利用K8S技术栈打造个人私有云（连载之：K8S集群搭建）

最近被业务折腾的死去活来，实在没时间发帖，花了好多个晚上才写好这篇帖子，后续会加油的！

环境介绍

玩集群嘛，当然要搞几台机器做节点！无赖自己并没有性能很强劲的多余机器，在家里翻箱倒柜，找出了几台破旧的本子，试试看吧，与其垫桌脚不如拿出来遛遛弯…

总体环境安排如下图所示：

各部分简介如下：

Master节点 ( 一台08年买的Hedy笔记本 Centos7.3 64bit )

• docker
• etcd
• flannel
• kube-apiserver
• kube-scheduler
• kube-controller-manager

Slave节点 ( 一台二手Thinkpad T420s Centos7.3 64bit )

• docker
• flannel
• kubelet
• kube-proxy

Client节点（ 一台12年的Sony Vaio SVS13 Win7 Ultimate）

• 客户端嘛，毕竟甲方，不需要安装啥东西，有个ssh客户端能连到master和slave节点就OK

Docker镜像仓库

• 一般企业内部应用的话，其会搭建自己的docker registry，用作镜像仓库，我这里就直接用Docker Gub作为镜像仓库，自己不搭建了（其实主要是没机子啊！）

Wireless Router （雷猴子家的小米路由器3）

• 最好能穿墙，因为我家路由器放在客厅，但我实验是在卧室里做的啊！

各部分全部都是由wifi进行互联，我个人不太喜欢一大堆线绕来绕去

环境准备

1. 先设置master节点和所有slave节点的主机名

master上执行：

hostnamectl --static set-hostname  k8s-master

slave上执行：

hostnamectl --static set-hostname  k8s-node-1

2. 修改master和slave上的hosts

在master和slave的/etc/hosts文件中均加入以下内容：

192.168.31.166   k8s-master
192.168.31.166   etcd
192.168.31.166   registry
192.168.31.199   k8s-node-1

3. 关闭master和slave上的防火墙

systemctl disable firewalld.service
systemctl stop firewalld.service

部署Master节点

master节点需要安装以下组件：

• etcd
• flannel
• docker
• kubernets

下面按顺序阐述

1. etcd安装

• 安装命令：yum install etcd -y
• 编辑etcd的默认配置文件/etc/etcd/etcd.conf

# [member]
ETCD_NAME=master
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
#ETCD_WAL_DIR=""
#ETCD_SNAPSHOT_COUNT="10000"
#ETCD_HEARTBEAT_INTERVAL="100"
#ETCD_ELECTION_TIMEOUT="1000"
#ETCD_LISTEN_PEER_URLS="http://localhost:2380"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379,http://0.0.0.0:4001"
#ETCD_MAX_SNAPSHOTS="5"
#ETCD_MAX_WALS="5"
#ETCD_CORS=""
#
#[cluster]
#ETCD_INITIAL_ADVERTISE_PEER_URLS="http://localhost:2380"
# if you use different ETCD_NAME (e.g. test), set ETCD_INITIAL_CLUSTER value for this name, i.e. "test=http://..."
#ETCD_INITIAL_CLUSTER="default=http://localhost:2380"
#ETCD_INITIAL_CLUSTER_STATE="new"
#ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_ADVERTISE_CLIENT_URLS="http://etcd:2379,http://etcd:4001"
#ETCD_DISCOVERY=""
#ETCD_DISCOVERY_SRV=""
#ETCD_DISCOVERY_FALLBACK="proxy"
#ETCD_DISCOVERY_PROXY=""
#ETCD_STRICT_RECONFIG_CHECK="false"
#ETCD_AUTO_COMPACTION_RETENTION="0"
#ETCD_ENABLE_V2="true"
#
#[proxy]
#ETCD_PROXY="off"
#ETCD_PROXY_FAILURE_WAIT="5000"
#ETCD_PROXY_REFRESH_INTERVAL="30000"
#ETCD_PROXY_DIAL_TIMEOUT="1000"
#ETCD_PROXY_WRITE_TIMEOUT="5000"
#ETCD_PROXY_READ_TIMEOUT="0"
#
#[security]
#ETCD_CERT_FILE=""
#ETCD_KEY_FILE=""
#ETCD_CLIENT_CERT_AUTH="false"
#ETCD_TRUSTED_CA_FILE=""
#ETCD_AUTO_TLS="false"
#ETCD_PEER_CERT_FILE=""
#ETCD_PEER_KEY_FILE=""
#ETCD_PEER_CLIENT_CERT_AUTH="false"
#ETCD_PEER_TRUSTED_CA_FILE=""
#ETCD_PEER_AUTO_TLS="false"
#
#[logging]
#ETCD_DEBUG="false"
# examples for -log-package-levels etcdserver=WARNING,security=DEBUG
#ETCD_LOG_PACKAGE_LEVELS=""
#
#[profiling]
#ETCD_ENABLE_PPROF="false"
#ETCD_METRICS="basic"
#
#[auth]
#ETCD_AUTH_TOKEN="simple"

• 启动etcd并验证

首先启动etcd服务

systemctl start etcd // 启动etcd服务

再获取etcd的健康指标看看：

etcdctl -C http://etcd:2379 cluster-health
etcdctl -C http://etcd:4001 cluster-health

2. flannel安装

• 安装命令：yum install flannel
• 配置flannel：/etc/sysconfig/flanneld

# Flanneld configuration options  

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

• 配置etcd中关于flannel的key

etcdctl mk /atomic.io/network/config '{ "Network": "10.0.0.0/16" }'

• 启动flannel并设置开机自启

systemctl start flanneld.service
systemctl enable flanneld.service

3. docker安装

该部分网上教程太多了，主要步骤如下

• 安装命令：yum install docker -y
• 开启docker服务：service docker start
• 设置docker开启自启动：chkconfig docker on

4. kubernets安装

k8s的安装命令很简单，执行：

yum install kubernetes

但k8s需要配置的东西比较多，正如第一节“环境介绍”中提及的，毕竟master上需要运行以下组件：

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

下面详细阐述：

• 配置/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="--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://etcd: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=""

• 配置/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://k8s-master:8080"

• 启动k8s各个组件

systemctl start kube-apiserver.service
systemctl start kube-controller-manager.service
systemctl start kube-scheduler.service

• 设置k8s各组件开机启动

systemctl enable kube-apiserver.service
systemctl enable kube-controller-manager.service
systemctl enable kube-scheduler.service

部署Slave节点

slave节点需要安装以下组件：

• flannel
• docker
• kubernetes

下面按顺序阐述：

1. flannel安装

• 安装命令：yum install flannel
• 配置flannel：/etc/sysconfig/flanneld

# Flanneld configuration options  

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

• 启动flannel并设置开机自启

systemctl start flanneld.service
systemctl enable flanneld.service

2. docker安装

参考前文master节点上部署docker过程，此处不再赘述

3. kubernetes安装

安装命令：yum install kubernetes

不同于master节点，slave节点上需要运行kubernetes的如下组件：

• kubelet
• kubernets-proxy

下面详细阐述要配置的东西：

• 配置/etc/kubernetes/config

###
# 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://k8s-master:8080"

• 配置/etc/kubernetes/kubelet

###
# 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=k8s-node-1"

# location of the api-server
KUBELET_API_SERVER="--api-servers=http://k8s-master:8080"

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

# Add your own!
KUBELET_ARGS=""

• 启动kube服务

systemctl start kubelet.service
systemctl start kube-proxy.service

• 设置k8s组件开机自启

systemctl enable kubelet.service
systemctl enable kube-proxy.service

至此为止，k8s集群的搭建过程就完成了，下面来验证一下集群是否搭建成功了

验证集群状态

• 查看端点信息：kubectl get endpoints

• 查看集群信息：kubectl cluster-info

• 获取集群中的节点状态： kubectl get nodes

OK，节点已经就绪，可以在上面做实验了！

参考文献

• https://www.kubernetes.org.cn/