Allow setting (access) log timezone directly

[jnoordsij]

Welcome!

• Yes, I've searched similar issues on GitHub and didn't find any.
• Yes, I've searched similar issues on the Traefik community forum and didn't find any.

What did you expect to see?

Currently, to allow setting a custom timezone for (access) logs, one needs to alter the following chart values (see also https://doc.traefik.io/traefik/observability/access-logs/#time-zones):

1. Pass an additional env parameter TZ=US/Alaska, i.e. in terms of values (see also Allow extending env value more easily #958):

  env:
    - name: POD_NAME
      valueFrom:
        fieldRef:
          fieldPath: metadata.name
    - name: POD_NAMESPACE
      valueFrom:
        fieldRef:
          fieldPath: metadata.namespace
    - name: TZ
      value: US/Alaska

2. Drop the StartUTC field, i.e. in terms of values:

  logs:
    access:
      fields:
        general:
          names:
            # see https://doc.traefik.io/traefik/observability/access-logs/#time-zones
            StartUTC: drop

It would be nice to add a new chart value, e.g. timezone, that would both of these things at once without further changes.

[mloiseleur]

It's not mandatory. One can have StartLocal field without dropping StartUTC.
It's detailed in this blog post on logging.

[jnoordsij]

Ah I see, I only looked at the docs and it wasn't mentioned there, but I understand with json formatting it behaves differently.

Still I think the approach suggested above makes some sense as a "default" convenience option for people, to allow them to easily change timezones without having to fully understand all logging concepts and chart values. Though given that it probably will be used by a limited amount of people, the docs are probably extensive enough at this point (or maybe we can add it here as a little example to the examples doc?).

[mloiseleur]

Sure, why not.
Your PRs are more than welcome :)