Distributors ponder a systemd change

Posted Jun 9, 2016 0:54 UTC (Thu) by anselm (subscriber, #2796)
In reply to: Distributors ponder a systemd change by pbonzini
Parent article: Distributors ponder a systemd change

Daemons, by definition, have no business running in user sessions. SIGHUP is used to prod daemons to reread their configuration exactly because they don't have a controlling terminal and are therefore immune against the original use of SIGHUP, namely their session going away – this means that, for a daemon, the signal is available to be used for this.

Distributors ponder a systemd change

Posted Jun 9, 2016 10:04 UTC (Thu) by pbonzini (subscriber, #60935) [Link] (3 responses)

Then why does gpg-agent reread the configuration file if it receives SIGHUP? And that's just the first manpage I opened...

Distributors ponder a systemd change

Posted Jun 9, 2016 11:21 UTC (Thu) by HenrikH (subscriber, #31152) [Link] (2 responses)

Because gpg-agent is a daemon although it's invoked by the user and not by init.

Distributors ponder a systemd change

Posted Jun 9, 2016 11:24 UTC (Thu) by pbonzini (subscriber, #60935) [Link] (1 responses)

Hence the parent assertion that "Daemons, by definition, have no business running in user sessions" is wrong.

Distributors ponder a systemd change

Posted Jun 9, 2016 19:52 UTC (Thu) by HenrikH (subscriber, #31152) [Link]

Well there can always be exceptions to a rule, the most dangerous words are "always" and "never" :-). However something like ssh-agent should be a prime candidate for the systemd socket activation feature, however that might create problems on a multi-user system (I don't know since I have not looked at ssh-agent at all).