Systemd – automatically start/restart specific systemd service after another service is started/restarted

You can analyze systemd boot sequence by following command. View the output file by using a SVG supporting web browser.

systemd-analyze plot > test.svg

That plotting will provide you last boot's timing statistics, which will provide you more clarified point of view to problem.

I solved my NFS mounting problem by adding mount commands in to /etc/rc.local. However I'm not sure, will it work with glusterd integration, worth a try for a quick fix. In order to make systemd run rc.local you should satisfy following condition:

# grep Condition /usr/lib/systemd/system/rc-local.service
ConditionFileIsExecutable=/etc/rc.d/rc.local

Well, assuming that the only thing changing per unit file is the remote.example.com part, you can use an Instantiated Service.

From the systemd.unit man page:

Optionally, units may be instantiated from a template file at runtime. This allows creation of multiple units from a single configuration file. If systemd looks for a unit configuration file, it will first search for the literal unit name in the file system. If that yields no success and the unit name contains an "@" character, systemd will look for a unit template that shares the same name but with the instance string (i.e. the part between the "@" character and the suffix) removed. Example: if a service getty@tty3.service is requested and no file by that name is found, systemd will look for getty@.service and instantiate a service from that configuration file if it is found.

Basically, you create a single unit file, which contains a variable (usually %i) where the differences occur and then they get linked when you "enable" that service.

For example, I have a unit file called /etc/systemd/system/autossh@.service that looks like this:

[Unit]
Description=AutoSSH service for ServiceABC on %i
After=network.target

[Service]
Environment=AUTOSSH_GATETIME=30 AUTOSSH_LOGFILE=/var/log/autossh/%i.log AUTOSSH_PIDFILE=/var/run/autossh.%i.pid
PIDFile=/var/run/autossh.%i.pid
#Type=forking
ExecStart=/usr/bin/autossh -M 40000 -NR 5000:127.0.0.1:5000 -i /opt/ServiceABC/.ssh/id_rsa_ServiceABC -l ServiceABC %i

[Install]
WantedBy=multi-user.target

Which I've then enabled

[user@anotherhost ~]$ sudo systemctl enable autossh@somehost.example.com
ln -s '/etc/systemd/system/autossh@.service' '/etc/systemd/system/multi-user.target.wants/autossh@somehost.example.com.service'

And can intereact with

[user@anotherhost ~]$ sudo systemctl start autossh@somehost.example.com
[user@anotherhost ~]$ sudo systemctl status autossh@somehost.example.com
autossh@somehost.example.service - AutoSSH service for ServiceABC on somehost.example
   Loaded: loaded (/etc/systemd/system/autossh@.service; enabled)
   Active: active (running) since Tue 2015-10-20 13:19:01 EDT; 17s ago
 Main PID: 32524 (autossh)
   CGroup: /system.slice/system-autossh.slice/autossh@somehost.example.com.service
           ├─32524 /usr/bin/autossh -M 40000 -NR 5000:127.0.0.1:5000 -i /opt/ServiceABC/.ssh/id_rsa_ServiceABC -l ServiceABC somehost.example.com
           └─32525 /usr/bin/ssh -L 40000:127.0.0.1:40000 -R 40000:127.0.0.1:40001 -NR 5000:127.0.0.1:5000 -i /opt/ServiceABC/.ssh/id_rsa_ServiceABC -l ServiceABC somehost.example.com

Oct 20 13:19:01 anotherhost.example.com systemd[1]: Started AutoSSH service for ServiceABC on somehost.example.com.
[user@anotherhost ~]$ sudo systemctl status autossh@somehost.example.com
[user@anotherhost ~]$ sudo systemctl status autossh@somehost.example.com
autossh@somehost.example.com.service - AutoSSH service for ServiceABC on somehost.example.com
   Loaded: loaded (/etc/systemd/system/autossh@.service; enabled)
   Active: inactive (dead) since Tue 2015-10-20 13:24:10 EDT; 2s ago
  Process: 32524 ExecStart=/usr/bin/autossh -M 40000 -NR 5000:127.0.0.1:5000 -i /opt/ServiceABC/.ssh/id_rsa_ServiceABC -l ServiceABC %i (code=exited, status=0/SUCCESS)
 Main PID: 32524 (code=exited, status=0/SUCCESS)

Oct 20 13:19:01 anotherhost.example.com systemd[1]: Started AutoSSH service for ServiceABC on somehost.example.com.
Oct 20 13:24:10 anotherhost.example.com systemd[1]: Stopping AutoSSH service for ServiceABC on somehost.example.com...
Oct 20 13:24:10 anotherhost.example.com systemd[1]: Stopped AutoSSH service for ServiceABC on somehost.example.com.

As you can see, all instances of %i in the unit file get replaced with somehost.example.com.

There's a bunch more specifiers that you can use in a unit file though, but I find %i to work best in cases like this.