我是先对docker初步到进阶的了解学习,常用的命令,基本的容器构建和docker原理概念学习完之后,步入k8s。即使这样,刚看k8s官方文档时,其设计理念、组件构成以及生态需要了解掌握的知识不在少数。为此,花了几天时间在官方文档&个人博客上做了上述方面初步了解,较为直观的便可分为两方面:
master:
- API server
- Controller Manager
- Scheduler
- Etcd
node:
- kublet
- kube-proxy
- pod
Kubernetes集群组件:
- etcd 一个高可用的K/V键值对存储和服务发现系统
- flannel 实现夸主机的容器网络的通信
- kube-apiserver 提供kubernetes集群的API调用
- kube-controller-manager 确保集群服务
- kube-scheduler 调度容器,分配到Node
- kubelet 在Node节点上按照配置文件中定义的容器规格启动容器
- kube-proxy 提供网络代理服务
这些是在安装过程中直接接触的组件,了解其用途和原理会更胸有成竹吧。
若没有docker基础,应优先学习docker,在构建k8s时更易切解决碰到的问题。
搭建过程
官网给出的搭建流程不是很满意,会出问题,环境不同异常不同,排查起来需要用时间填坑;此外也有大量开发者给出的个人经验很有借鉴意义但也是有漏洞,或不详尽,或漏洞百出,需要读多篇这样的文章,相互比较找出漏洞形成完整的搭建思路才方便一部搭建到位,说简单也简单,复杂也是。
- 环境:centos 7
- ecs-ali2 master
- ecs-ali3 node
因另外一台服务器负载较高,所以就搭建2个节点的集群,还是有别于但节点服务器的。3+节点的单间过程和此文相同,复制node搭建过程便可。
注意:如果你的服务器已经安装过docker,依据我的建议是应该卸载干净,不然会因kubernetes-node和docker产生冲突,导致node启动不了,找不到服务。
master环境搭建
关闭防火墙
我因使用的是iptables,在以前安装centos7时就变更了防火墙软件,不然建议先禁用centos7自带的Firewall
systemctl stop firewalld master node环境各执行一遍
systemctl disable firewalld
确保epel源
yum -y install epel-release master node环境各执行一遍
master安装etcd kubernetes-master
yum -y install etcd kubernetes-master
编辑/etc/etcd/etcd.conf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://127.0.0.1:2379"
# 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"
# Add your own!
KUBE_API_ARGS=""
[root@ecs-ali2 kubernetes]# cat /etc/etcd/etcd.conf
#[Member]
#ETCD_CORS=""
ETCD_DATA_DIR="/var/lib/etcd/default.etcd" //※在此
#ETCD_WAL_DIR=""
#ETCD_LISTEN_PEER_URLS="http://localhost:2380"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379" //※在此
#ETCD_MAX_SNAPSHOTS="5"
#ETCD_MAX_WALS="5"
ETCD_NAME="default" //※在此
#ETCD_SNAPSHOT_COUNT="100000"
#ETCD_HEARTBEAT_INTERVAL="100"
#ETCD_ELECTION_TIMEOUT="1000"
#ETCD_QUOTA_BACKEND_BYTES="0"
#
#[Clustering]
#ETCD_INITIAL_ADVERTISE_PEER_URLS="http://localhost:2380"
ETCD_ADVERTISE_CLIENT_URLS="http://ecs-ali2:2379" //※在此
#ETCD_DISCOVERY=""
#ETCD_DISCOVERY_FALLBACK="proxy"
#ETCD_DISCOVERY_PROXY=""
#ETCD_DISCOVERY_SRV=""
#ETCD_INITIAL_CLUSTER="default=http://localhost:2380"
#ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
#ETCD_INITIAL_CLUSTER_STATE="new"
#ETCD_STRICT_RECONFIG_CHECK="true"
#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"
#ETCD_LOG_PACKAGE_LEVELS=""
#ETCD_LOG_OUTPUT="default"
#
#[Unsafe]
#ETCD_FORCE_NEW_CLUSTER="false"
#
#[Version]
#ETCD_VERSION="false"
#ETCD_AUTO_COMPACTION_RETENTION="0"
#
#[Profiling]
#ETCD_ENABLE_PPROF="false"
#ETCD_METRICS="basic"
#
#[Auth]
#ETCD_AUTH_TOKEN="simple"
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://127.0.0.1:2379"
# 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"
# Add your own!
KUBE_API_ARGS=""
启动etcd、kube-apiserver、kube-controller-manager、kube-scheduler等服务,并设置开机启动。
建议写一个脚本 kubernetes-master-start.sh,每次执行脚本就好
#!/usr/bin/env bash
for SERVICES in etcd kube-apiserver kube-controller-manager kube-scheduler; do
systemctl restart $SERVICES
systemctl enable $SERVICES
systemctl status $SERVICES
done
保存退出后执行下面命令增加可执行权限:
chmod +x kubernetes-master-start.sh
etcd、kube-apiserver、kube-controller-manager、kube-scheduler等服务停止脚本
建议写一个脚本 kubernetes-master-end.sh,每次执行脚本就好
#!/usr/bin/env bash
for SERVICES in etcd kube-apiserver kube-controller-manager kube-scheduler; do
systemctl stop $SERVICES
systemctl status $SERVICES
done
保存退出后执行下面命令增加可执行权限:
chmod +x kubernetes-master-start.sh
执行后,service的status将会是active (running),否则将是空的,或者执行:
netstat -ntlp
若有:
tcp 0 0 172.19.17.95:2380 0.0.0.0:* LISTEN 25633/etcd
tcp6 0 0 :::10251 :::* LISTEN 大专栏 Build Kubernetes[k8s] clusters="mi">25728/kube-schedule
tcp6 0 0 :::6443 :::* LISTEN 25667/kube-apiserve
tcp6 0 0 :::2379 :::* LISTEN 25633/etcd
tcp6 0 0 :::10252 :::* LISTEN 25696/kube-controll
tcp6 0 0 :::8080 :::* LISTEN 25667/kube-apiserve
则恭喜你成了
在etcd中定义flannel网络
etcdctl mk /atomic.io/network/config '{"Network":"172.17.0.0/16"}
然后你可以访问master节点8080端口,将会返会json格式的节点环境数据!
node环境搭建
执行下面命令前,确认是否已经安装docker,若是则卸载,不然出问题,即使卸载后,kubernetes-node也会再次自动装上docker。
安装flannel和kubernetes-node
yum -y install flannel kubernetes-node
编辑/etc/etcd/etcd.conf文件
# Flanneld configuration options
# etcd url location. Point this to the server where etcd runs
FLANNEL_ETCD_ENDPOINTS="http://ecs-ali2:2379"
# 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=""
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://ecs-ali2:8080"
在所有Node节点上启动kube-proxy,kubelet,docker,flanneld等服务,并设置开机启动
建议写一个脚本 kubernetes-node-start.sh,每次执行脚本就好
#!/usr/bin/env bash
for SERVICES in kube-proxy kubelet docker; do
systemctl restart $SERVICES
systemctl enable $SERVICES
systemctl status $SERVICES
done
保存退出后执行下面命令增加可执行权限:
chmod +x kubernetes-master-start.sh
结束kube-proxy,kubelet,docker,flanneld等服务
建议写一个脚本 kubernetes-node-start.sh,每次执行脚本就好
#!/usr/bin/env bash
for SERVICES in kube-proxy kubelet docker; do
systemctl stop $SERVICES
systemctl status $SERVICES
done
保存退出后执行下面命令增加可执行权限:
chmod +x kubernetes-master-start.sh
执行后,service的status将会是active (running),否则将是空的,或者执行:
netstat -ntlp
若有:
tcp 0 0 127.0.0.1:10248 0.0.0.0:* LISTEN 14484/kubelet
tcp 0 0 127.0.0.1:10249 0.0.0.0:* LISTEN 14080/kube-proxy
tcp6 0 0 :::10250 :::* LISTEN 14484/kubelet
tcp6 0 0 :::10255 :::* LISTEN 14484/kubelet
tcp6 0 0 :::4194 :::* LISTEN 14484/kubelet
则恭喜你成了
集群环境验证
在master上执行如下命令
kubectl get node
我的是:
[root@ecs-ali2 yum.repos.d]# kubectl get node
NAME STATUS AGE
ecs-ali3 Ready 1h
状态为Ready,则说明集群搭建成功
官方文档采坑点
https://www.kubernetes.org.cn/doc-16,若是参考这个,以下是一些碰到的问题:
在添加添加virt7-testing源,其使用下面信息添加源:
[virt7-testing]
name=virt7-testing
baseurl=http://cbs.centos.org/repos/virt7-testing/x86_64/os/
gpgcheck=0
然后安转过程提示:
failure: repodata/repomd.xml from virt7-testing: [Errno 256] No more mirrors to try.
http://cbs.centos.org/repos/virt7-testing/x86_64/os/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found
解决办法:
替换baseurl
baseurl=http://cbs.centos.org/repos/virt7-docker-common-candidate/x86_64/os/
反正照着官方汉化文档我没有成功,应该不是我智商着急的原因!
参考文档
原文地址:https://www.cnblogs.com/sanxiandoupi/p/11712786.html