Could not edit systemd service file - linux

Question

Need to edit following entries:
[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
in /lib/systemd/system/docker.service file
$ sudo -E systemctl edit docker.service
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd -H fd:// -H tcp://0.0.0.0:2376 --containerd=/run/containerd/containerd.sock
did not update the service file after restart(sudo systemctl restart docker.service)
Edit
On AWS EC2, below is the issue:
$ nano /etc/systemd/system/docker.service.d/override.conf
$ sudo systemctl daemon-reload
$ sudo systemctl restart docker
/lib/systemd/system/docker.service still shows unmodified
1) What is the recommended approach to edit service file(docker.service)?
2) Why /lib/systemd/system/docker.service cannot be edited directly?

Answer 1

You need to create a systemd drop-in file for docker.service.
Create /etc/systemd/system/docker.service.d/override.conf file with contents
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd -H fd:// -H tcp://0.0.0.0:2376 --containerd=/run/containerd/containerd.sock
Reload systemd unit files.
systemctl daemon-reload
NOTE: Reloading systemctl daemon is required after editing any systemd unit file that's as per systemd design. For more info check this.
Restart docker daemon.
systemctl restart docker
You need to restart docker daemon to pick up the latest updated systemd unit file.
For more info check this.