Configuring the Docker

You can run commands through the command line or use the service (configured by the configuration file) to start the Docker.

• Run the following command to start Docker:

  docker daemon -D #Start Docker using the commandline. –D enables the commission. If you want to sto the commissionp, kill the Docker process.

• Use the systemd service to start Docker.

  systemctl start docker #Start Docker using the service. If you want to stop the Docker, change start to stop.

  Users can modify the /usr/lib/systemd/system/docker.service file to modify startup parameters of Docker.

  # vim /usr/lib/systemd/system/docker.service
  [Unit]
  Description=Docker Application Container Engine
  Documentation=https://docs.docker.com
  After=network.target
  
  [Service]
  Type=notify
  EnvironmentFile=-/etc/sysconfig/docker
  EnvironmentFile=-/etc/sysconfig/docker-storage
  EnvironmentFile=-/etc/sysconfig/docker-network
  Environment=GOTRACEBACK=crash
  # the default is not to use systemd for cgroups because the delegate issues still
  # exists and systemd currently does not support the cgroup feature set required
  # for containers run by docker
  ExecStart=/usr/bin/docker daemon $OPTIONS \
            $DOCKER_STORAGE_OPTIONS \
            $DOCKER_NETWORK_OPTIONS \
            $ADD_REGISTRY \
            $BLOCK_REGISTRY \
            $INSECURE_REGISTRY
  LimitNOFILE=1048576
  LimitNPROC=1048576
  LimitCORE=infinity
  TimeoutStartSec=0
  # set delegate yes so that systemd does not reset the cgroups of docker containers
  Delegate=yes
  # kill only the docker process, not all processes in the cgroup
  KillMode=process
  
  [Install]
  WantedBy=multi-user.target

  1. Run the systemctl restart docker command to restart the service and make configurations to take effect.
  2. EnvironmentFile=-/etc/sysconfig/docker: defines the file where environment variables locate. Environment variables defined in the file can be quoted in the /usr/lib/systemd /system/docker.service file.
  3. Startup parameters of Docker must be added to the end of ExecStart.

• Configuring external network proxy of Docker.

  If you want to pull images from Docker Hub, you need to set the proxy.

  1. Add following contents to the /usr/lib/systemd/system/docker.service directory:

     Environment="HTTP_PROXY=http://count:passwd@proxyhk.huawei.com:8080"

  2. Run the following command to restart the daemon and make the configuration take effect:

     systemctl restart docker