[systemd-devel] Temporarily stopping a service while oneshot is running

[Kai Krakow]

Am Thu, 30 Mar 2017 16:13:25 +0200
schrieb Lennart Poettering <lennart at poettering.net>:

> On Tue, 21.03.17 07:47, Ian Pilcher (arequipeno at gmail.com) wrote:
> 
> > I have a oneshot service (run from a timer) that updates the TLS
> > certificates in my mod_nss database.  Because NSS doesn't support
> > concurrent access to the database, I need to temporarily shut down
> > Apache while the certificate update service is running.
> > 
> > Currently, I'm using the following entries in my .service file to
> > accomplish this:
> > 
> >   [Unit]
> >   Description=Update TLS certificates in mod_nss database
> >   # Restart Apache, even if this service fails for some reason
> >   OnFailure=httpd.service
> > 
> >   [Service]
> >   Type=oneshot
> >   # Shut down Apache to avoid concurrent access to the mod_nss
> > database ExecStartPre=/usr/bin/systemctl stop httpd.service
> >   ExecStart=/usr/local/bin/update-nss-certs
> >   ExecStartPost=/usr/bin/systemctl start httpd.service
> > 
> > Is this the best way to do this?  (I can't escape the feeling that
> > there ought to be a more idiomatic way of accomplishing this.)  
> 
> Yes, this appears to be the best, and simplest way to do this to me.

Isn't there a chance that this introduces races when triggered while a
bigger transaction is being executed by systemd? It always feels wrong
to trigger actions that may affect the transaction that is currently
being executed...

-- 
Regards,
Kai

Replies to list-only preferred.