docker笔记（9）—— 通过systemd管理docker

包括RHEL在内的很多Linux操作系统通过systemd管理docker。例如启动和停止docker daemon：

# systemctl start docker
# systemctl stop docker

另外，可以使用systemctl status docker检查目前docker daemon的运行状态：

# systemctl status docker
● docker.service - Docker Application Container Engine
   Loaded: loaded (/lib/systemd/system/docker.service; enabled)
  Drop-In: /etc/systemd/system/docker.service.d
           └─http-proxy.conf
   Active: active (running) since Mon 2016-03-28 23:04:48 EDT; 21min ago
     Docs: https://docs.docker.com
 Main PID: 64991 (docker)
   CGroup: /system.slice/docker.service
           └─64991 /usr/bin/docker daemon -D -H fd://

Mar 28 23:08:51 lxc-dl980-g7-1-hLinux docker[64991]: time="2016-03-28T23:08:51.685679667-04:00" level=debug msg="devmapper: Delete...START"
Mar 28 23:08:51 lxc-dl980-g7-1-hLinux docker[64991]: time="2016-03-28T23:08:51.688765554-04:00" level=debug msg="devmapper: issueD...START"
Mar 28 23:08:51 lxc-dl980-g7-1-hLinux docker[64991]: time="2016-03-28T23:08:51.689292872-04:00" level=debug msg="devmapper: activa...c9f6)"
Mar 28 23:08:53 lxc-dl980-g7-1-hLinux docker[64991]: time="2016-03-28T23:08:53.050572512-04:00" level=debug msg="devmapper: issueD.... END"
.....

配置文件是/lib/systemd/system/docker.service，修改这个文件后要记得使用systemctl daemon-reload命令重新加载一下。

systemctl show docker命令显示docker的各种配置信息：

~# systemctl show docker
Type=notify
Restart=no
NotifyAccess=main
RestartUSec=100ms
TimeoutStartUSec=0
TimeoutStopUSec=1min 30s
WatchdogUSec=0
WatchdogTimestampMonotonic=0
StartLimitInterval=10000000
StartLimitBurst=5
StartLimitAction=none
FailureAction=none
PermissionsStartOnly=no
......

关于如何使用journalctl查看log，可以参考https://www.loggly.com/ultimate-guide/using-journalctl/。

绑定service和运行的CPU：https://www.golinuxhub.com/2018/02/how-to-assign-service-to-specific-core/ 。

参考资料：
Control and configure Docker with systemd。