Add an ability to set tags from logger metadata

[icehaunter]

I believe Sentry.LoggerHandler would benefit from the option to set Sentry tags based on the log metadata as opposed to using it only as extra context.

We have a multi-tenant application, where there is a supervision sub-tree per tenant. Each process already correctly tracks their belonging to a tenant using Logger.metadata calls, and this tenant ID would be extremely useful to have as a Sentry tag for filtering and grouping. I understand the option of using set_tags_context/1, but I would rather avoid code duplication given we already set that metadata field, and LoggerHandler already reads those metadata keys correctly.

I think allowing something like tags: metadata_keys() option would be enough to cover this use-case.

Thanks a lot!

[solnic]

Thanks for the suggestion. I think it's a good idea. There's often quite an overlap in what we set as metadata and what we want as Sentry tags and/or context.

I think allowing something like tags: metadata_keys() option would be enough to cover this use-case.

How would this work exactly?

[whatyouhide]

Yes I agree this is a good idea in general, but I’m also unclear about the exact API.

[ruslandoga]

I think the suggestion here is:

config :sentry, logger_metadata_tags: [:tenant]

Logger.metadata(tenant: 123)
# tags any subsequent event with tenant=123

[icehaunter]

Sorry for a delayed reply. I was thinking this should be an option for the LoggerHandler, akin to the metadata option. So something along the lines of:

config :my_app, :logger, [
  {:handler, :my_sentry_handler, Sentry.LoggerHandler, %{
    config: %{
      metadata: [:file, :line], # these are added to `extra` context
      tags_from_metadata: [:tenant_id] # these are added to `tags` context
    }
  }}
]

with tags_from_metadata maybe being just tags and added to the docs under https://hexdocs.pm/sentry/Sentry.LoggerHandler.html#module-configuration.

[icehaunter]

I've opened a PR for this change so that we can discuss this more materially: #840