Consider updating severity levels for MozLog

[ncloudioj]

As more of our services have been migrated to GCP, MozLog's severity levels are causing issues as they're different from those of GCP Cloud Logging. Dockerflow-compliant services need to remap SLs in order for GCL to render log records properly.

Is it time to update MozLog's SLs to match against GCL now?

@jasonthomas @mostlygeek @jbuck WDYT?

[mostlygeek]

@grahamalama is also looking into this, see https://github.com/mozilla-it/ctms-api/issues/771.

I think it's the right time to have this discussion. Many things have changed since the mozlog spec was created.

That said, the severity levels map almost exactly.

MozLog uses syslog severity levels:

these are the GCL ones:

[ncloudioj]

Yep, the severity levels match exactly between the two, we just need to update the level values accordingly so that GCL can consume/render them properly.