CentOS7搭建k8s集群
一.机器信息
[root@kube-gmg-03-master-1 ~]# uname -a
Linux kube-gmg-03-master-1 3.10.0-957.el7.x86_64 #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
[root@kube-gmg-03-master-1 ~]# cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)
二、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 |
10.255.61.1 |
|
Node1 |
K8s-node-1 |
10.255.61.2 |
|
Node2 |
K8s-node-2 |
10.255.61.3 |
三、设置三台机器的主机名
Master上执行：
hostnamectl --static set-hostname k8s-master
Node1上执行：
hostnamectl --static set-hostname k8s-node-1
Node2上执行：
hostnamectl --static set-hostname k8s-node-2
四、设置hosts
三台机器均执行如下命令：
echo '10.255.61.1 k8s-master 10.255.61.1 etcd 10.255.61.1 registry 10.255.61.2 k8s-node-1 10.255.61.3 k8s-node-2' >> /etc/hosts
五、关闭三台机器上的防火墙
systemctl disable firewalld.service
systemctl stop firewalld.service
六、三台机器部署etcd
k8s运行依赖etcd，需要先部署etcd，本文采用yum方式安装：
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：
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（先启动master的etcd）
扩展：Etcd集群部署参见——http://www.cnblogs.com/zhenyuyaodidiao/p/6237019.html
七、部署master
7.1 安装docker
yum install docker -y
配置Docker配置文件，使其允许从registry中拉取镜像。
vim /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
systemctl enable docker.service systemctl start docker
7.2 安装kubernets
yum install kubernetes -y
7.3 配置并启动kubernetes
在kubernetes master上需要安装运行以下组件：
Kubernets API Server
Kubernets Controller Manager
Kubernets Scheduler
7.4 相应的要更改以下几个配置中带颜色部分信息：
### # 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=""
###
# 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"
7.5 启动服务并设置开机自启动，运行如下命令
systemctl enable kube-apiserver.service systemctl start kube-apiserver.service systemctl enable kube-controller-manager.service systemctl start kube-controller-manager.service systemctl enable kube-scheduler.service systemctl start kube-scheduler.service
八、部署node节点
8.1 参考7.1安装docker 参考7.2安装kubernets
8.2 node节点启动kubernets
在kubernetes node上需要运行以下组件：
Kubelet
Kubernets Proxy
8.2.1 配置文件
###
# 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"
### # 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=""
8.3 启动服务并设置开机自启动
systemctl enable kubelet.service systemctl start kubelet.service systemctl enable kube-proxy.service systemctl start kube-proxy.service
8.4 查看状态
在master上查看集群中节点及节点状态
NAME STATUS AGE k8s-node-1 Ready 3m k8s-node-2 Ready 16s $ 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。
九、创建覆盖网络——Flannel
9.1 安装Flannel
在master、node上均执行如下命令，进行安装
[root@k8s-master ~]# yum install flannel
9.2 配置Flannel
master、node上均编辑/etc/sysconfig/flanneld，修改红色部分
# 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=""
9.3 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" }
9.4 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
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
感谢https://www.cnblogs.com/zhenyuyaodidiao/p/6500830.html
结束！
