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Kubernetes - 二进制版本安装 - v1.18

汪洋
2021-09-03 / 0 评论 / 8 点赞 / 2,180 阅读 / 31,959 字

一、准备环境

单Master服务器规划:

角色IP组件
k8s-master192.168.31.71kube-apiserver,kube-controller-manager,kube-scheduler,etcd
k8s-node1192.168.31.72kubelet,kube-proxy,docker etcd
k8s-node2192.168.31.73kubelet,kube-proxy,docker,etcd

二、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

三、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-1192.168.31.71
etcd-2192.168.31.72
etcd-3192.168.31.73

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。

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
生成Etcd证书
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
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
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

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

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/
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
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
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/
启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start etcd
$ systemctl enable etcd
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/ [email protected]:/opt/
$ scp /usr/lib/systemd/system/etcd.service [email protected]:/usr/lib/systemd/system/
$ scp -r /opt/etcd/ [email protected]:/opt/
$ scp /usr/lib/systemd/system/etcd.service [email protected]:/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

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

四、安装 Docker

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

解压二进制包
$ tar zxvf docker-19.03.9.tgz
$ mv docker/* /usr/bin
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
创建配置文件
$ mkdir /etc/docker
$ cat > /etc/docker/daemon.json << EOF
{
  "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF
启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start docker
$ systemctl enable docker

五、部署 Master 角色

生成 kube-apiserver 证书
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
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
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。

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/
部署 kube-apiserver
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
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/
启用 TLS Bootstrapping 机制

LS 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

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 ' '
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
启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start kube-apiserver
$ systemctl enable kube-apiserver
授权 kubelet-bootstrap 用户允许请求证书
$ kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap
部署 kube-controller-manager
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
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
启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start kube-controller-manager
$ systemctl enable kube-controller-manager
部署 kube-scheduler
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)
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
启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start kube-scheduler
$ systemctl enable kube-scheduler
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"}

六、部署Worker Node

下面还是在Master Node上操作,即同时作为Worker Node

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
部署kubelet
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
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
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
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
启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start kubelet
$ systemctl enable kubelet
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

部署 kube-proxy
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
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
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/
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
启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start kube-proxy
$ systemctl enable kube-proxy
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
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
新增加 Worker Node
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 [email protected]:/opt/
 
$ scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service [email protected]:/usr/lib/systemd/system
 
$ scp -r /opt/cni/ [email protected]:/opt/
 
$ scp /opt/kubernetes/ssl/ca.pem [email protected]:/opt/kubernetes/ssl
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

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
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
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
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

七、部署 CoreDNS

修改配置文件
下载解压
$ cd /opt/k8s/work/kubernetes/
$ tar -xzvf kubernetes-src.tar.gz
修改配置
$ cd /opt/k8s/work/kubernetes/cluster/addons/dns/coredns
$ cp coredns.yaml.base coredns.yaml
$ source /opt/k8s/bin/environment.sh
$ sed -i -e "s/__PILLAR__DNS__DOMAIN__/${CLUSTER_DNS_DOMAIN}/" -e "s/__PILLAR__DNS__SERVER__/${CLUSTER_DNS_SVC_IP}/" coredns.yaml
$ vi coredns.yaml
    ……
            image: registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.3.1
    ……
    #修改image的源
创建 coredns
创建 coredns 并检查
$ kubectl create -f coredns.yaml
检查 coredns 功能
$ kubectl get all -n kube-system

八、高可用架构(扩容多 Master 架构)

Kubernetes 作为容器集群系统,通过健康检查+重启策略实现了 Pod 故障自我修复能力,通过调度算法实现将 Pod 分布式部署,并保持预期副本数,根据 Node 失效状态自动在其他 Node 拉起 Pod,实现了应用层的高可用性。针对 Kubernetes 集群,高可用性还应包含以下两个层面的考虑:Etcd 数据库的高可用性和 Kubernetes Master 组件的高可用性。 而 Etcd 我们已经采用 3 个节点组建集群实现高可用,本节将对 Master 节点高可用进行说明和实施。Master 节点扮演着总控中心的角色,通过不断与工作节点上的 Kubelet 和 kube-proxy 进行通信来维护整个集群的健康工作状态。如果 Master 节点故障,将无法使用 kubectl 工具或者 API 做任何集群管理。Master 节点主要有三个服务 kube-apiserver、kube-controller-manager 和 kube-scheduler,其中 kube-controller-manager 和 kube-scheduler 组件自身通过选择机制已经实现了高可用,所以 Master 高可用主要针对 kube-apiserver 组件,而该组件是以 HTTP API 提供服务,因此对他高可用与 Web 服务器类似,增加负载均衡器对其负载均衡即可,并且可水平扩容

安装 Docker

同上,不再赘述

部署 Master2 Node(192.168.31.74)

Master2 与已部署的 Master1 所有操作一致。所以我们只需将 Master1 所有 K8s 文件拷贝过来,再修改下服务器 IP 和主机名启动即可

创建 etcd 证书目录

在 Master2 创建 etcd 证书目录

$ mkdir -p /opt/etcd/ssl
拷贝文件( Master1 操作)

拷贝 Master1 上所有 K8s 文件和 etcd 证书到 Master2

$ scp -r /opt/kubernetes [email protected]:/opt
$ scp -r /opt/cni/ [email protected]:/opt
$ scp -r /opt/etcd/ssl [email protected]:/opt/etcd
$ scp /usr/lib/systemd/system/kube* [email protected]:/usr/lib/systemd/system
$ scp /usr/bin/kubectl  [email protected]:/usr/bin
删除证书文件

删除 kubelet 证书和 kubeconfig 文件

$ rm -f /opt/kubernetes/cfg/kubelet.kubeconfig 
$ rm -f /opt/kubernetes/ssl/kubelet*
修改配置文件IP和主机名

修改 apiserver、kubelet 和 kube-proxy 配置文件为本地 IP

$ vi /opt/kubernetes/cfg/kube-apiserver.conf 
  ...
  --bind-address=192.168.31.74 \
  --advertise-address=192.168.31.74 \
  ...
 
$ vi /opt/kubernetes/cfg/kubelet.conf
	--hostname-override=k8s-master2
 
$ vi /opt/kubernetes/cfg/kube-proxy-config.yml
	hostnameOverride: k8s-master2
启动设置开机启动
$ systemctl daemon-reload
$ systemctl start kube-apiserver
$ systemctl start kube-controller-manager
$ systemctl start kube-scheduler
$ systemctl start kubelet
$ systemctl start kube-proxy
$ systemctl enable kube-apiserver
$ systemctl enable kube-controller-manager
$ systemctl enable kube-scheduler
$ systemctl enable kubelet
$ systemctl enable kube-proxy
查看集群状态
$ kubectl get cs
    NAME                 STATUS    MESSAGE             ERROR
    scheduler            Healthy   ok                  
    controller-manager   Healthy   ok                  
    etcd-1               Healthy   {"health":"true"}   
    etcd-2               Healthy   {"health":"true"}   
    etcd-0               Healthy   {"health":"true"}
批准 kubelet 证书申请
$ kubectl get csr
    NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
    node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU   85m   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending
 
$ kubectl certificate approve node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU
 
$ kubectl get node
    NAME          STATUS   ROLES    AGE   VERSION
    k8s-master    Ready    <none>   34h   v1.18.3
    k8s-master2   Ready    <none>   83m   v1.18.3
    k8s-node1     Ready    <none>   33h   v1.18.3
    k8s-node2     Ready    <none>   33h   v1.18.3
部署 Nginx 负载均衡器

  • Nginx 是一个主流 Web 服务和反向代理服务器,这里用四层实现对 apiserver 实现负载均衡
  • Keepalived 是一个主流高可用软件,基于 VIP 绑定实现服务器双机热备,在上述拓扑中,Keepalived 主要根据 Nginx 运行状态判断是否需要故障转移(偏移 VIP ),例如当 Nginx 主节点挂掉,VIP 会自动绑定在 Nginx备节点,从而保证 VIP 一直可用,实现 Nginx 高可用
安装软件包(主/备)
$ yum install epel-release -y
$ yum install keepalived -y

$ cd /nginx-1.16.0
$ ./configure --prefix=/usr/local/nginx --with-http_stub_status_module --with-http_ssl_module --with-stream
Nginx 配置文件(主/备一样)
$ cat > /etc/nginx/nginx.conf << "EOF"
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
 
include /usr/share/nginx/modules/*.conf;
 
events {
    worker_connections 1024;
}
 
# 四层负载均衡,为两台Master apiserver组件提供负载均衡
stream {
 
    log_format  main  '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent';
 
    access_log  /var/log/nginx/k8s-access.log  main;
 
    upstream k8s-apiserver {
       server 192.168.31.71:6443;   # Master1 APISERVER IP:PORT
       server 192.168.31.74:6443;   # Master2 APISERVER IP:PORT
    }
 
    server {
       listen 6443;
       proxy_pass k8s-apiserver;
    }
}
 
http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';
 
    access_log  /var/log/nginx/access.log  main;
 
    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   65;
    types_hash_max_size 2048;
 
    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;
 
    server {
        listen       80 default_server;
        server_name  _;
 
        location / {
        }
    }
}
EOF
keepalived 配置文件(Nginx Master)
$ cat > /etc/keepalived/keepalived.conf << EOF
global_defs { 
   notification_email { 
     [email protected] 
     [email protected] 
     [email protected] 
   } 
   notification_email_from [email protected]  
   smtp_server 127.0.0.1 
   smtp_connect_timeout 30 
   router_id NGINX_MASTER
} 
 
vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"
}
 
vrrp_instance VI_1 { 
    state MASTER 
    interface ens33  # 修改为实际网卡名
    virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的 
    priority 100    # 优先级,备服务器设置 90 
    advert_int 1    # 指定VRRP 心跳包通告间隔时间,默认1秒 
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    # 虚拟IP
    virtual_ipaddress { 
        192.168.31.88/24
    } 
    track_script {
        check_nginx
    } 
}
EOF
  • vrrp_script:指定检查nginx工作状态脚本(根据nginx状态判断是否故障转移)
  • virtual_ipaddress:虚拟IP(VIP)
检查 nginx 状态脚本
$ cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ps -ef |grep nginx |egrep -cv "grep|$$")
 
if [ "$count" -eq 0 ];then
    exit 1
else
    exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh
keepalived 配置文件(Nginx Backup)
cat > /etc/keepalived/keepalived.conf << EOF
global_defs { 
   notification_email { 
     [email protected] 
     [email protected] 
     [email protected] 
   } 
   notification_email_from [email protected]  
   smtp_server 127.0.0.1 
   smtp_connect_timeout 30 
   router_id NGINX_BACKUP
} 
 
vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"
}
 
vrrp_instance VI_1 { 
    state BACKUP 
    interface ens33
    virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的 
    priority 90
    advert_int 1
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    virtual_ipaddress { 
        192.168.31.88/24
    } 
    track_script {
        check_nginx
    } 
}
EOF

上述配置文件中检查 nginx 运行状态脚本

$ cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ps -ef |grep nginx |egrep -cv "grep|$$")
 
if [ "$count" -eq 0 ];then
    exit 1
else
    exit 0
fi
EOF

$ chmod +x /etc/keepalived/check_nginx.sh

注:keepalived 根据脚本返回状态码( 0 为工作正常,非 0 不正常)判断是否故障转移

启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start nginx
$ systemctl start keepalived
$ systemctl enable nginx
$ systemctl enable keepalived
查看 keepalived 工作状态
$ ip a
  1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
      link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
      inet 127.0.0.1/8 scope host lo
         valid_lft forever preferred_lft forever
      inet6 ::1/128 scope host 
         valid_lft forever preferred_lft forever
  2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
      link/ether 00:0c:29:04:f7:2c brd ff:ff:ff:ff:ff:ff
      inet 192.168.31.80/24 brd 192.168.31.255 scope global noprefixroute ens33
         valid_lft forever preferred_lft forever
      inet 192.168.31.88/24 scope global secondary ens33
         valid_lft forever preferred_lft forever
      inet6 fe80::20c:29ff:fe04:f72c/64 scope link 
         valid_lft forever preferred_lft forever
         
# 可以看到,在 ens33 网卡绑定了 192.168.31.88 虚拟 IP,说明工作正常
Nginx+Keepalived 高可用测试
# 关闭主节点 Nginx,测试 VIP 是否漂移到备节点服务器
# 在 Nginx Master 执行 pkill nginx
# 在 Nginx Backup,ip addr命令查看已成功绑定 VIP
访问负载均衡器测试

找 K8s 集群中任意一个节点,使用 curl 查看 K8s 版本测试,使用 VIP 访问

$ curl -k https://192.168.31.88:6443/version
{
  "major": "1",
  "minor": "18",
  "gitVersion": "v1.18.3",
  "gitCommit": "2e7996e3e2712684bc73f0dec0200d64eec7fe40",
  "gitTreeState": "clean",
  "buildDate": "2020-05-20T12:43:34Z",
  "goVersion": "go1.13.9",
  "compiler": "gc",
  "platform": "linux/amd64"
}

可以正确获取到 K8s 版本信息,说明负载均衡器搭建正常。该请求数据流程:curl -> vip(nginx) -> apiserver。通过查看 Nginx 日志也可以看到转发 apiserver IP

$ tail /var/log/nginx/k8s-access.log -f
  192.168.31.81 192.168.31.71:6443 - [30/May/2020:11:15:10 +0800] 200 422
  192.168.31.81 192.168.31.74:6443 - [30/May/2020:11:15:26 +0800] 200 422
修改所有 Worker Node 连接 LB VIP

试想下,虽然我们增加了 Master2 和负载均衡器,但是我们是从单 Master 架构扩容的,也就是说目前所有的Node 组件连接都还是 Master1,如果不改为连接 VIP 走负载均衡器,那么 Master 还是单点故障。因此接下来就是要改所有 Node 组件配置文件,由原来 192.168.31.71 修改为 192.168.31.88(VIP)

在所有 Worker Node 执行

$ sed -i 's#192.168.31.71:6443#192.168.31.88:6443#' /opt/kubernetes/cfg/*
$ systemctl restart kubelet
$ systemctl restart kube-proxy
检查节点状态
$ kubectl get node
    NAME          STATUS   ROLES    AGE    VERSION
    k8s-master    Ready    <none>   34h    v1.18.3
    k8s-master2   Ready    <none>   101m   v1.18.3
    k8s-node1     Ready    <none>   33h    v1.18.3
    k8s-node2     Ready    <none>   33h    v1.18.3
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