运行 docker daemon

Docker daemon 是服务器组件，以 Linux 后台服务的方式运行

[root@bogon docker_zk]# systemctl status docker.service
● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
   Active: inactive (dead)
     Docs: https://docs.docker.com
[root@bogon docker_zk]# systemctl start docker.service
[root@bogon docker_zk]# systemctl status docker.service
● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
   Active: active (running) since Tue 2022-08-16 05:28:17 CST; 11s ago
     Docs: https://docs.docker.com
 Main PID: 2107 (dockerd)
    Tasks: 7
   Memory: 125.7M
   CGroup: /system.slice/docker.service
           └─2107 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock

Aug 16 05:28:16 bogon dockerd[2107]: time="2022-08-16T05:28:16.269635335+08:00" level=info msg="scheme \"unix\" not registered, fallback to default scheme" module=grpc
Aug 16 05:28:16 bogon dockerd[2107]: time="2022-08-16T05:28:16.269646903+08:00" level=info msg="ccResolverWrapper: sending update to cc: {[{unix:///run/co...odule=grpc
Aug 16 05:28:16 bogon dockerd[2107]: time="2022-08-16T05:28:16.269653214+08:00" level=info msg="ClientConn switching balancer to \"pick_first\"" module=grpc
Aug 16 05:28:16 bogon dockerd[2107]: time="2022-08-16T05:28:16.308857273+08:00" level=info msg="Loading containers: start."
Aug 16 05:28:16 bogon dockerd[2107]: time="2022-08-16T05:28:16.630618223+08:00" level=info msg="Default bridge (docker0) is assigned with an IP address 17...P address"
Aug 16 05:28:16 bogon dockerd[2107]: time="2022-08-16T05:28:16.742797910+08:00" level=info msg="Loading containers: done."
Aug 16 05:28:17 bogon dockerd[2107]: time="2022-08-16T05:28:17.010787099+08:00" level=info msg="Docker daemon" commit=a89b842 graphdriver(s)=overlay2 version=20.10.17
Aug 16 05:28:17 bogon dockerd[2107]: time="2022-08-16T05:28:17.010892235+08:00" level=info msg="Daemon has completed initialization"
Aug 16 05:28:17 bogon dockerd[2107]: time="2022-08-16T05:28:17.047786928+08:00" level=info msg="API listen on /var/run/docker.sock"
Aug 16 05:28:17 bogon systemd[1]: Started Docker Application Container Engine.
Hint: Some lines were ellipsized, use -l to show in full.
[root@bogon docker_zk]#

Docker daemon 运行在 Docker host 上，负责创建、运行、监控容器，构建、存储镜像。

配置 docker 后台服务开机自启动

[root@zk0 ~]# systemctl enable docker.service
Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.
[root@zk0 ~]# systemctl status docker.service
● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
   Active: inactive (dead)
     Docs: https://docs.docker.com
[root@zk0 ~]#