二进制安装kubernetes v1.11.2 （第十四章 kube-proxy部署）

继续前一章的部署。

部署 kube-proxy 组件

14.1 下载和分发二进制文件，参考 第三章

分发到各节点

source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
  do
    echo ">>> ${node_name}"
    scp k8s/v1.11.2/server/kubernetes/server/bin/{kube-proxy,kubelet} k8s@${node_name}:/opt/k8s/bin/
    ssh k8s@${node_name} "chmod 755 /opt/k8s/bin/{kube-proxy,kubelet}"
done

14.2  安装依赖包，参考 第十一章

14.3 创建 kube-proxy 证书

cd /opt/k8s/cert

cat > kube-proxy-csr.json <<EOF
{
  "CN": "system:kube-proxy",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "4Paradigm"
    }
  ]
}
EOF

• CN：指定该证书的 User 为 system:kube-proxy；
• 预定义的 RoleBinding system:node-proxier 将User system:kube-proxy 与 Role system:node-proxier 绑定，该 Role 授予了调用 kube-apiserver Proxy 相关 API 的权限；
• 该证书只会被 kube-proxy 当做 client 证书使用，所以 hosts 字段为空；

生成证书和私钥:

cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
  -ca-key=/etc/kubernetes/cert/ca-key.pem \
  -config=/etc/kubernetes/cert/ca-config.json \
  -profile=kubernetes  kube-proxy-csr.json | cfssljson -bare kube-proxy

创建和分发 kubeconfig 文件

source /opt/k8s/bin/environment.sh
kubectl config set-cluster kubernetes \
  --certificate-authority=/etc/kubernetes/cert/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

• --embed-certs-true 将 ca.pem和admin.pem 证书内容嵌入到生成的 kubectl-proxy.kubeconfig 文件中（不加时，写入的是证书文件的路径）

分发 kubeconfig 文件

source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
  do
    echo ">>> ${node_name}"
    scp kube-proxy.kubeconfig k8s@${node_name}:/etc/kubernetes/
done

14.3 创建 kube-proxy 配置文件

从 v1.10开始，kube-proxy 部分参数可以在配置文件中配置，可以使用 --write-config-to 选项生成该配置文件，或者参考 kubeproxyconfig 的类型定义源文件：

https://github.com/kubernetes/kubernetes/blob/master/pkg/proxy/apis/kubeproxyconfig/types.go

创建 kube-proxy config 文件模板：

cat >kube-proxy.config.yaml.template <<EOF
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: ##NODE_IP##
clientConnection:
  kubeconfig: /etc/kubernetes/kube-proxy.kubeconfig
clusterCIDR: ${CLUSTER_CIDR}
healthzBindAddress: ##NODE_IP##:10256
hostnameOverride: ##NODE_NAME##
kind: KubeProxyConfiguration
metricsBindAddress: ##NODE_IP##:10249
mode: "ipvs"
EOF

• bindAddress  监听地址
• clientConnect.kubeconfig   连接 apiserver 的 kubeconfig 文件
• clusterCIDR  kube-proxy 根据 --cluster-cidr 判断集群内部和外部流量，指定 --cluster-cidr 或 --masquerade-all 选项后 kube-proxy 才会对访问 Service IP 的请求做 SNAT
• hostnameOverride 参数值必须与 kubelet 的值一致，否则 kube-proxy 启动后会找不到该 Node ，从而不会创建任何 ipvs 规则
• mode 使用 ipvs 模式

为各节点创建和分发 kube-proxy 配置文件

source /opt/k8s/bin/environment.sh
for (( i=0; i < 4; i++ ))
  do 
    echo ">>> ${NODE_NAMES[i]}"
    sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-proxy.config.yaml.template > kube-proxy-${NODE_NAMES[i]}.config.yaml
    scp kube-proxy-${NODE_NAMES[i]}.config.yaml root@${NODE_NAMES[i]}:/etc/kubernetes/kube-proxy.config.yaml
done

替换后的 kube-proxy.config.yaml如下

[root@k8s-n2 kubernetes]# cat /etc/kubernetes/kube-proxy.config.yaml
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 192.168.56.31
clientConnection:
  kubeconfig: /etc/kubernetes/kube-proxy.kubeconfig
clusterCIDR: 172.30.0.0/16
healthzBindAddress: 192.168.56.31:10256
hostnameOverride: k8s-n2
kind: KubeProxyConfiguration
metricsBindAddress: 192.168.56.31:10249
mode: "ipvs"

 

14.4 创建和分发 kube-proxy systemd unit 文件

source /opt/k8s/bin/environment.sh
cat > kube-proxy.service <<EOF
[Unit]
Description=Kubernetes Kube-Proxy Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target

[Service]
WorkingDirectory=/var/lib/kube-proxy
ExecStart=/opt/k8s/bin/kube-proxy \\
  --config=/etc/kubernetes/kube-proxy.config.yaml \\
  --alsologtostderr=true \\
  --logtostderr=false \\
  --log-dir=/var/log/kubernetes \\
  --v=2
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

分发 kube-proxy systemd unit 文件

source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
  do 
    echo ">>> ${node_name}"
    scp kube-proxy.service root@${node_name}:/etc/systemd/system/
done

14.5 启动 kube-proxy 服务

source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh root@${node_ip} "mkdir -p /var/lib/kube-proxy"
    ssh root@${node_ip} "mkdir -p /var/log/kubernetes && chown -R k8s /var/log/kubernetes"
    ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-proxy && systemctl restart kube-proxy"
done

检查启动结果：

source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh k8s@${node_ip} "systemctl status kube-proxy|grep Active"
done

• 确保服务是 Active: active (running) 状态
• 查看日志: journalctl -u kube-proxy

查看监听端口和 metrics

[k8s@k8s-m1 template]$ sudo netstat -lnpt|grep kube-prox
tcp        0      0 192.168.56.20:10249     0.0.0.0:*               LISTEN      729/kube-proxy      
tcp        0      0 192.168.56.20:10256     0.0.0.0:*               LISTEN      729/kube-proxy 

• 10249：http prometheus metrics port;
• 10256：http healthz port;

查看 ipvs 路由规则

[k8s@k8s-m1 template]$ source /opt/k8s/bin/environment.sh
[k8s@k8s-m1 template]$ for node_ip in ${NODE_IPS[@]}
>   do
>     echo ">>> ${node_ip}"
>     ssh root@${node_ip} "/usr/sbin/ipvsadm -ln"
>   done
>>> 192.168.56.20
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  10.254.0.1:443 rr
  -> 192.168.56.20:6443           Masq    1      0          0         
  -> 192.168.56.21:6443           Masq    1      0          0         
>>> 192.168.56.21
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  10.254.0.1:443 rr
  -> 192.168.56.20:6443           Masq    1      0          0         
  -> 192.168.56.21:6443           Masq    1      0          0         
>>> 192.168.56.30
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  10.254.0.1:443 rr
  -> 192.168.56.20:6443           Masq    1      0          0         
  -> 192.168.56.21:6443           Masq    1      0          0         
>>> 192.168.56.31
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  10.254.0.1:443 rr
  -> 192.168.56.20:6443           Masq    1      0          0         
  -> 192.168.56.21:6443           Masq    1      0          0    

可以看到，将所有到 kubernetes cluster ip 443 端口的请求都转发到了 kube-apiserver 的 6443 端口