[pve-devel] [RFC common 2/2] REST environment: fork worker: install custom __WARN__ handler

[Thomas Lamprecht]

Am 05/02/2024 um 13:28 schrieb Fiona Ebner:
> So all warnings will be treated consistently inside a worker task. In
> particular, all warnings will count towards the task warning count and
> be more visible in the UI. Avoids the need to switch existing warnings
> to log_warn().
> 
> When pvedaemon forked a worker, the worker would inherit its __WARN__
> handler and also log any warnings to syslog, so make sure those
> warnings are not less visible than before, by also logging to syslog.
> 
> The same warning would not show up in syslog when the task was invoked
> via the CLI instead, which was another inconsistency.
> 
> The __WARN__ handler needs to increment the warning_count for warnings
> issued with Perl's warn. But then in RESTEnvironment.pm's warn method,
> warning_count cannot be incremented anymore, because otherwise a call
> to log_warn() would increment it once, call warn, and then the
> __WARN__ handler would increment it again. The variable is only ever
> read in fork_worker(), so it is safe to just move the code
> incrementing it to the __WARN__ handler, because that will be called
> by both, Perl's warn and log_warn().
> 
> This effectively makes log_warn() and RESTEnvironment.pm's warn method
> not worth using anymore, so deprecate them.
> 

they where deliberately added though, warn and task-log warnings can
be two very different things, which IMO should stay that way..