部署一套完整的Kubernetes高可用集群(二进制,最新版v1.18)上
部署一套完整的Kubernetes高可用集群(二进制,最新版v1.18)上

一、前置知识点

1.1 生产环境可部署Kubernetes集群的两种方式

目前生产部署Kubernetes集群主要有两种方式:

  • kubeadm

Kubeadm是一个K8s部署工具,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github下载发行版的二进制包,手动部署每个组件,组成Kubernetes集群。

Kubeadm降低部署门槛,但屏蔽了很多细节,遇到问题很难排查。如果想更容易可控,推荐使用二进制包部署Kubernetes集群,虽然手动部署麻烦点,期间可以学习很多工作原理,也利于后期维护。

1.2 安装要求

在开始之前,部署Kubernetes集群机器需要满足以下几个条件:

  • 一台或多台机器,操作系统 CentOS7.x-86_x64
  • 硬件配置:2GB或更多RAM,2个CPU或更多CPU,硬盘30GB或更多
  • 可以访问外网,需要拉取镜像,如果服务器不能上网,需要提前下载镜像并导入节点
  • 禁止swap分区

1.3 准备环境

软件环境:

软件 版本
操作系统 CentOS7.8_x64 (mini)
Docker 19-ce
Kubernetes 1.18

服务器整体规划:

角色 IP 组件
k8s-master1 192.168.31.71 kube-apiserver,kube-controller-manager,kube-scheduler,etcd
k8s-master2 192.168.31.74 kube-apiserver,kube-controller-manager,kube-scheduler
k8s-node1 192.168.31.72 kubelet,kube-proxy,docker etcd
k8s-node2 192.168.31.73 kubelet,kube-proxy,docker,etcd
Load Balancer(Master) 192.168.31.81 ,192.168.31.88 (VIP) Nginx L4
Load Balancer(Backup) 192.168.31. 82 Nginx L4

须知:考虑到有些朋友电脑配置较低,这么多虚拟机跑不动,所以这一套高可用集群分两部分实施,先部署一套单Master架构(192.168.31.71/72/73),再扩容为多Master架构(上述规划),顺便熟悉下Master扩容流程。

单Master架构图:

部署一套完整的Kubernetes高可用集群(二进制,最新版v1.18)上

单Master服务器规划:

角色 IP 组件
k8s-master 192.168.31.71 kube-apiserver,kube-controller-manager,kube-scheduler,etcd
k8s-node1 192.168.31.72 kubelet,kube-proxy,docker etcd
k8s-node2 192.168.31.73 kubelet,kube-proxy,docker,etcd

1.4 操作系统初始化配置

# 关闭防火墙
systemctl stop firewalld
systemctl disable firewalld

# 关闭selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
setenforce 0  # 临时

# 关闭swap
swapoff -a  # 临时
sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久

# 根据规划设置主机名
hostnamectl set-hostname <hostname>

# 在master添加hosts
cat >> /etc/hosts << EOF
192.168.31.71 k8s-master
192.168.31.72 k8s-node1
192.168.31.73 k8s-node2
EOF

# 将桥接的IPv4流量传递到iptables的链
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system  # 生效

# 时间同步
yum install ntpdate -y
ntpdate time.windows.com

二、部署Etcd集群

Etcd 是一个分布式键值存储系统,Kubernetes使用Etcd进行数据存储,所以先准备一个Etcd数据库,为解决Etcd单点故障,应采用集群方式部署,这里使用3台组建集群,可容忍1台机器故障,当然,你也可以使用5台组建集群,可容忍2台机器故障。

节点名称 IP
etcd-1 192.168.31.71
etcd-2 192.168.31.72
etcd-3 192.168.31.73

注:为了节省机器,这里与K8s节点机器复用。也可以独立于k8s集群之外部署,只要apiserver能连接到就行。

2.1 准备cfssl证书生成工具

cfssl是一个开源的证书管理工具,使用json文件生成证书,相比openssl更方便使用。

找任意一台服务器操作,这里用Master节点。

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

2.2 生成Etcd证书

1. 自签证书颁发机构(CA)

创建工作目录:

mkdir -p ~/TLS/{etcd,k8s}

cd TLS/etcd

自签CA:

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

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

生成证书:

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

ls *pem
ca-key.pem  ca.pem

2. 使用自签CA签发Etcd HTTPS证书

创建证书申请文件:

cat > server-csr.json << EOF
{
    "CN": "etcd",
    "hosts": [
    "192.168.31.71",
    "192.168.31.72",
    "192.168.31.73"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing"
        }
    ]
}
EOF

注:上述文件hosts字段中IP为所有etcd节点的集群内部通信IP,一个都不能少!为了方便后期扩容可以多写几个预留的IP。

生成证书:

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

ls server*pem
server-key.pem  server.pem

2.3 从Github下载二进制文件

下载地址:https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz

2.4 部署Etcd集群

以下在节点1上操作,为简化操作,待会将节点1生成的所有文件拷贝到节点2和节点3.

1. 创建工作目录并解压二进制包

mkdir /opt/etcd/{bin,cfg,ssl} -p
tar zxvf etcd-v3.4.9-linux-amd64.tar.gz
mv etcd-v3.4.9-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

2. 创建etcd配置文件

cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.71:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF
  • ETCD_NAME:节点名称,集群中唯一
  • 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

3. systemd管理etcd

cat > /usr/lib/systemd/system/etcd.service << EOF
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd.conf
ExecStart=/opt/etcd/bin/etcd \
--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 \
--logger=zap
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

4. 拷贝刚才生成的证书

把刚才生成的证书拷贝到配置文件中的路径:

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

5. 启动并设置开机启动

systemctl daemon-reload
systemctl start etcd
systemctl enable etcd

6. 将上面节点1所有生成的文件拷贝到节点2和节点3

scp -r /opt/etcd/ root@192.168.31.72:/opt/
scp /usr/lib/systemd/system/etcd.service root@192.168.31.72:/usr/lib/systemd/system/
scp -r /opt/etcd/ root@192.168.31.73:/opt/
scp /usr/lib/systemd/system/etcd.service root@192.168.31.73:/usr/lib/systemd/system/

然后在节点2和节点3分别修改etcd.conf配置文件中的节点名称和当前服务器IP:

vi /opt/etcd/cfg/etcd.conf
#[Member]
ETCD_NAME="etcd-1"   # 修改此处,节点2改为etcd-2,节点3改为etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.71:2380"   # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379" # 修改此处为当前服务器IP

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379" # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

最后启动etcd并设置开机启动,同上。

7. 查看集群状态

ETCDCTL_API=3 /opt/etcd/bin/etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379" endpoint health

https://192.168.31.71:2379 is healthy: successfully committed proposal: took = 8.154404ms
https://192.168.31.73:2379 is healthy: successfully committed proposal: took = 9.044117ms
https://192.168.31.72:2379 is healthy: successfully committed proposal: took = 10.000825ms

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

三、安装Docker

下载地址:https://download.docker.com/linux/static/stable/x86_64/docker-19.03.9.tgz

以下在所有节点操作。这里采用二进制安装,用yum安装也一样。

3.1 解压二进制包

tar zxvf docker-19.03.9.tgz
mv docker/* /usr/bin

3.2 systemd管理docker

cat > /usr/lib/systemd/system/docker.service << EOF
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target

[Service]
Type=notify
ExecStart=/usr/bin/dockerd
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
EOF

3.3 创建配置文件

mkdir /etc/docker
cat > /etc/docker/daemon.json << EOF
{
  "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF
  • registry-mirrors 阿里云镜像加速器

3.4 启动并设置开机启动

systemctl daemon-reload
systemctl start docker
systemctl enable docker

四、部署Master Node

如果你在学习中遇到问题或者文档有误可联系阿良~ 微信: init1024

4.1 生成kube-apiserver证书

1. 自签证书颁发机构(CA)

cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF
cat > ca-csr.json << EOF
{
    "CN": "kubernetes",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF

生成证书:

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

ls *pem
ca-key.pem  ca.pem

2. 使用自签CA签发kube-apiserver HTTPS证书

创建证书申请文件:

cd TLS/k8s
cat > server-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "192.168.31.71",
      "192.168.31.72",
      "192.168.31.73",
      "192.168.31.74",
      "192.168.31.81",
      "192.168.31.82",
      "192.168.31.88",
      "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"
        }
    ]
}
EOF

注:上述文件hosts字段中IP为所有Master/LB/VIP IP,一个都不能少!为了方便后期扩容可以多写几个预留的IP。

生成证书:

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

ls server*pem
server-key.pem  server.pem

4.2 从Github下载二进制文件

下载地址: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md#v1183

注:打开链接你会发现里面有很多包,下载一个server包就够了,包含了Master和Worker Node二进制文件。

4.3 解压二进制包

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

4.4 部署kube-apiserver

1. 创建配置文件

cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--etcd-servers=https://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379 \\
--bind-address=192.168.31.71 \\
--secure-port=6443 \\
--advertise-address=192.168.31.71 \\
--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=true \\
--token-auth-file=/opt/kubernetes/cfg/token.csv \\
--service-node-port-range=30000-32767 \\
--kubelet-client-certificate=/opt/kubernetes/ssl/server.pem \\
--kubelet-client-key=/opt/kubernetes/ssl/server-key.pem \\
--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 \\
--audit-log-maxage=30 \\
--audit-log-maxbackup=3 \\
--audit-log-maxsize=100 \\
--audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
EOF

注:上面两个\ \ 第一个是转义符,第二个是换行符,使用转义符是为了使用EOF保留换行符。

  • --logtostderr:启用日志
  • ---v:日志等级
  • --log-dir:日志目录
  • --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机制
  • --token-auth-file:bootstrap token文件
  • --service-node-port-range:Service nodeport类型默认分配端口范围
  • --kubelet-client-xxx:apiserver访问kubelet客户端证书
  • --tls-xxx-file:apiserver https证书
  • --etcd-xxxfile:连接Etcd集群证书
  • --audit-log-xxx:审计日志

2. 拷贝刚才生成的证书

把刚才生成的证书拷贝到配置文件中的路径:

cp ~/TLS/k8s/ca*pem ~/TLS/k8s/server*pem /opt/kubernetes/ssl/

3. 启用 TLS Bootstrapping 机制

TLS Bootstraping:Master apiserver启用TLS认证后,Node节点kubelet和kube-proxy要与kube-apiserver进行通信,必须使用CA签发的有效证书才可以,当Node节点很多时,这种客户端证书颁发需要大量工作,同样也会增加集群扩展复杂度。为了简化流程,Kubernetes引入了TLS bootstraping机制来自动颁发客户端证书,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。所以强烈建议在Node上使用这种方式,目前主要用于kubelet,kube-proxy还是由我们统一颁发一个证书。

TLS bootstraping 工作流程:

部署一套完整的Kubernetes高可用集群(二进制,最新版v1.18)上

创建上述配置文件中token文件:

cat > /opt/kubernetes/cfg/token.csv << EOF
c47ffb939f5ca36231d9e3121a252940,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF

格式:token,用户名,UID,用户组

token也可自行生成替换:

head -c 16 /dev/urandom | od -An -t x | tr -d ' '

4. systemd管理apiserver

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

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

[Install]
WantedBy=multi-user.target
EOF

5. 启动并设置开机启动

systemctl daemon-reload
systemctl start kube-apiserver
systemctl enable kube-apiserver

6. 授权kubelet-bootstrap用户允许请求证书

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

4.5 部署kube-controller-manager

1. 创建配置文件

cat > /opt/kubernetes/cfg/kube-controller-manager.conf << EOF
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--leader-elect=true \\
--master=127.0.0.1:8080 \\
--bind-address=127.0.0.1 \\
--allocate-node-cidrs=true \\
--cluster-cidr=10.244.0.0/16 \\
--service-cluster-ip-range=10.0.0.0/24 \\
--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 \\
--experimental-cluster-signing-duration=87600h0m0s"
EOF
  • --master:通过本地非安全本地端口8080连接apiserver。
  • --leader-elect:当该组件启动多个时,自动选举(HA)
  • --cluster-signing-cert-file/--cluster-signing-key-file:自动为kubelet颁发证书的CA,与apiserver保持一致

2. systemd管理controller-manager

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

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

[Install]
WantedBy=multi-user.target
EOF

3. 启动并设置开机启动

systemctl daemon-reload
systemctl start kube-controller-manager
systemctl enable kube-controller-manager

4.6 部署kube-scheduler

1. 创建配置文件

cat > /opt/kubernetes/cfg/kube-scheduler.conf << EOF
KUBE_SCHEDULER_OPTS="--logtostderr=false \
--v=2 \
--log-dir=/opt/kubernetes/logs \
--leader-elect \
--master=127.0.0.1:8080 \
--bind-address=127.0.0.1"
EOF
  • --master:通过本地非安全本地端口8080连接apiserver。
  • --leader-elect:当该组件启动多个时,自动选举(HA)

2. systemd管理scheduler

cat > /usr/lib/systemd/system/kube-scheduler.service << EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes

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

[Install]
WantedBy=multi-user.target
EOF

3. 启动并设置开机启动

systemctl daemon-reload
systemctl start scheduler
systemctl enable scheduler

4. 查看集群状态

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:

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

如上输出说明Master节点组件运行正常。

五、部署Worker Node

如果你在学习中遇到问题或者文档有误可联系阿良~ 微信: init1024

下面还是在Master Node上操作,即同时作为Worker Node

5.1 创建工作目录并拷贝二进制文件

在所有worker node创建工作目录:

mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 

从master节点拷贝:

cd kubernetes/server/bin
cp kubelet kube-proxy /opt/kubernetes/bin   # 本地拷贝

5.2 部署kubelet

1. 创建配置文件

cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-master \\
--network-plugin=cni \\
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \\
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \\
--config=/opt/kubernetes/cfg/kubelet-config.yml \\
--cert-dir=/opt/kubernetes/ssl \\
--pod-infra-container-image=lizhenliang/pause-amd64:3.0"
EOF
  • --hostname-override:显示名称,集群中唯一
  • --network-plugin:启用CNI
  • --kubeconfig:空路径,会自动生成,后面用于连接apiserver
  • --bootstrap-kubeconfig:首次启动向apiserver申请证书
  • --config:配置参数文件
  • --cert-dir:kubelet证书生成目录
  • --pod-infra-container-image:管理Pod网络容器的镜像

2. 配置参数文件

cat > /opt/kubernetes/cfg/kubelet-config.yml << EOF
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 0.0.0.0
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS:
- 10.0.0.2
clusterDomain: cluster.local 
failSwapOn: false
authentication:
  anonymous:
    enabled: false
  webhook:
    cacheTTL: 2m0s
    enabled: true
  x509:
    clientCAFile: /opt/kubernetes/ssl/ca.pem 
authorization:
  mode: Webhook
  webhook:
    cacheAuthorizedTTL: 5m0s
    cacheUnauthorizedTTL: 30s
evictionHard:
  imagefs.available: 15%
  memory.available: 100Mi
  nodefs.available: 10%
  nodefs.inodesFree: 5%
maxOpenFiles: 1000000
maxPods: 110
EOF

3. 生成bootstrap.kubeconfig文件

KUBE_APISERVER="https://192.168.31.71:6443" # apiserver IP:PORT
TOKEN="c47ffb939f5ca36231d9e3121a252940" # 与token.csv里保持一致

# 生成 kubelet bootstrap kubeconfig 配置文件
kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=bootstrap.kubeconfig
kubectl config set-credentials "kubelet-bootstrap" \
  --token=${TOKEN} \
  --kubeconfig=bootstrap.kubeconfig
kubectl config set-context default \
  --cluster=kubernetes \
  --user="kubelet-bootstrap" \
  --kubeconfig=bootstrap.kubeconfig
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig

拷贝到配置文件路径:

cp bootstrap.kubeconfig /opt/kubernetes/cfg

4. systemd管理kubelet

cat > /usr/lib/systemd/system/kubelet.service << EOF
[Unit]
Description=Kubernetes Kubelet
After=docker.service

[Service]
EnvironmentFile=/opt/kubernetes/cfg/kubelet.conf
ExecStart=/opt/kubernetes/bin/kubelet \$KUBELET_OPTS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

5. 启动并设置开机启动

systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet

5.3 批准kubelet证书申请并加入集群

# 查看kubelet证书请求
kubectl get csr
NAME                                                   AGE    SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A   6m3s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 批准申请
kubectl certificate approve node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A

# 查看节点
kubectl get node
NAME         STATUS     ROLES    AGE   VERSION
k8s-master   NotReady   <none>   7s    v1.18.3

注:由于网络插件还没有部署,节点会没有准备就绪 NotReady

5.4 部署kube-proxy

1. 创建配置文件

cat > /opt/kubernetes/cfg/kube-proxy.conf << EOF
KUBE_PROXY_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--config=/opt/kubernetes/cfg/kube-proxy-config.yml"
EOF

2. 配置参数文件

cat > /opt/kubernetes/cfg/kube-proxy-config.yml << EOF
kind: KubeProxyConfiguration
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 0.0.0.0
metricsBindAddress: 0.0.0.0:10249
clientConnection:
  kubeconfig: /opt/kubernetes/cfg/kube-proxy.kubeconfig
hostnameOverride: k8s-master
clusterCIDR: 10.0.0.0/24
EOF

3. 生成kube-proxy.kubeconfig文件

生成kube-proxy证书:

# 切换工作目录
cd TLS/k8s

# 创建证书请求文件
cat > kube-proxy-csr.json << EOF
{
  "CN": "system:kube-proxy",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing",
      "ST": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}
EOF

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

ls kube-proxy*pem
kube-proxy-key.pem  kube-proxy.pem

生成kubeconfig文件:

KUBE_APISERVER="https://192.168.31.71:6443"

kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/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

拷贝到配置文件指定路径:

cp kube-proxy.kubeconfig /opt/kubernetes/cfg/

4. systemd管理kube-proxy

cat > /usr/lib/systemd/system/kube-proxy.service << EOF
[Unit]
Description=Kubernetes Proxy
After=network.target

[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-proxy.conf
ExecStart=/opt/kubernetes/bin/kube-proxy \$KUBE_PROXY_OPTS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

5. 启动并设置开机启动

systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy

5.5 部署CNI网络

先准备好CNI二进制文件:

下载地址:https://github.com/containernetworking/plugins/releases/download/v0.8.6/cni-plugins-linux-amd64-v0.8.6.tgz

解压二进制包并移动到默认工作目录:

mkdir /opt/cni/bin
tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin

部署CNI网络:

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
sed -i -r "s#quay.io/coreos/flannel:.*-amd64#lizhenliang/flannel:v0.12.0-amd64#g" kube-flannel.yml

默认镜像地址无法访问,修改为docker hub镜像仓库。

kubectl apply -f kube-flannel.yml

kubectl get pods -n kube-system
NAME                          READY   STATUS    RESTARTS   AGE
kube-flannel-ds-amd64-2pc95   1/1     Running   0          72s

kubectl get node
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    <none>   41m   v1.18.3

部署好网络插件,Node准备就绪。

5.6 授权apiserver访问kubelet

cat > apiserver-to-kubelet-rbac.yaml << EOF
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:kube-apiserver-to-kubelet
rules:
  - apiGroups:
      - ""
    resources:
      - nodes/proxy
      - nodes/stats
      - nodes/log
      - nodes/spec
      - nodes/metrics
      - pods/log
    verbs:
      - "*"
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: system:kube-apiserver
  namespace: ""
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:kube-apiserver-to-kubelet
subjects:
  - apiGroup: rbac.authorization.k8s.io
    kind: User
    name: kubernetes
EOF

kubectl apply -f apiserver-to-kubelet-rbac.yaml

5.7 新增加Worker Node

1. 拷贝已部署好的Node相关文件到新节点

在master节点将Worker Node涉及文件拷贝到新节点192.168.31.72/73

scp /opt/kubernetes root@192.168.31.72:/opt/

scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.31.72:/usr/lib/systemd/system

scp -r /opt/cni/ root@192.168.31.72:/opt/

scp /opt/kubernetes/ssl/ca.pem root@192.168.31.72:/opt/kubernetes/ssl

2. 删除kubelet证书和kubeconfig文件

rm /opt/kubernetes/cfg/kubelet.kubeconfig 
rm -f /opt/kubernetes/ssl/kubelet*

注:这几个文件是证书申请审批后自动生成的,每个Node不同,必须删除重新生成。

3. 修改主机名

vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node1

vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-node1

4. 启动并设置开机启动

systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet
systemctl start kube-proxy
systemctl enable kube-proxy

5. 在Master上批准新Node kubelet证书申请

kubectl get csr
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro   89s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

kubectl certificate approve node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro

6. 查看Node状态

kubectl get node
NAME         STATUS     ROLES    AGE   VERSION
k8s-master   Ready      <none>   65m   v1.18.3
k8s-node1    Ready      <none>   12m   v1.18.3
k8s-node2    Ready      <none>   81s   v1.18.3

Node2(192.168.31.73 )节点同上。记得修改主机名!

六、部署Dashboard和CoreDNS

6.1 部署Dashboard

$ wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta8/aio/deploy/recommended.yaml

默认Dashboard只能集群内部访问,修改Service为NodePort类型,暴露到外部:

vi recommended.yaml
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30001
  type: NodePort
  selector:
    k8s-app: kubernetes-dashboard

kubectl apply -f recommended.yaml
kubectl get pods,svc -n kubernetes-dashboard
NAME                                             READY   STATUS              RESTARTS   AGE
pod/dashboard-metrics-scraper-694557449d-z8gfb   1/1     Running             0          2m18s
pod/kubernetes-dashboard-9774cc786-q2gsx         1/1     Running             0          2m19s

NAME                                TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
service/dashboard-metrics-scraper   ClusterIP   10.0.0.141   <none>        8000/TCP        2m19s
service/kubernetes-dashboard        NodePort    10.0.0.239   <none>        443:30001/TCP   2m19s

访问地址:https://NodeIP:30001

创建service account并绑定默认cluster-admin管理员集群角色:

kubectl create serviceaccount dashboard-admin -n kube-system
kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')

使用输出的token登录Dashboard。

部署一套完整的Kubernetes高可用集群(二进制,最新版v1.18)上

部署一套完整的Kubernetes高可用集群(二进制,最新版v1.18)上

6.2 部署CoreDNS

CoreDNS用于集群内部Service名称解析。

kubectl apply -f coredns.yaml

kubectl get pods -n kube-system 
NAME                          READY   STATUS    RESTARTS   AGE
coredns-5ffbfd976d-j6shb      1/1     Running   0          32s
kube-flannel-ds-amd64-2pc95   1/1     Running   0          38m
kube-flannel-ds-amd64-7qhdx   1/1     Running   0          15m
kube-flannel-ds-amd64-99cr8   1/1     Running   0          26m

DNS解析测试:

kubectl run -it --rm dns-test --image=busybox:1.28.4 sh
If you don't see a command prompt, try pressing enter.

/ # nslookup kubernetes
Server:    10.0.0.2
Address 1: 10.0.0.2 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes
Address 1: 10.0.0.1 kubernetes.default.svc.cluster.local

解析没问题。

至此,单Master集群部署完成,下一篇扩容为多Master集群~