fix(syslog): open syslog channel on write

[leftybournes]

• Resolves: [Bug]: Not possible to use syslog for both normal logs and audit logs with different tags #49831

Summary

This fixes a bug where only one tag gets used when multiple tags have been configured (e.g. different tags for 'syslog_tag' and 'syslog_tag_audit')

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[provokateurin]

I'm not familiar with syslog, but I don't understand how this change affects the tag. All it does is calling openlog() later and on every write, but the tag is only set once and never changed.

[leftybournes]

It's for when apps need their own loggers and are configured to use syslog with a custom tag in addition to core's logger. The admin_audit app instantiates its own Syslog when configured to use it.

[provokateurin]

Ok but when it creates the instance it can pass the tag already and openlog will be called with it, no?

[leftybournes]

Yes, but that's what has been causing the bug in the linked issue. What currently happens is core calls openlog() with its own tag on create and then admin_audit calls it with a different tag on create. All logs get tagged with the value set by admin_audit because it's the last to call openlog(). It's not possible to have two or more simultaneous channels open which is why it's done on write.

[provokateurin]

Ahhh that totally makes sense. Please include such information in the PR description, so the reason why it was broken and how this fixes it is clear from the start.

[leftybournes]

Please include such information in the PR description, so the reason why it was broken and how this fixes it is clear from the start.

My bad 😅

I'll make sure to do that next time.

[leftybournes]

/backport to stable31

[leftybournes]

/backport to stable30