[systemd-devel] Antw: [EXT] Re: Starting a socket unit that finds an active service fails

[Ulrich Windl]

>>> Lennart Poettering <lennart at poettering.net> schrieb am 29.01.2021 um 16:38
in
Nachricht <20210129153859.GA31189 at gardel-login>:
> On Fr, 29.01.21 12:30, Ulrich Windl (Ulrich.Windl at rz.uni-regensburg.de) 
> wrote:
> 
>> Hi!
>>
>> I wonder whether this is a bug:
>> When starting a socket unit that finds ist service active already, I get an

> error
>> systemd[1]: libvirtd-tls.socket: Socket service libvirtd.service already 
> active, refusing.
>> systemd[1]: Failed to listen on Libvirt TLS IP socket.
>>
>> When using systemd units in a pacemaker cluster this is fatal:
>> pacemaker-controld[7467]:  notice: Transition 316 action 81 
> (prm_libvirtd-tls-sock_start_0 on rksaph19): expected 'ok' but got 'error'
>>
>> Maybe the special problem is that two socket units (libvirtd-ro.socket, 
> libvirtd-tls.socket) exist to start the same service (libvirtd.service).
>>
>> I'm clueless how to handle that. Ideas?
> 
> The socket activation logic works so that the activation sockets are
> passed to the service being activated during execve(). Thus, if a
> service is already running we can't pass in more sockets: you have to
> restart the service so that there's another execve() we can pass the
> newly started sockets over.
> 
> My guess is that your service — if it finds that it didn't get a
> socket passed in that it needs — just creates the socket itself as a
> fallback...
> 
> It's generally a good idea for services to have Requires= + After= on
> the sockets that actviate it, to make sure that the sockets are always
> started before the service itself, and the situation you are seeing
> cannot happen.

I think before running things from pacemaker,I started them in this order
libvirtd
libvirtd-ro
libvirtd-tls

And there was no problem (or I missed something).
Now with pacemaker I assumed that either libvirtd-ro or libvirtd-tls would
start libvirtd as needed with no explicit start of libvirtd.

Regards,
Ulrich


> 
> Lennart
> 
> --
> Lennart Poettering, Berlin