一 部署docker

1.1 部署docker元件

docker 執行和管理容器，kubelet 通過 Container Runtime Interface (CRI) 與它進行互動。

1.2 下載docker

  1 [root@k8smaster01 ~]# cd /opt/k8s/work
  2 [root@k8smaster01 work]# wget https://download.docker.com/linux/static/stable/x86_64/docker-18.09.6.tgz
  3 [root@k8smaster01 work]# tar -xvf docker-18.09.6.tgz

提示：更多docker版本下載參考https://download.docker.com/linux/static/stable/x86_64/。

1.3 安裝和部署docker

  1 [root@k8smaster01 ~]# cd /opt/k8s/work
  2 [root@k8smaster01 work]# source /opt/k8s/bin/environment.sh
  3 [root@k8smaster01 work]# for all_ip in ${ALL_IPS[@]}
  4   do
  5     echo ">>> ${all_ip}"
  6     scp docker/*  root@${all_ip}:/opt/k8s/bin/
  7     ssh root@${all_ip} "chmod +x /opt/k8s/bin/*"
  8   done

1.4 配置docker system

  1 [root@k8smaster01 ~]# cd /opt/k8s/work
  2 [root@k8smaster01 work]# cat > docker.service <<"EOF"
  3 [Unit]
  4 Description=Docker Application Container Engine
  5 Documentation=http://docs.docker.io
  6 
  7 [Service]
  8 WorkingDirectory=##DOCKER_DIR##
  9 Environment="PATH=/opt/k8s/bin:/bin:/sbin:/usr/bin:/usr/sbin"
 10 EnvironmentFile=-/run/flannel/docker
 11 ExecStart=/opt/k8s/bin/dockerd $DOCKER_NETWORK_OPTIONS
 12 ExecReload=/bin/kill -s HUP $MAINPID
 13 Restart=on-failure
 14 RestartSec=5
 15 LimitNOFILE=infinity
 16 LimitNPROC=infinity
 17 LimitCORE=infinity
 18 Delegate=yes
 19 KillMode=process
 20 
 21 [Install]
 22 WantedBy=multi-user.target
 23 EOF

解釋：

• EOF 前後有雙引號，這樣 bash 不會替換文件中的變數，如 $DOCKER_NETWORK_OPTIONS (這些環境變數是 systemd 負責替換的。)；
• dockerd 執行時會呼叫其它 docker 命令，如 docker-proxy，所以需要將 docker 命令所在的目錄加到 PATH 環境變數中；
• flanneld 啟動時將網路配置寫入 /run/flannel/docker 檔案中，dockerd 啟動前讀取該檔案中的環境變數 DOCKER_NETWORK_OPTIONS ，然後設定 docker0 網橋網段；
• 如果指定了多個 EnvironmentFile 選項，則必須將 /run/flannel/docker 放在最後(確保 docker0 使用 flanneld 生成的 bip 引數)；
• docker 需要以 root 用於執行；
• docker 從 1.13 版本開始，可能將 iptables FORWARD chain的預設策略設定為DROP，從而導致 ping 其它 Node 上的 Pod IP 失敗，遇到這種情況時，需要手動設定策略為 ACCEPT：

  1 [root@k8smaster01 ~]# echo '/sbin/iptables -P FORWARD ACCEPT' >> /etc/rc.local

並且把以下命令寫入 /etc/rc.local 檔案中，防止節點重啟iptables FORWARD chain的預設策略又還原為DROP

1.5 分發docker systemd

  1 [root@k8smaster01 ~]# cd /opt/k8s/work
  2 [root@k8smaster01 work]# source /opt/k8s/bin/environment.sh
  3 [root@k8smaster01 work]# sed -i -e "s|##DOCKER_DIR##|${DOCKER_DIR}|" docker.service
  4 [root@k8smaster01 work]# for all_ip in ${ALL_IPS[@]}
  5   do
  6     echo ">>> ${all_ip}"
  7     scp docker.service root@${all_ip}:/etc/systemd/system/
  8   done

1.6 配置docker配置檔案

  1 [root@k8smaster01 ~]# cd /opt/k8s/work
  2 [root@k8smaster01 work]# source /opt/k8s/bin/environment.sh
  3 [root@k8smaster01 work]# cat > docker-daemon.json <<EOF
  4 {
  5     "registry-mirrors": ["https://docker.mirrors.ustc.edu.cn","https://hub-mirror.c.163.com"],
  6     "insecure-registries": ["docker02:35000"],
  7     "max-concurrent-downloads": 20,
  8     "live-restore": true,
  9     "max-concurrent-uploads": 10,
 10     "debug": true,
 11     "data-root": "${DOCKER_DIR}/data",
 12     "exec-root": "${DOCKER_DIR}/exec",
 13     "log-opts": {
 14       "max-size": "100m",
 15       "max-file": "5"
 16     }
 17 }
 18 EOF

1.7 分發docker配置檔案

  1 [root@k8smaster01 ~]# cd /opt/k8s/work
  2 [root@k8smaster01 work]# source /opt/k8s/bin/environment.sh
  3 [root@k8smaster01 work]# for all_ip in ${ALL_IPS[@]}
  4   do
  5     echo ">>> ${all_ip}"
  6     ssh root@${all_ip} "mkdir -p /etc/docker/ ${DOCKER_DIR}/{data,exec}"
  7     scp docker-daemon.json root@${all_ip}:/etc/docker/daemon.json
  8   done

二 啟動並驗證

2.1 啟動docker

  1 [root@k8smaster01 ~]# source /opt/k8s/bin/environment.sh
  2 [root@k8smaster01 ~]# for all_ip in ${ALL_IPS[@]}
  3   do
  4     echo ">>> ${all_ip}"
  5     ssh root@${all_ip} "systemctl daemon-reload && systemctl enable docker && systemctl restart docker"
  6   done

2.2 檢查docker服務

  1 [root@k8smaster01 ~]# source /opt/k8s/bin/environment.sh
  2 [root@k8smaster01 ~]# for all_ip in ${ALL_IPS[@]}
  3   do
  4     echo ">>> ${all_ip}"
  5     ssh root@${all_ip} "systemctl status docker|grep Active"
  6   done

2.3 檢查docker 0網橋

  1 [root@k8smaster01 ~]# source /opt/k8s/bin/environment.sh
  2 [root@k8smaster01 ~]# for all_ip in ${ALL_IPS[@]}
  3   do
  4     echo ">>> ${all_ip}"
  5     ssh root@${all_ip} "/usr/sbin/ip addr show flannel.1 && /usr/sbin/ip addr show docker0"
  6   done

提示：確認各 worker 節點的 docker0 網橋和 flannel.1 介面的 IP 處於同對應的相同網段中。

2.4 檢視docker資訊

  1 [root@k8smaster01 ~]# ps -elfH|grep docker | grep -v grep
  2 [root@k8smaster01 ~]# docker info