K8S入门系列之集群yum安装-->初试篇(一)

kubernetes master 节点包含的组件：

1、kube-apiserver ：集群核心，集群API接口、集群各个组件通信的中枢；集群安全控制；
2、kube-scheduler： 集群调度器 ，根据node负载(cpu、内存、存储、策略等)将pod分配到合适node。
3、kube-controller-manager：集群状态管理器 。当集群状态与集群期望值不同时，该控制器会根据已有策略将其恢复到指定状态。
kube-scheduler、kube-controller-manager 和 kube-apiserver 三者的功能紧密相关，前需要部署在同一台机器上。
4、etcd 一个高可用的K/V键值对存储和服务发现系统

注意：集群只能有一个 kube-scheduler、kube-controller-manager 进程处于工作状态，如果运行多个，则需要通过选举产生一个 leader

kubernetes node 节点包含的组件：

1、kubelet 在Node节点上按照配置文件中定义的容器规格启动容器
2、kube-proxy 提供网络代理服务，将service与pod打通。
3、flannel 实现夸主机的容器网络的通信
4、docker 这个就不用说了！

安装环境准备：

1、关闭防火墙服务，避免与docker容器的防火墙规则冲突。

[root@localhost ~]# systemctl disable firewalld
[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)

2、关闭selinux
修改/etc/selinux/config为SELINUX=disabled

[root@localhost ~]# getenforce 
Disabled

一、master安装部署

1、安装master组件：

kubernetes-master （包含：kube-apiserver、kube-scheduler、kube-controller-manager）
etcd

[root@localhost ~]# yum install etcd kubernetes-master -y

2、编辑/etc/etcd/etcd.conf文件

ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"        #监听所有IP的2379端口
ETCD_NAME="default"        #etcd名字，没有高可用只有一台的话可用默认！
ETCD_ADVERTISE_CLIENT_URLS="http://localhost:2379"      

3、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://192.168.1.201:2379"

# 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,ResourceQuota"

# Add your own!
KUBE_API_ARGS=""
                                                  

4、/etc/kubernetes/config

KUBE_MASTER="--master=http://127.0.0.1:8080" 默认指向本机不需修改！

启动etcd、kube-apiserver、kube-controller-manager、kube-scheduler等服务，并设置开机启动。

5、在etcd中定义flannel网络

[root@master01 ~]# etcdctl mk /atomic.io/network/config '{"Network":"172.80.0.0/16"}'

二、node安装部署 (适用所有node)

1，安装flannel和kubernetes-node

[root@node01 ~]# yum install kubernetes-node flannel -y 

2、为flannel网络指定etcd服务，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://192.168.1.201:2379"    # 192.168.1.201为etcd所在服务器的IP（可设置多个--高可用）！

# 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=""

3、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://192.168.1,201:8080"        #192.168.1.201为master所在服务器的IP！

4、修改node节点配置文件/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=192.168.1.202"        #192.168.1.202为本机node的IP！

# location of the api-server
KUBELET_API_SERVER="--api-servers=http://192.168.1.201:8080"    #192.168.1.201为apiserver所在服务器的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=""

5、启动flanneld，docker，kube-proxy,kubelet服务，并设置开机启动。要按以下顺序etcd—->flannel—–>docker启动,否则会导致pod里边的ip会和其他node节点的pod不在一个网段，通信就有问题。