io/google_containers/pause:2.0
[root@node1 ~]# docker images
REPOSITORY                       TAG                 IMAGE ID            CREATED             SIZE
docker.io/kubernetes/pause       latest              f9d5de079539        2 years ago         239.8 kB
gcr.io/google_containers/pause   2.0                 f9d5de079539        2 years ago         239.8 kB

4.5 尽情的玩耍吧（请忽略）

[root@master1 pods]# kubectl get pods --all-namespaces -o wide
NAMESPACE   NAME      READY     STATUS    RESTARTS   AGE       NODE
default     httpd     1/1       Running   0          1h        node1
default     nginx     1/1       Running   0          2m        node1
[root@master1 pods]#
[root@master1 pods]# kubectl describe pod nginx
Name:       nginx
Namespace:  default
Node:       node1/192.168.100.167
Start Time: Mon, 12 Sep 2016 16:10:03 +0800
Labels:     <none>
Status:     Running
IP:     172.17.0.2
Controllers:    <none>
Containers:
nginx:
Container ID:   docker://c19aa6d59d6c0d3f6795fe7b93bc9f7b55b0653987909b5a28b2489ccf8ff451
Image:      nginx:latest
Image ID:       docker://sha256:4efb2fcdb1ab05fb03c9435234343c1cc65289eeb016be86193e88d3a5d84f6b
Port:       80/TCP
QoS Tier:
cpu:      BestEffort
memory:       BestEffort
State:      Running
Started:      Mon, 12 Sep 2016 16:10:11 +0800
Ready:      True
Restart Count:  0
Environment Variables:
Conditions:
Type      Status
Ready     True
No volumes.
No events.

[root@node1 ~]# docker ps
CONTAINER ID        IMAGE                                COMMAND                  CREATED             STATUS              PORTS               NAMES
c19aa6d59d6c        nginx:latest                         "nginx -g 'daemon off"   About an hour ago   Up About an hour                        k8s_nginx.538ff56_nginx_default_4ea138f0-78c0-11e6-afbf-000c29e23365_ced077ea
1c5f8babd16a        gcr.io/google_containers/pause:2.0   "/pause"                 About an hour ago   Up About an hour                        k8s_POD.cf58006d_nginx_default_4ea138f0-78c0-11e6-afbf-000c29e23365_3f2bcf72
c757ee7d86e8        httpd:latest                         "httpd-foreground"       3 hours ago         Up 3 hours                              k8s_httpd.6541ffbe_httpd_default_c3b73c62-78b2-11e6-afbf-000c29e23365_549c4b76
65a441b8787c        gcr.io/google_containers/pause:2.0   "/pause"                 3 hours ago         Up 3 hours                              k8s_POD.364e00d5_httpd_default_c3b73c62-78b2-11e6-afbf-000c29e23365_047c5258