dockerd: add page (#3349)

pages/linux/dockerd.md

@@ -0,0 +1,24 @@
+# dockerd
+
+> A persistent process to start and manage docker containers.
+> More information: <https://docs.docker.com/engine/reference/commandline/dockerd/>.
+
+- Run docker daemon:
+
+`dockerd`
+
+- Run docker daemon and config it to listen to specific sockets(unix,tcp):
+
+`dockerd --host unix://{{path/to/tmp.sock}} --host tcp://{{ip}}`
+
+- Run with specific daemon PID file:
+
+`dockerd --pidfile {{path/to/pid_file}}`
+
+- Run in debug mode:
+
+`dockerd --debug`
+
+- Run and set a specific log level:
+
+`dockerd --log-level={{debug|info|warn|error|fatal}}`