Centos7部署Kubernetes集群
目录贴：Kubernetes学习系列
1、环境介绍及准备：
1.1 物理机操作系统
物理机操作系统采用Centos7.3 64位，细节如下。
[root@localhost ~]# uname -a Linux localhost.localdomain 3.10.0-514.6.1.el7.x86_64 #1 SMP Wed Jan 18 13:06:36 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux [root@localhost ~]# cat /etc/redhat-release CentOS Linux release 7.3.1611 (Core)
1.2 主机信息
本文准备了三台机器用于部署k8s的运行环境，细节如下：
|
节点及功能 |
主机名 |
IP |
|
Master、etcd、registry |
K8s-master |
10.0.251.148 |
|
Node1 |
K8s-node-1 |
10.0.251.153 |
|
Node2 |
K8s-node-2 |
10.0.251.155 |
设置三台机器的主机名：
Master上执行：
[root@localhost ~]# hostnamectl --static set-hostname k8s-master
Node1上执行：
[root@localhost ~]# hostnamectl --static set-hostname k8s-node-1
Node2上执行：
[root@localhost ~]# hostnamectl --static set-hostname k8s-node-2
在三台机器上设置hosts，均执行如下命令：
echo '10.0.251.148 k8s-master 10.0.251.148 etcd 10.0.251.148 registry 10.0.251.153 k8s-node-1 10.0.251.155 k8s-node-2' >> /etc/hosts
1.3 关闭三台机器上的防火墙
systemctl disable firewalld.service
systemctl stop firewalld.service
2、部署etcd
k8s运行依赖etcd，需要先部署etcd，本文采用yum方式安装：
[root@localhost ~]# yum install etcd -y
yum安装的etcd默认配置文件在/etc/etcd/etcd.conf。编辑配置文件，更改以下带颜色部分信息：
[root@localhost ~]# vi /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://0.0.0.0:2380" 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=""
启动并验证状态
[root@localhost ~]# systemctl start etcd [root@localhost ~]# etcdctl set testdir/testkey0 0 0 [root@localhost ~]# etcdctl get testdir/testkey0 0 [root@localhost ~]# etcdctl -C http://etcd:4001 cluster-health member 8e9e05c52164694d is healthy: got healthy result from http://0.0.0.0:2379 cluster is healthy [root@localhost ~]# etcdctl -C http://etcd:2379 cluster-health member 8e9e05c52164694d is healthy: got healthy result from http://0.0.0.0:2379 cluster is healthy
扩展：Etcd集群部署参见——http://www.cnblogs.com/zhenyuyaodidiao/p/6237019.html
3、部署master
3.1 安装Docker
[root@k8s-master ~]# yum install docker
配置Docker配置文件，使其允许从registry中拉取镜像。
[root@k8s-master ~]# vim /etc/sysconfig/docker # /etc/sysconfig/docker # Modify these options if you want to change the way the docker daemon runs OPTIONS='--selinux-enabled --log-driver=journald --signature-verification=false' if [ -z "${DOCKER_CERT_PATH}" ]; then DOCKER_CERT_PATH=/etc/docker fi OPTIONS='--insecure-registry registry:5000'
设置开机自启动并开启服务
[root@k8s-master ~]# chkconfig docker on
[root@k8s-master ~]# service docker start
3.2 安装kubernets
[root@k8s-master ~]# yum install kubernetes
3.3 配置并启动kubernetes
在kubernetes master上需要运行以下组件：
Kubernets API Server
Kubernets Controller Manager
Kubernets Scheduler
相应的要更改以下几个配置中带颜色部分信息：
3.3.1 /etc/kubernetes/apiserver
[root@k8s-master ~]# vim /etc/kubernetes/apiserver ### # 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://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=""
3.3.2 /etc/kubernetes/config
[root@k8s-master ~]# vim /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"
启动服务并设置开机自启动
[root@k8s-master ~]# systemctl enable kube-apiserver.service [root@k8s-master ~]# systemctl start kube-apiserver.service [root@k8s-master ~]# systemctl enable kube-controller-manager.service [root@k8s-master ~]# systemctl start kube-controller-manager.service [root@k8s-master ~]# systemctl enable kube-scheduler.service [root@k8s-master ~]# systemctl start kube-scheduler.service
4、部署node
4.1 安装docker
参见3.1
4.2 安装kubernets
参见3.2
4.3 配置并启动kubernetes
在kubernetes node上需要运行以下组件：
Kubelet
Kubernets Proxy
相应的要更改以下几个配置文中带颜色部分信息：
4.3.1 /etc/kubernetes/config
[root@K8s-node-1 ~]# vim /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"
4.3.2 /etc/kubernetes/kubelet
[root@K8s-node-1 ~]# vim /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=""
启动服务并设置开机自启动
[root@k8s-master ~]# systemctl enable kubelet.service [root@k8s-master ~]# systemctl start kubelet.service [root@k8s-master ~]# systemctl enable kube-proxy.service [root@k8s-master ~]# systemctl start kube-proxy.service
4.4 查看状态
在master上查看集群中节点及节点状态
[root@k8s-master ~]# kubectl -s http://k8s-master:8080 get node NAME STATUS AGE k8s-node-1 Ready 3m k8s-node-2 Ready 16s [root@k8s-master ~]# kubectl get nodes NAME STATUS AGE k8s-node-1 Ready 3m k8s-node-2 Ready 43s
至此，已经搭建了一个kubernetes集群，但目前该集群还不能很好的工作，请继续后续的步骤。
5、创建覆盖网络——Flannel
5.1 安装Flannel
在master、node上均执行如下命令，进行安装
[root@k8s-master ~]# yum install flannel
版本为0.0.5
5.2 配置Flannel
master、node上均编辑/etc/sysconfig/flanneld，修改红色部分
[root@k8s-master ~]# vi /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=""
5.3 配置etcd中关于flannel的key
Flannel使用Etcd进行配置，来保证多个Flannel实例之间的配置一致性，所以需要在etcd上进行如下配置：（‘/atomic.io/network/config’这个key与上文/etc/sysconfig/flannel中的配置项FLANNEL_ETCD_PREFIX是相对应的，错误的话启动就会出错）
[root@k8s-master ~]# etcdctl mk /atomic.io/network/config '{ "Network": "10.0.0.0/16" }' { "Network": "10.0.0.0/16" }
5.4 启动
启动Flannel之后，需要依次重启docker、kubernete。
在master执行：
systemctl enable flanneld.service systemctl start flanneld.service service docker restart systemctl restart kube-apiserver.service systemctl restart kube-controller-manager.service systemctl restart kube-scheduler.service
在node上执行：
systemctl enable flanneld.service
systemctl start flanneld.service
service docker restart
systemctl restart kubelet.service
systemctl restart kube-proxy.service
以上文章均为我个人通过读书+测试环境验证，自己总结出来的。原创。
涉及到的书籍——Kubernetes实战、Kubernetes权威指南：从Docker到Kubernetes实践全接触、每天5分钟玩转Docker容器技术 、Docker容器：利用Kubernetes、Flannel、Cockpit和Atomic构建和部署
