Comment by shawnz

1 year ago

I think you actually probably want type=oneshot (and also RemainAfterExit=yes) for the kind of service you're describing

12 comments

shawnz

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brirec  1 year ago

This was ultimately what I needed to do when I wrote a systemd service that managed some firewall rules. It really was a footgun though, what with having essentially different meanings/purposes for ExecStop whether you’re doing a Type=forking, a Type=oneshot, or a Type=oneshot with RemainAfterExit=yes.

And relatedly, I honestly have no idea when I’d want to use ExecStartPre, or multiple ExecStarts, or ExecStartPost, and so on.

  • ww520  1 year ago

    Having different semantics with different proprieties on the same command is really confusing.

    • shawnz  1 year ago

      I would argue the semantics of ExecStop are always the same. It's the command that's executed to stop the service. On the other hand, what it means for a service to be "running" or "stopping" naturally depends on what type of service it is (i.e., is it a daemon or not?)

      6 replies →

    • yencabulator  1 year ago

      Think of it as an enum, Type branches the logic.

          enum Service {
        Exec { ExecStart: String, ... }
        Forking { ExecStart: String, ... }
        OneShot { ExecStart: String, ... }
    }

      You can argue that sometimes that ExecStart could be a different term, but it'd still end up being the same across multiple enum variants.

      1 reply →

  • BenjiWiebe  1 year ago

    It's been enlightening to me to read through some of the distro-provided .service files to see what can be done, with services I'm more of less familiar with.