Ejecutamos systemctl status docker.service para mostrar la información del estado del servicio.
docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: failed (Result: protocol) since Fri 2017-12-29 10:05:40 CET; 2min 14s ago
Docs: https://docs.docker.com
Process: 14862 ExecStart=/usr/bin/dockerd -H fd:// (code=exited, status=1/FAILURE)
Main PID: 14862 (code=exited, status=1/FAILURE)
CPU: 43ms
dic 29 10:05:40 Dell-XPS-8900 systemd[1]: docker.service: Unit entered failed state.
dic 29 10:05:40 Dell-XPS-8900 systemd[1]: docker.service: Failed with result 'protocol'.
dic 29 10:05:40 Dell-XPS-8900 systemd[1]: docker.service: Service hold-off time over, scheduling restart.
dic 29 10:05:40 Dell-XPS-8900 systemd[1]: Stopped Docker Application Container Engine.
dic 29 10:05:40 Dell-XPS-8900 systemd[1]: docker.service: Start request repeated too quickly.
dic 29 10:05:40 Dell-XPS-8900 systemd[1]: Failed to start Docker Application Container Engine.
dic 29 10:05:40 Dell-XPS-8900 systemd[1]: docker.service: Unit entered failed state.
dic 29 10:05:40 Dell-XPS-8900 systemd[1]: docker.service: Failed with result 'protocol'.
A continuación Ejecutamos journalctl -xe para ver los logs del sistema.
dic 29 10:05:40 Dell-XPS-8900 systemd[1]: Starting Docker Application Container Engine... -- Subject: Unit docker.service has begun start-up -- Defined-By: systemd -- Support: http://www.ubuntu.com/support -- -- Unit docker.service has begun starting up. dic 29 10:05:40 Dell-XPS-8900 dockerd[14862]: ERROR: The 'disable-legacy-registry' configuration option has been removed. Interacting with legacy (v1) registries is no longer supported dic 29 10:05:40 Dell-XPS-8900 systemd[1]: docker.service: Main process exited, code=exited, status=1/FAILURE dic 29 10:05:40 Dell-XPS-8900 systemd[1]: Failed to start Docker Application Container Engine. -- Subject: Unit docker.service has failed -- Defined-By: systemd -- Support: http://www.ubuntu.com/support -- -- Unit docker.service has failed. -- -- The result is failed. dic 29 10:05:40 Dell-XPS-8900 systemd[1]: docker.service: Unit entered failed state. dic 29 10:05:40 Dell-XPS-8900 systemd[1]: docker.service: Failed with result 'protocol'. dic 29 10:05:40 Dell-XPS-8900 systemd[1]: docker.service: Service hold-off time over, scheduling restart. dic 29 10:05:40 Dell-XPS-8900 systemd[1]: Stopped Docker Application Container Engine.
Aquí se puede ver el motivo real del problema:
ERROR: The 'disable-legacy-registry' configuration option has been removed. Interacting with legacy (v1) registries is no longer supported
En el post Conectar a un Docker Registry inseguro en Ubuntu con Docker v17.06+ explicaba precisamente que una solución para acceder a un registry no securizado era modificar el fichero /etc/docker/daemon.json y añadir la línea:
"disable-legacy-registry": false,
Pues por lo visto esta opción de configuración ha sido deprecada en la versión actual de docker (17.12).
Se puede comprobar en el siguiente enlace.
Saludos