Systemd – How to Restart All Instances of an Instantiated Service at Once

systemd

I use the nice feature of systemd: Instantiated Services.

Is there a simple way to reload all instantiated services with one call?

Example: I don't want to run all like this:

systemctl restart autossh@foo
systemctl restart autossh@bar
systemctl restart autossh@blu

I tried this, but this does not work

systemctl restart autossh@*

Update

First I was fascinated by Instantiated Services, but later I realized that running a configuration management tool like Ansible makes more sense. I learned: Keep the tools simple. Many tools starts to implement condition-checking (if .. else …) and loops. For example webservers or mailserver congfiguration. But this should be solved at a different (upper) level: configuration management. See: https://github.com/guettli/programming-guidelines#dont-use-systemd-instantiated-units

Best Answer

Systemd (starting from systemd-209) supports wildcards, however your shell is likely trying to expand them. Use quotes to pass wildcards to the systemctl/service command verbatim:

systemctl restart 'autossh@*'

Related Solutions

Systemd – How to Set Environment Variable in Service

Times change and so do best practices.

The current best way to do this is to run systemctl edit myservice, which will create an override file for you or let you edit an existing one.

In normal installations this will create a directory /etc/systemd/system/myservice.service.d, and inside that directory create a file whose name ends in .conf (typically, override.conf), and in this file you can add to or override any part of the unit shipped by the distribution.

For instance, in a file /etc/systemd/system/myservice.service.d/myenv.conf:

[Service]
Environment="SECRET=pGNqduRFkB4K9C2vijOmUDa2kPtUhArN"
Environment="ANOTHER_SECRET=JP8YLOc2bsNlrGuD6LVTq7L36obpjzxd"

Also note that if the directory exists and is empty, your service will be disabled! If you don't intend to put something in the directory, ensure that it does not exist.

For reference, the old way was:

The recommended way to do this is to create a file /etc/sysconfig/myservice which contains your variables, and then load them with EnvironmentFile.

For complete details, see Fedora's documentation on how to write a systemd script.

Find the location of a systemd unit file service

For units that are defined in actual, static files, this can be seen in systemctl status:

$ systemctl status halt-local.service
● halt-local.service - /usr/sbin/halt.local Compatibility
   Loaded: loaded (/lib/systemd/system/halt-local.service; static)
   Active: inactive (dead)

But there are units that are not defined by files, e.g. with systemd-cron installed. These have no useful location listed with status:

$ systemctl status cron-jojo-0.timer
● cron-jojo-0.timer - [Cron] "*/10 * * * * ..."
   Loaded: loaded (/var/spool/cron/crontabs/jojo)
   Active: active (waiting) since Mon 2015-05-18 14:53:01 UTC; 9min ago

In either case, though, the FragmentPath field is educating:

$ systemctl show -p FragmentPath cron-daily.service
FragmentPath=/lib/systemd/system/cron-daily.service
$ systemctl show -p FragmentPath cron-jojo-0.service
FragmentPath=/run/systemd/generator/cron-jojo-0.service
$ systemctl show -p FragmentPath halt-local.service
FragmentPath=/lib/systemd/system/halt-local.service

Update

Best Answer

Related Solutions

Systemd – How to Set Environment Variable in Service

Find the location of a systemd unit file service

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