记一次故障系列：docker 启动失败

启动报错：

]# systemctl start docker
Job for docker.service failed because start of the service was attempted too often. See "systemctl status docker.service" and "journalctl -xe" for details.
To force a start use "systemctl reset-failed docker.service" followed by "systemctl start docker.service" again.

]# journalctl  -xe
2月 25 17:48:31 host-flb systemd[1]: docker.service holdoff time over, scheduling restart.
2月 25 17:48:31 host-flb systemd[1]: Stopped Docker Application Container Engine.
-- Subject: Unit docker.service has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit docker.service has finished shutting down.
2月 25 17:48:31 host-flb systemd[1]: Closed Docker Socket for the API.
-- Subject: Unit docker.socket has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit docker.socket has finished shutting down.
2月 25 17:48:31 host-flb systemd[1]: Stopping Docker Socket for the API.
-- Subject: Unit docker.socket has begun shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit docker.socket has begun shutting down.
2月 25 17:48:31 host-flb systemd[1]: Starting Docker Socket for the API.
-- Subject: Unit docker.socket has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit docker.socket has begun starting up.
2月 25 17:48:31 host-flb systemd[1]: Listening on Docker Socket for the API.
-- Subject: Unit docker.socket has finished start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit docker.socket has finished starting up.
-- 
-- The start-up result is done.
2月 25 17:48:31 host-flb systemd[1]: Starting Docker Application Container Engine...
-- Subject: Unit docker.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit docker.service has begun starting up.
2月 25 17:48:31 host-flb dockerd[29067]: unable to configure the Docker daemon with file /etc/docker/daemon.json: EOF
2月 25 17:48:31 host-flb systemd[1]: docker.service: main process exited, code=exited, status=1/FAILURE
2月 25 17:48:31 host-flb systemd[1]: Failed to start Docker Application Container Engine.
-- Subject: Unit docker.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit docker.service has failed.
-- 
-- The result is failed.
2月 25 17:48:31 host-flb systemd[1]: Unit docker.service entered failed state.
2月 25 17:48:31 host-flb systemd[1]: docker.service failed.

　　

问题原因：

　　创建了配置文件/etc/docker/daemon.json，但此文件为空。　　空：文件内不包含任何字符

解决方案：

　　方案1：不需要修改默认配置的情况下，删除/etc/docker/daemon.json文件。再执行systemctl reset-failed docker.service; systemctl start docker

　　方案2：需要自定义配置的情况下，向/etc/docker/daemon.json文件中写入正常格式的配置内容，再执行systemctl reset-failed docker.service; systemctl start docker