Kubernetes是谷歌开源的容器集群编排平台，是一个完备的分布式系统支撑平台，为容器化应用提供部署运行、资源调度、服务发现和动态伸缩等一系列完整功能，具有强大的故障发现和自我修复机制、服务滚动升级和在线扩容能力，可扩展资源自动调度机制以及多粒度的资源配额管理能力。
Kubernetes目前以77%的市场份额独占容器编排平台市场鳌头。目前所有的主要云服务提供商（亚马逊、微软、Google、IBM等）都将其作为部署云原生应用的解决方案。Kubernetes已经在大量企业中落地，并广泛的运用在生产环境中。
作为容器化的主流运行和编排管理平台，Kubernetes的重要性毋庸置疑，以下相关内容只是本人的相关笔记，仅作参考，欢迎业内各路大神指点。
下面是K8S架构简图：
可以看出，K8S架构分Master+Node两部分，其中Master节点作为管理节点，主要提供管理用户相关操作，Node节点作为应用部署节点，实现业务功能，被Master节点管理控制和调度。通过Master和Node节点的各大组件，不难看出，要安装K8S集群，需要分别安装如下组件：
Master节点：
| 组件名称 | 组件说明 |
| etcd | 非关系型数据库，用于存储相关信息 |
| kube-apiserver | 核心通信组件，其他组件通过它实现通信 |
| kube-controller-manager | 集群内部管理中心，通过各种manager实现集群管理 |
| kube-scheduler | 负责相关调度，比如node上pod的调度 |
Node节点：
| 组件名称 | 组件说明 |
| kube-proxy | 负责网络通信，相当与代理，实现请求到pod的转发 |
| kubelet | node节点核心组件，作为Master节点任务的执行者 |
安装环境如下：
| 操作系统 | 节点角色 | 节点IP |
| centOS7.2 X64 | Master | 120.27.15.116 |
| centOS7.2 X64 | node | 39.108.85.46 |
安装过程如下：
step1、安装etcd，这个不属于k8s的东东，直接通过yum install etcd 安装即可
1 [root@alta-sz kubernetes]# yum install etcd 2 Loaded plugins: fastestmirror 3 Loading mirror speeds from cached hostfile 4 Resolving Dependencies 5 --> Running transaction check 6 ---> Package etcd.x86_64 0:3.2.22-1.el7 will be installed 7 --> Finished Dependency Resolution 8 9 Dependencies Resolved 10 11 ======================================================================================================================================================================== 12 Package Arch Version Repository Size 13 ======================================================================================================================================================================== 14 Installing: 15 etcd x86_64 3.2.22-1.el7 extras 9.3 M 16 17 Transaction Summary 18 ======================================================================================================================================================================== 19 Install 1 Package 20 21 Total download size: 9.3 M 22 Installed size: 42 M 23 Is this ok [y/d/N]: y 24 Downloading packages: 25 etcd-3.2.22-1.el7.x86_64.rpm | 9.3 MB 00:00:01 26 Running transaction check 27 Running transaction test 28 Transaction test succeeded 29 Running transaction 30 Installing : etcd-3.2.22-1.el7.x86_64 1/1 31 Verifying : etcd-3.2.22-1.el7.x86_64 1/1 32 33 Installed: 34 etcd.x86_64 0:3.2.22-1.el7 35 36 Complete!
安装完进行配置：
vi /etc/etcd/etcd.conf
1 [root@alta-sz etcd]# vi /etc/etcd/etcd.conf 2 3 #[Member] 4 #ETCD_CORS="" 5 ETCD_DATA_DIR="/var/lib/etcd/default.etcd" 6 #ETCD_WAL_DIR="" 7 #ETCD_LISTEN_PEER_URLS="http://localhost:2380" 8 ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379,http://0.0.0.0:4001" 9 #ETCD_MAX_SNAPSHOTS="5" 10 #ETCD_MAX_WALS="5" 11 ETCD_NAME="master" 12 #ETCD_SNAPSHOT_COUNT="100000" 13 #ETCD_HEARTBEAT_INTERVAL="100" 14 #ETCD_ELECTION_TIMEOUT="1000" 15 #ETCD_QUOTA_BACKEND_BYTES="0" 16 #ETCD_MAX_REQUEST_BYTES="1572864" 17 #ETCD_GRPC_KEEPALIVE_MIN_TIME="5s" 18 #ETCD_GRPC_KEEPALIVE_INTERVAL="2h0m0s" 19 #ETCD_GRPC_KEEPALIVE_TIMEOUT="20s" 20 21 # 22 #[Clustering] 23 #ETCD_INITIAL_ADVERTISE_PEER_URLS="http://localhost:2380" 24 ETCD_ADVERTISE_CLIENT_URLS="http://120.27.15.116:2379,http://120.27.15.116:4001" 25 #ETCD_DISCOVERY="" 26 #ETCD_DISCOVERY_FALLBACK="proxy" 27 #ETCD_DISCOVERY_PROXY="" 28 #ETCD_DISCOVERY_SRV="" 29 #ETCD_INITIAL_CLUSTER="default=http://localhost:2380" 30 #ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster" 31 #ETCD_INITIAL_CLUSTER_STATE="new" 32 #ETCD_STRICT_RECONFIG_CHECK="true" 33 #ETCD_ENABLE_V2="true" 34 # 35 #[Proxy] 36 #ETCD_PROXY="off" 37 #ETCD_PROXY_FAILURE_WAIT="5000" 38 #ETCD_PROXY_REFRESH_INTERVAL="30000" 39 #ETCD_PROXY_DIAL_TIMEOUT="1000" 40 #ETCD_PROXY_WRITE_TIMEOUT="5000" 41 #ETCD_PROXY_READ_TIMEOUT="0" 42 # 43 #[Security] 44 #ETCD_CERT_FILE="" 45 #ETCD_KEY_FILE="" 46 #ETCD_CLIENT_CERT_AUTH="false" 47 #ETCD_TRUSTED_CA_FILE="" 48 #ETCD_AUTO_TLS="false" 49 #ETCD_PEER_CERT_FILE="" 50 #ETCD_PEER_KEY_FILE="" 51 #ETCD_PEER_CLIENT_CERT_AUTH="false" 52 #ETCD_PEER_TRUSTED_CA_FILE="" 53 #ETCD_PEER_AUTO_TLS="false" 54 # 55 #[Logging] 56 #ETCD_DEBUG="false" 57 #ETCD_LOG_PACKAGE_LEVELS="" 58 #ETCD_LOG_OUTPUT="default" 59 # 60 #[Unsafe] 61 #ETCD_FORCE_NEW_CLUSTER="false" 62 # 63 #[Version] 64 #ETCD_VERSION="false" 65 #ETCD_AUTO_COMPACTION_RETENTION="0" 66 # 67 #[Profiling] 68 #ETCD_ENABLE_PPROF="false" 69 #ETCD_METRICS="basic" 70 # 71 #[Auth] 72 #ETCD_AUTH_TOKEN="simple"
启动etcd，然后测试：
systemctl enable etcd
systemctl start etcd
分别存入一个值{test/key1:123}进行测试
etcdctl set test/key1 123
etcd get test/key1
1 [root@alta-sz etcd]# etcdctl set test/key1 123 2 123 3 [root@alta-sz etcd]# etcdctl get test/key1 4 123 5 [root@alta-sz etcd]# 6 [root@alta-sz etcd]# 7 [root@alta-sz etcd]# 8 [root@alta-sz etcd]# etcdctl -C http://localhost:2379 cluster-health 9 member 8e9e05c52164694d is healthy: got healthy result from http://localhost:2379 10 cluster is healthy
以上说明etcd安装成功了！
step2、Master节点安装Kubernetes
执行：yum install kubernetes -y
1 [root@alta-sz k8s]# yum install kubernetes -y 2 Loaded plugins: fastestmirror 3 Loading mirror speeds from cached hostfile 4 Resolving Dependencies 5 --> Running transaction check 6 ---> Package kubernetes.x86_64 0:1.5.2-0.7.git269f928.el7 will be installed 7 --> Processing Dependency: kubernetes-node = 1.5.2-0.7.git269f928.el7 for package: kubernetes-1.5.2-0.7.git269f928.el7.x86_64 8 --> Processing Dependency: kubernetes-master = 1.5.2-0.7.git269f928.el7 for package: kubernetes-1.5.2-0.7.git269f928.el7.x86_64 9 --> Running transaction check 10 ---> Package kubernetes-master.x86_64 0:1.5.2-0.7.git269f928.el7 will be installed 11 --> Processing Dependency: kubernetes-client = 1.5.2-0.7.git269f928.el7 for package: kubernetes-master-1.5.2-0.7.git269f928.el7.x86_64 12 ---> Package kubernetes-node.x86_64 0:1.5.2-0.7.git269f928.el7 will be installed 13 --> Processing Dependency: socat for package: kubernetes-node-1.5.2-0.7.git269f928.el7.x86_64 14 --> Processing Dependency: conntrack-tools for package: kubernetes-node-1.5.2-0.7.git269f928.el7.x86_64 15 --> Running transaction check 16 ---> Package conntrack-tools.x86_64 0:1.4.4-3.el7_3 will be installed 17 --> Processing Dependency: libnetfilter_cttimeout.so.1(LIBNETFILTER_CTTIMEOUT_1.1)(64bit) for package: conntrack-tools-1.4.4-3.el7_3.x86_64 18 --> Processing Dependency: libnetfilter_cttimeout.so.1(LIBNETFILTER_CTTIMEOUT_1.0)(64bit) for package: conntrack-tools-1.4.4-3.el7_3.x86_64 19 --> Processing Dependency: libnetfilter_cthelper.so.0(LIBNETFILTER_CTHELPER_1.0)(64bit) for package: conntrack-tools-1.4.4-3.el7_3.x86_64 20 --> Processing Dependency: libnetfilter_queue.so.1()(64bit) for package: conntrack-tools-1.4.4-3.el7_3.x86_64 21 --> Processing Dependency: libnetfilter_cttimeout.so.1()(64bit) for package: conntrack-tools-1.4.4-3.el7_3.x86_64 22 --> Processing Dependency: libnetfilter_cthelper.so.0()(64bit) for package: conntrack-tools-1.4.4-3.el7_3.x86_64 23 ---> Package kubernetes-client.x86_64 0:1.5.2-0.7.git269f928.el7 will be installed 24 ---> Package socat.x86_64 0:1.7.3.2-2.el7 will be installed 25 --> Running transaction check 26 ---> Package libnetfilter_cthelper.x86_64 0:1.0.0-9.el7 will be installed 27 ---> Package libnetfilter_cttimeout.x86_64 0:1.0.0-6.el7 will be installed 28 ---> Package libnetfilter_queue.x86_64 0:1.0.2-2.el7_2 will be installed 29 --> Finished Dependency Resolution 30 31 Dependencies Resolved 32 33 ======================================================================================================================================================================== 34 Package Arch Version Repository Size 35 ======================================================================================================================================================================== 36 Installing: 37 kubernetes x86_64 1.5.2-0.7.git269f928.el7 extras 36 k 38 Installing for dependencies: 39 conntrack-tools x86_64 1.4.4-3.el7_3 base 186 k 40 kubernetes-client x86_64 1.5.2-0.7.git269f928.el7 extras 14 M 41 kubernetes-master x86_64 1.5.2-0.7.git269f928.el7 extras 25 M 42 kubernetes-node x86_64 1.5.2-0.7.git269f928.el7 extras 14 M 43 libnetfilter_cthelper x86_64 1.0.0-9.el7 base 18 k 44 libnetfilter_cttimeout x86_64 1.0.0-6.el7 base 18 k 45 libnetfilter_queue x86_64 1.0.2-2.el7_2 base 23 k 46 socat x86_64 1.7.3.2-2.el7 base 290 k 47 48 Transaction Summary 49 ======================================================================================================================================================================== 50 Install 1 Package (+8 Dependent packages) 51 52 Total download size: 54 M 53 Installed size: 304 M 54 Downloading packages: 55 (1/9): kubernetes-1.5.2-0.7.git269f928.el7.x86_64.rpm | 36 kB 00:00:01 56 (2/9): conntrack-tools-1.4.4-3.el7_3.x86_64.rpm | 186 kB 00:00:01 57 (3/9): kubernetes-client-1.5.2-0.7.git269f928.el7.x86_64.rpm | 14 MB 00:00:02 58 (4/9): libnetfilter_cttimeout-1.0.0-6.el7.x86_64.rpm | 18 kB 00:00:00 59 (5/9): libnetfilter_cthelper-1.0.0-9.el7.x86_64.rpm | 18 kB 00:00:00 60 (6/9): libnetfilter_queue-1.0.2-2.el7_2.x86_64.rpm | 23 kB 00:00:00 61 (7/9): kubernetes-node-1.5.2-0.7.git269f928.el7.x86_64.rpm | 14 MB 00:00:00 62 (8/9): socat-1.7.3.2-2.el7.x86_64.rpm | 290 kB 00:00:00 63 (9/9): kubernetes-master-1.5.2-0.7.git269f928.el7.x86_64.rpm | 25 MB 00:00:01 64 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ 65 Total 17 MB/s | 54 MB 00:00:03 66 Running transaction check 67 Running transaction test 68 Transaction test succeeded 69 Running transaction 70 Installing : kubernetes-client-1.5.2-0.7.git269f928.el7.x86_64 1/9 71 Installing : kubernetes-master-1.5.2-0.7.git269f928.el7.x86_64 2/9 72 Installing : socat-1.7.3.2-2.el7.x86_64 3/9 73 Installing : libnetfilter_cthelper-1.0.0-9.el7.x86_64 4/9 74 Installing : libnetfilter_queue-1.0.2-2.el7_2.x86_64 5/9 75 Installing : libnetfilter_cttimeout-1.0.0-6.el7.x86_64 6/9 76 Installing : conntrack-tools-1.4.4-3.el7_3.x86_64 7/9 77 Installing : kubernetes-node-1.5.2-0.7.git269f928.el7.x86_64 8/9 78 Installing : kubernetes-1.5.2-0.7.git269f928.el7.x86_64 9/9 79 Verifying : libnetfilter_cttimeout-1.0.0-6.el7.x86_64 1/9 80 Verifying : libnetfilter_queue-1.0.2-2.el7_2.x86_64 2/9 81 Verifying : kubernetes-node-1.5.2-0.7.git269f928.el7.x86_64 3/9 82 Verifying : kubernetes-client-1.5.2-0.7.git269f928.el7.x86_64 4/9 83 Verifying : kubernetes-master-1.5.2-0.7.git269f928.el7.x86_64 5/9 84 Verifying : libnetfilter_cthelper-1.0.0-9.el7.x86_64 6/9 85 Verifying : conntrack-tools-1.4.4-3.el7_3.x86_64 7/9 86 Verifying : socat-1.7.3.2-2.el7.x86_64 8/9 87 Verifying : kubernetes-1.5.2-0.7.git269f928.el7.x86_64 9/9 88 89 Installed: 90 kubernetes.x86_64 0:1.5.2-0.7.git269f928.el7 91 92 Dependency Installed: 93 conntrack-tools.x86_64 0:1.4.4-3.el7_3 kubernetes-client.x86_64 0:1.5.2-0.7.git269f928.el7 kubernetes-master.x86_64 0:1.5.2-0.7.git269f928.el7 94 kubernetes-node.x86_64 0:1.5.2-0.7.git269f928.el7 libnetfilter_cthelper.x86_64 0:1.0.0-9.el7 libnetfilter_cttimeout.x86_64 0:1.0.0-6.el7 95 libnetfilter_queue.x86_64 0:1.0.2-2.el7_2 socat.x86_64 0:1.7.3.2-2.el7 96 97 Complete!
安装完成可以分别查看如下目录文件：
step3、配置Master节点，Master节点需要配置config、apiserver、controller-manager、schduler
1、config配置:vi /etc/kubernetes/config 主要配置其中的参数KUBE_MASTER
2、apiserver配置：vi /etc/kubernetes/apiserver
参数说明：
KUBE_API_ADDRESS:ApiServer监听IP地址，配置为0.0.0.0，监听所有
KUBE_API_PORT:ApIServer监听端口
KUBE_ETCD_SERVERS:ETCD存储服务器IP+PORT
3、controller-manager配置:保持默认即可
4、schduler配置:保持默认即可
step4、启动Master节点
启动apiserver:
systemctl enable kube-apiserver.service
systemctl start kube-apiserver.service
启动controller-manager:
systemctl enable kube-controller-manager.service
systemctl start kube-controller-manager.service
启动scheduler:
systemctl enable kube-scheduler.service
systemctl start kube-scheduler.service
至此，Master节点就安装完成了，下面继续Node节点的安装。
step5、安装Node节点
yum install kubernetes -y 安装和Master的步骤相同
step6、配置Node节点、Node节点需要配置config、kubelet、proxy
1、配置config:vi /etc/kubernetes/config
2、配置kubelet:vi /etc/kubernetes/kublet
3、配置proxy:保持默认即可
step7、启动Node节点
启动kubelet:
systemctl enable kubelet.service
systemctl startkubelet.service
启动proxy:
systemctl enable kube-proxy.service
systemctl startkube-proxy.service
step8、测试验证
到Master节点执行：kubectl get nodes 如下，node节点成功加入到Master。
一个简单的Kubernetes集群就搭建起来了。