K8S学习笔记之二进制的方式创建一个Kubernetes集群

0x00 单节点搭建和简述

minikube

Minikube是一个工具，可以在本地快速运行一个单点的Kubernetes，尝试Kubernetes或日常开发的用户使用。不能用于生产环境。

官方地址：https://kubernetes.io/docs/setup/minikube/

kubeadm

Kubeadm也是一个工具，提供kubeadm init和kubeadm join，用于快速部署Kubernetes集群。

官方地址：https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm/

二进制包

从官方下载发行版的二进制包，手动部署每个组件，组成Kubernetes集群，https://kubernetes.io/docs/home/。

官方也提供了一个互动测试环境供大家玩耍：https://kubernetes.io/cn/docs/tutorials/kubernetes-basics/cluster-interactive/

生产环境中部署Kubernetes集群，只有Kubeadm和二进制包可选，Kubeadm降低部署门槛，但屏蔽了很多细节，遇到问题很难排查。我们这里使用二进制包部署Kubernetes集群，我也是推荐大家使用这种方式，虽然手动部署麻烦点，但学习很多工作原理，更有利于后期维护。

在部署之前，有个职场情况给大家分享下，咱们是为公司打工，拿着老板的工资，在其位谋其职，一定要突出自己的工作，不要做幕后工作者，也就是说做的任何事都尽量量化，让领导知道。

一个正确的工作方式应该是这样的：

# 1.梳理现状，发现问题；
# 2.分析问题大致解决方案；
# 3.如果有多种方案，总结利弊，向上级汇报；
# 4.如果需要部门协作，开会讨论，确定可行性方案，立项；
# 5.会议立项后，制定具体执行方案；
# 6.评审通过后，实施；
# 7.最后项目报告。

0x01 Kubernetes集群部署架构规划

软件环境

硬件环境

Kubernetes 架构图

Kubernetes工作流程

0x02 部署Etcd集群

在Master节点操作，使用cfssl来生成自签证书，先下载cfssl工具，下面操作请新建一个文件夹，在文件夹内操作。

wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo

2.1 生成Etcd证书

在Master节点操作，创建以下三个文件

# cat ca-config.json
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "www": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}

# cat ca-csr.json
{
    "CN": "etcd CA",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing"
        }
    ]
}

# cat server-csr.json
{
    "CN": "etcd",
    "hosts": [
    "192.168.26.135",
    "192.168.26.136",
    "192.168.26.137"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing"
        }
    ]
}

生成证书

cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server

# ls *pem
ca-key.pem  ca.pem  server-key.pem  server.pem

2.2 安装Etcd

以下操作需要在三个节点上操作，二进制包下载地址：https://github.com/coreos/etcd/releases/tag/v3.2.12

# 以下部署步骤在规划的三个etcd节点操作一样，唯一不同的是etcd配置文件中的服务器IP要写当前主机的IP：

解压二进制包

mkdir /opt/etcd/{bin,cfg,ssl} -p
tar zxvf etcd-v3.2.12-linux-amd64.tar.gz
mv etcd-v3.2.12-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

创建etcd配置文件，注意在不同节点上操作，要替换为各个节点的IP，此处是135节点的示例

# vim /opt/etcd/cfg/etcd
#[Member]
ETCD_NAME="etcd01"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.26.135:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.26.135:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.26.135:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.26.135:2379"
ETCD_INITIAL_CLUSTER="etcd01=https://192.168.26.135:2380,etcd02=https://192.168.26.136:2380,etcd03=https://192.168.26.137:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

# ETCD_NAME 节点名称
# ETCD_DATA_DIR 数据目录
# ETCD_LISTEN_PEER_URLS 集群通信监听地址
# ETCD_LISTEN_CLIENT_URLS 客户端访问监听地址
# ETCD_INITIAL_ADVERTISE_PEER_URLS 集群通告地址
# ETCD_ADVERTISE_CLIENT_URLS 客户端通告地址
# ETCD_INITIAL_CLUSTER 集群节点地址
# ETCD_INITIAL_CLUSTER_TOKEN 集群Token
# ETCD_INITIAL_CLUSTER_STATE 加入集群的当前状态，new是新集群，existing表示加入已有集群

创建systemd管理etcd，在三个节点上都要操作

# vim /usr/lib/systemd/system/etcd.service
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd
ExecStart=/opt/etcd/bin/etcd \
--name=${ETCD_NAME} \
--data-dir=${ETCD_DATA_DIR} \
--listen-peer-urls=${ETCD_LISTEN_PEER_URLS} \
--listen-client-urls=${ETCD_LISTEN_CLIENT_URLS},http://127.0.0.1:2379 \
--advertise-client-urls=${ETCD_ADVERTISE_CLIENT_URLS} \
--initial-advertise-peer-urls=${ETCD_INITIAL_ADVERTISE_PEER_URLS} \
--initial-cluster=${ETCD_INITIAL_CLUSTER} \
--initial-cluster-token=${ETCD_INITIAL_CLUSTER_TOKEN} \
--initial-cluster-state=new \
--cert-file=/opt/etcd/ssl/server.pem \
--key-file=/opt/etcd/ssl/server-key.pem \
--peer-cert-file=/opt/etcd/ssl/server.pem \
--peer-key-file=/opt/etcd/ssl/server-key.pem \
--trusted-ca-file=/opt/etcd/ssl/ca.pem \
--peer-trusted-ca-file=/opt/etcd/ssl/ca.pem
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

把新建文件夹中的证书拷贝到各个节点如下的位置，每个节点的这个文件夹下都要有这些.pem证书，可以使用scp跨主机传输

cp ca*pem server*pem /opt/etcd/ssl

启动并设置开启启动

systemctl start etcd
systemctl enable etcd

都部署完成后，检查etcd集群状态（注意正确填写.pem证书的路径）

# /opt/etcd/bin/etcdctl \
--ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem \
--endpoints="https://192.168.26.135:2379,https://192.168.26.136:2379,https://192.168.26.137:2379" \
cluster-health
member 18218cfabd4e0dea is healthy: got healthy result from https://192.168.26.135:2379
member 541c1c40994c939b is healthy: got healthy result from https://192.168.26.136:2379
member a342ea2798d20705 is healthy: got healthy result from https://192.168.26.137:2379
cluster is healthy

如果输出上面信息，就说明集群部署成功。如果有问题第一步先看日志：/var/log/message 或 journalctl -u etcd

0x03 在Node节点安装Docker

在两台node节点安装

yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo
yum install docker-ce -y
curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s http://bc437cce.m.daocloud.io
systemctl start docker
systemctl enable docker

0x04 部署Flannel网络

Flannel工作原理

Falnnel要用etcd存储自身一个子网信息，所以要保证能成功连接Etcd，写入预定义子网段，在任一个节点执行如下命令即可

# /opt/etcd/bin/etcdctl \
--ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem \
--endpoints="https://192.168.26.135:2379,https://192.168.26.136:2379,https://192.168.26.137:2379" \
set /coreos.com/network/config  '{ "Network": "172.17.0.0/16", "Backend": {"Type": "vxlan"}}'

以下部署步骤在规划的每个node节点都操作

下载二进制包

wget https://github.com/coreos/flannel/releases/download/v0.10.0/flannel-v0.10.0-linux-amd64.tar.gz
tar zxvf flannel-v0.10.0-linux-amd64.tar.gz
mv flanneld mk-docker-opts.sh /opt/kubernetes/bin

配置Flannel

# vim /opt/kubernetes/cfg/flanneld
FLANNEL_OPTIONS="--etcd-endpoints=https://192.168.26.135:2379,https://192.168.26.136:2379,https://192.168.26.137:2379 -etcd-cafile=/opt/etcd/ssl/ca.pem -etcd-certfile=/opt/etcd/ssl/server.pem -etcd-keyfile=/opt/etcd/ssl/server-key.pem"

创建systemd管理Flannel

# vim /usr/lib/systemd/system/flanneld.service

[Unit]
Description=Flanneld overlay address etcd agent
After=network-online.target network.target
Before=docker.service

[Service]
Type=notify
EnvironmentFile=/opt/kubernetes/cfg/flanneld
ExecStart=/opt/kubernetes/bin/flanneld --ip-masq $FLANNEL_OPTIONS
ExecStartPost=/opt/kubernetes/bin/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/subnet.env
Restart=on-failure

[Install]
WantedBy=multi-user.target

配置Docker启动指定子网段

# vim /usr/lib/systemd/system/docker.service 

[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target

[Service]
Type=notify
EnvironmentFile=/run/flannel/subnet.env
ExecStart=/usr/bin/dockerd $DOCKER_NETWORK_OPTIONS
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TimeoutStartSec=0
Delegate=yes
KillMode=process
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s

[Install]
WantedBy=multi-user.target

重启flannel和docker

# systemctl daemon-reload
# systemctl start flanneld
# systemctl enable flanneld
# systemctl restart docker

检查是否生效

# ps -ef |grep docker
root     20941     1  1 Jun28 ?        09:15:34 /usr/bin/dockerd --bip=172.17.34.1/24 --ip-masq=false --mtu=1450
# ip addr
3607: flannel.1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UNKNOWN
    link/ether 8a:2e:3d:09:dd:82 brd ff:ff:ff:ff:ff:ff
    inet 172.17.34.0/32 scope global flannel.1
       valid_lft forever preferred_lft forever
3608: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UP
    link/ether 02:42:31:8f:d3:02 brd ff:ff:ff:ff:ff:ff
    inet 172.17.34.1/24 brd 172.17.34.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:31ff:fe8f:d302/64 scope link
       valid_lft forever preferred_lft forever

确保docker0与flannel.1在同一网段。
测试不同节点互通，在当前节点访问另一个Node节点docker0
IP：

# ping 172.17.58.1
PING 172.17.58.1 (172.17.58.1) 56(84) bytes of data.
64 bytes from 172.17.58.1: icmp_seq=1 ttl=64 time=0.263 ms
64 bytes from 172.17.58.1: icmp_seq=2 ttl=64 time=0.204 ms

如果能通说明Flannel部署成功。如果不通检查下日志：journalctl -u flannel

0x05 在Master节点部署组件

在部署Kubernetes之前一定要确保etcd、flannel、docker是正常工作的，否则先解决问题再继续。

5.1 生成证书

在Master的一个新建文件夹内进行如下操作.

创建CA证书

# vim ca-config.json
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}

# vim ca-csr.json
{
    "CN": "kubernetes",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}

# cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

生成apiserver证书

# vim server-csr.json
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "192.168.26.135",
      "192.168.26.136",
      "192.168.26.137",
      "kubernetes",
      "kubernetes.default",
      "kubernetes.default.svc",
      "kubernetes.default.svc.cluster",
      "kubernetes.default.svc.cluster.local"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare server

生成kube-proxy证书

# vim kube-proxy-csr.json
{
  "CN": "system:kube-proxy",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing",
      "ST": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}

# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy

最终生成以下证书文件

# ls *pem
ca-key.pem  ca.pem  kube-proxy-key.pem  kube-proxy.pem  server-key.pem  server.pem

5.2 部署apiserver组件

下载二进制包：https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.11.md
下载这个包（kubernetes-server-linux-amd64.tar.gz）就够了，包含了所需的所有组件。

# mkdir /opt/kubernetes/{bin,cfg,ssl} -p
# tar zxvf kubernetes-server-linux-amd64.tar.gz
# cd kubernetes/server/bin
# cp kube-apiserver kube-scheduler kube-controller-manager kubectl /opt/kubernetes/bin

新建token文件

# vim /opt/kubernetes/cfg/token.csv
674c457d4dcf2eefe4920d7dbb6b0ddc,kubelet-bootstrap,10001,"system:kubelet-bootstrap"

# $0：随机字符串，自己可生成
# $1：用户名
# $2：UID
# $3：用户组

创建apiserver配置文件

# vim /opt/kubernetes/cfg/kube-apiserver
KUBE_APISERVER_OPTS="--logtostderr=true \
--v=4 \
--etcd-servers=https://192.168.26.135:2379,https://192.168.26.136:2379,https://192.168.26.137:2379 \
--bind-address=192.168.26.135 \
--secure-port=6443 \
--advertise-address=192.168.26.135\
--allow-privileged=true \
--service-cluster-ip-range=10.0.0.0/24 \
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \
--authorization-mode=RBAC,Node \
--enable-bootstrap-token-auth \
--token-auth-file=/opt/kubernetes/cfg/token.csv \
--service-node-port-range=30000-50000 \
--tls-cert-file=/opt/kubernetes/ssl/server.pem  \
--tls-private-key-file=/opt/kubernetes/ssl/server-key.pem \
--client-ca-file=/opt/kubernetes/ssl/ca.pem \
--service-account-key-file=/opt/kubernetes/ssl/ca-key.pem \
--etcd-cafile=/opt/etcd/ssl/ca.pem \
--etcd-certfile=/opt/etcd/ssl/server.pem \
--etcd-keyfile=/opt/etcd/ssl/server-key.pem"

注意填写证书的路径，并且确保etcd是正常运行。

# --logtostderr 启用日志
# ---v 日志等级
# --etcd-servers etcd集群地址
# --bind-address 监听地址
# --secure-port https安全端口
# --advertise-address 集群通告地址
# --allow-privileged 启用授权
# --service-cluster-ip-range Service虚拟IP地址段
# --enable-admission-plugins 准入控制模块
# --authorization-mode 认证授权，启用RBAC授权和节点自管理
# --enable-bootstrap-token-auth 启用TLS bootstrap功能，后面会讲到
# --token-auth-file token文件
# --service-node-port-range Service Node类型默认分配端口范围

创建systemd管理apiserver

# vim /usr/lib/systemd/system/kube-apiserver.service
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-apiserver
ExecStart=/opt/kubernetes/bin/kube-apiserver $KUBE_APISERVER_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target

# systemctl daemon-reload
# systemctl enable kube-apiserver
# systemctl restart kube-apiserver

5.3 部署schduler组件

创建schduler配置文件

# vim /opt/kubernetes/cfg/kube-scheduler 

KUBE_SCHEDULER_OPTS="--logtostderr=true \
--v=4 \
--master=127.0.0.1:8080 \
--leader-elect"

# --master 连接本地apiserver
# --leader-elect 当该组件启动多个时，自动选举（HA）

systemd管理schduler组件

# vim /usr/lib/systemd/system/kube-scheduler.service
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-scheduler
ExecStart=/opt/kubernetes/bin/kube-scheduler $KUBE_SCHEDULER_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target

# systemctl daemon-reload
# systemctl enable kube-scheduler
# systemctl restart kube-scheduler

5.4 部署controller-manager组件

创建controller-manager配置文件

# vim /opt/kubernetes/cfg/kube-controller-manager
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=true \
--v=4 \
--master=127.0.0.1:8080 \
--leader-elect=true \
--address=127.0.0.1 \
--service-cluster-ip-range=10.0.0.0/24 \
--cluster-name=kubernetes \
--cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem \
--cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem  \
--root-ca-file=/opt/kubernetes/ssl/ca.pem \
--service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem"

systemd管理controller-manager组件

# vim /usr/lib/systemd/system/kube-controller-manager.service
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-controller-manager
ExecStart=/opt/kubernetes/bin/kube-controller-manager $KUBE_CONTROLLER_MANAGER_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target

# systemctl daemon-reload
# systemctl enable kube-controller-manager
# systemctl restart kube-controller-manager

所有组件都已经启动成功，通过kubectl工具查看当前集群组件状态：

# /opt/kubernetes/bin/kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok
etcd-0               Healthy   {"health":"true"}
etcd-2               Healthy   {"health":"true"}
etcd-1               Healthy   {"health":"true"}
controller-manager   Healthy   ok

0x06 在Node节点部署组件

Master apiserver启用TLS认证后，Node节点kubelet组件想要加入集群，必须使用CA签发的有效证书才能与apiserver通信，当Node节点很多时，签署证书是一件很繁琐的事情，因此有了TLS Bootstrapping机制，kubelet会以一个低权限用户自动向apiserver申请证书，kubelet的证书由apiserver动态签署。

认证大致工作流程如图所示：

6.1 将kubelet-bootstrap用户绑定到系统集群角色

在Master‘节点执行此命令

kubectl create clusterrolebinding kubelet-bootstrap \
  --clusterrole=system:node-bootstrapper \
  --user=kubelet-bootstrap

6.2 创建kubeconfig文件

在Master节点执行如下命令，注意.pem文件的路径

在生成kubernetes证书的目录下执行以下命令生成kubeconfig文件：
# 创建kubelet bootstrapping kubeconfig
# 指定apiserver 内网负载均衡地址
KUBE_APISERVER="https://192.168.26.135:6443"
BOOTSTRAP_TOKEN=674c457d4dcf2eefe4920d7dbb6b0ddc

# 设置集群参数
kubectl config set-cluster kubernetes \
  --certificate-authority=./ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=bootstrap.kubeconfig

# 设置客户端认证参数
kubectl config set-credentials kubelet-bootstrap \
  --token=${BOOTSTRAP_TOKEN} \
  --kubeconfig=bootstrap.kubeconfig

# 设置上下文参数
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kubelet-bootstrap \
  --kubeconfig=bootstrap.kubeconfig

# 设置默认上下文
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig

#----------------------

# 创建kube-proxy kubeconfig文件

kubectl config set-cluster kubernetes \
  --certificate-authority=./ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=kube-proxy.kubeconfig

kubectl config set-credentials kube-proxy \
  --client-certificate=./kube-proxy.pem \
  --client-key=./kube-proxy-key.pem \
  --embed-certs=true \
  --kubeconfig=kube-proxy.kubeconfig

kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-proxy \
  --kubeconfig=kube-proxy.kubeconfig

kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
# ls
bootstrap.kubeconfig  kube-proxy.kubeconfig

将这两个文件拷贝到Node节点/opt/kubernetes/cfg目录下，可使用scp命令。

6.3 部署kubelet组件

将前面下载的二进制包server>>bin文件夹下的kubelet和kube-proxy拷贝到各个node节点的/opt/kubernetes/bin目录下，可使用scp命令。

创建kubelet配置文件，如下是在node节点192.168.26.136上的示例

# vim /opt/kubernetes/cfg/kubelet
KUBELET_OPTS="--logtostderr=true \
--v=4 \
--hostname-override=192.168.26.136 \
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \
--config=/opt/kubernetes/cfg/kubelet.config \
--cert-dir=/opt/kubernetes/ssl \
--pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0"

# --hostname-override 在集群中显示的主机名
# --kubeconfig 指定kubeconfig文件位置，会自动生成
# --bootstrap-kubeconfig 指定刚才生成的bootstrap.kubeconfig文件
# --cert-dir 颁发证书存放位置
# --pod-infra-container-image 管理Pod网络的镜像

其中/opt/kubernetes/cfg/kubelet.config配置文件如下：

# vim /opt/kubernetes/cfg/kubelet.config
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 192.168.26.136
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS: ["10.0.0.2"]
clusterDomain: cluster.local.
failSwapOn: false
authentication:
  anonymous:
    enabled: true
  webhook:
    enabled: false

systemd管理kubelet组件

# vim /usr/lib/systemd/system/kubelet.service
[Unit]
Description=Kubernetes Kubelet
After=docker.service
Requires=docker.service

[Service]
EnvironmentFile=/opt/kubernetes/cfg/kubelet
ExecStart=/opt/kubernetes/bin/kubelet $KUBELET_OPTS
Restart=on-failure
KillMode=process

[Install]
WantedBy=multi-user.target

# systemctl daemon-reload
# systemctl enable kubelet
# systemctl restart kubelet

在Master审批Node加入集群：

启动后还没加入到集群中，需要手动允许该节点才可以。
在Master节点查看请求签名的Node：

# kubectl get csr
# kubectl certificate approve XXXXPOD ID
# kubectl get node

systemd管理kube-proxy组件

# vim /usr/lib/systemd/system/kube-proxy.service
[Unit]
Description=Kubernetes Proxy
After=network.target

[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-proxy
ExecStart=/opt/kubernetes/bin/kube-proxy $KUBE_PROXY_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target

# systemctl daemon-reload
# systemctl enable kube-proxy
# systemctl restart kube-proxy

0x07 查看集群状态

# kubectl get node
NAME             STATUS    ROLES     AGE       VERSION
192.168.26.136   Ready     <none>    28d       v1.11.0
192.168.26.137   Ready     <none>    28d       v1.11.0
# kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
controller-manager   Healthy   ok
scheduler            Healthy   ok
etcd-2               Healthy   {"health":"true"}
etcd-1               Healthy   {"health":"true"}
etcd-0               Healthy   {"health":"true"}

0x08 运行一个测试示例

创建一个Nginx Web，判断集群是否正常工作

# kubectl run nginx --image=nginx --replicas=3
# kubectl expose deployment nginx --port=88 --target-port=80 --type=NodePort

查看Pod，Service

# kubectl get pods
NAME                     READY     STATUS    RESTARTS   AGE
nginx-64f497f8fd-fjgt2   1/1       Running   3          28d
nginx-64f497f8fd-gmstq   1/1       Running   3          28d
nginx-64f497f8fd-q6wk9   1/1       Running   3          28d
# kubectl get svc
NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                        AGE
kubernetes   ClusterIP   10.0.0.1     <none>        443/TCP                        28d
nginx        NodePort    10.0.0.175   <none>        88:38696/TCP                   28d

打开浏览器输入：http://192.168.26.136:38696

恭喜你，集群部署成功！

0x09 部署Dashboard(UI)

部署UI有三个文件：

• dashboard-deployment.yaml # 部署Pod，提供Web服务
• dashboard-rbac.yaml # 授权访问apiserver获取信息
• dashboard-service.yaml # 发布服务，提供对外访问

# vim dashboard-deployment.yaml
apiVersion: apps/v1beta2
kind: Deployment
metadata:
  name: kubernetes-dashboard
  namespace: kube-system
  labels:
    k8s-app: kubernetes-dashboard
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
spec:
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
      annotations:
        scheduler.alpha.kubernetes.io/critical-pod: ''
    spec:
      serviceAccountName: kubernetes-dashboard
      containers:
      - name: kubernetes-dashboard
        image: registry.cn-hangzhou.aliyuncs.com/kube_containers/kubernetes-dashboard-amd64:v1.8.1
        resources:
          limits:
            cpu: 100m
            memory: 300Mi
          requests:
            cpu: 100m
            memory: 100Mi
        ports:
        - containerPort: 9090
          protocol: TCP
        livenessProbe:
          httpGet:
            scheme: HTTP
            path: /
            port: 9090
          initialDelaySeconds: 30
          timeoutSeconds: 30
      tolerations:
      - key: "CriticalAddonsOnly"
        operator: "Exists"

# vim dashboard-rbac.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
    addonmanager.kubernetes.io/mode: Reconcile
  name: kubernetes-dashboard
  namespace: kube-system
---

kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: kubernetes-dashboard-minimal
  namespace: kube-system
  labels:
    k8s-app: kubernetes-dashboard
    addonmanager.kubernetes.io/mode: Reconcile
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
  - kind: ServiceAccount
    name: kubernetes-dashboard
    namespace: kube-system

# vim dashboard-service.yaml
apiVersion: v1
kind: Service
metadata:
  name: kubernetes-dashboard
  namespace: kube-system
  labels:
    k8s-app: kubernetes-dashboard
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
spec:
  type: NodePort
  selector:
    k8s-app: kubernetes-dashboard
  ports:
  - port: 80
    targetPort: 9090

创建

# kubectl create -f dashboard-rbac.yaml
# kubectl create -f dashboard-deployment.yaml
# kubectl create -f dashboard-service.yaml

等待数分钟，查看资源状态

# kubectl get all -n kube-system
NAME                                        READY     STATUS    RESTARTS   AGE
pod/kubernetes-dashboard-68ff5fcd99-5rtv7   1/1       Running   1          27d

NAME                           TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
service/kubernetes-dashboard   NodePort    10.0.0.100   <none>        443:30000/TCP   27d

NAME                                   DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/kubernetes-dashboard   1         1         1            1           27d

NAME                                              DESIRED   CURRENT   READY     AGE
replicaset.apps/kubernetes-dashboard-68ff5fcd99   1         1         1         27d

查看访问端口

# kubectl get svc -n kube-system
NAME                   TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
kubernetes-dashboard   NodePort    10.0.0.100   <none>        443:30000/TCP   27d

打开浏览器，输入：http://192.168.26.136:30000

如果你的页面没有图表，这个需要安装heapster，后面会讲到。

0x0A 小结

搭建集群入门比较难，概念比较多，可以先了解一下集群的基本知识和各个组件的作用，熟能生巧，多多练习。

1.最好按照我的配置，先跑通再变通
2.有问题先查日志，再谷歌
3.多思考，多梳理逻辑
4.配置文件较多，有很多字段你可能都不知道干啥，不要着急，随着一步步使用，慢慢就熟悉了

本篇文章来自李振良老师的专栏，如果你觉得不错可以订阅支持原版。