kubernetes（五）二進制安裝-安裝docker服務

部署docker服務（在master節點上執行）

1. 下載和分發 docker 二進制文件

   cd /opt/k8s/work
   wget https://download.docker.com/linux/static/stable/x86_64/docker-18.09.6.tgz
   tar -xvf docker-18.09.6.tgz

2. 分發二進制文件到全部 worker 節點

   cd /opt/k8s/work
   export node_ip=192.168.0.114
   scp docker/*  root@${node_ip}:/opt/k8s/bin/
   ssh root@${node_ip} "chmod +x /opt/k8s/bin/*"

3. 建立docker服務啓動文件

   cd /opt/k8s/work
   cat > docker.service <<"EOF"
   [Unit]
   Description=Docker Application Container Engine
   Documentation=http://docs.docker.io
   
   [Service]
   WorkingDirectory=/data/k8s/docker
   Environment="PATH=/opt/k8s/bin:/bin:/sbin:/usr/bin:/usr/sbin"
   EnvironmentFile=-/run/flannel/docker
   ExecStart=/opt/k8s/bin/dockerd $DOCKER_NETWORK_OPTIONS
   ExecReload=/bin/kill -s HUP $MAINPID
   Restart=on-failure
   RestartSec=5
   LimitNOFILE=infinity
   LimitNPROC=infinity
   LimitCORE=infinity
   Delegate=yes
   KillMode=process
   
   [Install]
   WantedBy=multi-user.target
   EOF

   • EOF 先後有雙引號，這樣 bash 不會替換文檔中的變量，如 $DOCKER_NETWORK_OPTIONS (這些環境變量是 systemd 負責替換的。)；

   • dockerd 運行時會調用其它 docker 命令，如 docker-proxy，因此須要將 docker 命令所在的目錄加到 PATH 環境變量中；

   • flanneld 啓動時將網絡配置寫入 /run/flannel/docker 文件中，dockerd 啓動前讀取該文件中的環境變量 DOCKER_NETWORK_OPTIONS ，而後設置 docker0 網橋網段；

   • docker 從 1.13 版本開始，可能將 iptables FORWARD chain的默認策略設置爲DROP，從而致使 ping 其它 Node 上的 Pod IP 失敗，遇到這種狀況時，須要手動設置策略爲 ACCEPT：

     export node_ip=192.168.0.114
     ssh root@${node_ip}  "/sbin/iptables -P FORWARD ACCEPT"

4. 分發 docker.service 文件到全部 worker 機器:

   cd /opt/k8s/work
   export node_ip=192.168.0.114
   scp docker.service root@${node_ip}:/etc/systemd/system/

5. 配置和分發 docker 配置文件

   使用國內的倉庫鏡像服務器以加快 pull image 的速度，同時增長下載的併發數 (須要重啓 dockerd 生效)：

   cd /opt/k8s/work
   cat > docker-daemon.json <<EOF
   {
       "registry-mirrors": ["https://docker.mirrors.ustc.edu.cn","https://hub-mirror.c.163.com"],
       "max-concurrent-downloads": 20,
       "live-restore": true,
       "max-concurrent-uploads": 10,
       "data-root": "/data/k8s/docker/data",
       "log-opts": {
         "max-size": "100m",
         "max-file": "5"
       }
   }
   EOF

6. 分發 docker 配置文件到全部 worker 節點：

   cd /opt/k8s/work
   
   export node_ip=192.168.0.114
   ssh root@${node_ip} "mkdir -p  /etc/docker/ /data/k8s/docker/data"
   scp docker-daemon.json root@${node_ip}:/etc/docker/daemon.json

7. 啓動 docker 服務

   export node_ip=192.168.0.114
   ssh root@${node_ip} "systemctl daemon-reload && systemctl enable docker && systemctl restart docker"

8. 檢查服務運行狀態

   export node_ip=192.168.0.114
   ssh root@${node_ip} "systemctl status docker|grep Active"

   • 確保狀態爲 active (running)，不然查看日誌，確認緣由

   • 若是出現異常，經過以下命令查看

     journalctl -u docker

9. 檢查 docker0 網橋

   export node_ip=192.168.0.114
   ssh root@${node_ip} "/sbin/ip addr show flannel.1 && /sbin/ip addr show docker0"

   • 確認各 worker 節點的 docker0 網橋和 flannel.1 接口的 IP 處於同一個網段中

     輸出內容

     export node_ip=192.168.0.114
     root@master:/opt/k8s/work# ssh root@${node_ip} "/sbin/ip addr show flannel.1 && /sbin/ip addr show docker0"
     4: flannel.1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UNKNOWN group default
         link/ether f2:fc:0f:7e:98:e4 brd ff:ff:ff:ff:ff:ff
         inet 172.30.78.0/32 scope global flannel.1
            valid_lft forever preferred_lft forever
         inet6 fe80::f0fc:fff:fe7e:98e4/64 scope link
            valid_lft forever preferred_lft forever
     5: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
         link/ether 02:42:fd:1f:8f:d8 brd ff:ff:ff:ff:ff:ff
         inet 172.30.78.1/24 brd 172.30.78.255 scope global docker0
            valid_lft forever preferred_lft forever

   • 注意: 若是您的服務安裝順序不對或者機器環境比較複雜, docker服務早於flanneld服務安裝，此時 worker 節點的 docker0 網橋和 flannel.1 接口的 IP可能不會同處同一個網段下，這個時候請先中止docker服務, 手工刪除docker0網卡，從新啓動docker服務後便可修復

     systemctl stop docker
     ip link delete docker0
     systemctl start docker

10. 查看 docker 的狀態信息

    root@slave:/opt/k8s/work# docker info
    Containers: 0
     Running: 0
     Paused: 0
     Stopped: 0
    Images: 0
    Server Version: 18.09.6
    Storage Driver: overlay2
     Backing Filesystem: extfs
     Supports d_type: true
     Native Overlay Diff: true
    Logging Driver: json-file
    Cgroup Driver: cgroupfs
    Plugins:
     Volume: local
     Network: bridge host macvlan null overlay
     Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
    Swarm: inactive
    Runtimes: runc
    Default Runtime: runc
    Init Binary: docker-init
    containerd version: bb71b10fd8f58240ca47fbb579b9d1028eea7c84
    runc version: 2b18fe1d885ee5083ef9f0838fee39b62d653e30
    init version: fec3683
    Security Options:
     apparmor
     seccomp
      Profile: default
    Kernel Version: 5.0.0-23-generic
    Operating System: Ubuntu 18.04.3 LTS
    OSType: linux
    Architecture: x86_64
    CPUs: 4
    Total Memory: 3.741GiB
    Name: slave
    ID: IDMG:7A6F:UNTP:IWVM:ZBK5:VHJ4:STC5:UXZX:HQT6:UUNE:YDOC:I27L
    Docker Root Dir: /data/k8s/docker/data
    Debug Mode (client): false
    Debug Mode (server): false
    Registry: https://index.docker.io/v1/
    Labels:
    Experimental: false
    Insecure Registries:
     127.0.0.0/8
    Registry Mirrors:
     https://docker.mirrors.ustc.edu.cn/
     https://hub-mirror.c.163.com/
    Live Restore Enabled: true
    Product License: Community Engine
    
    WARNING: No swap limit support