Promtail: Add scrape_config to accept unstructured logs via HTTP

[ldb]

Is your feature request related to a problem? Please describe.
At the moment there is a way to send 'unstructured' (in the sense of schemaless) logs to Loki via the STDIN scrape_config in Promtail. Structured logs can be sent to Loki using the loki_push_api scrape_config using HTTP. We propose to add a similar feature that accepts unstructured logs via HTTP similar to the STDIN way. This enables a set of new integrations such as with Vercel Log Drains for sending logs via HTTP.

Describe the solution you'd like
Add a scrape_config to accept generic logs via HTTP.

Describe alternatives you've considered
Other ways of connecting cloud services to Promtail, which usually involve writing custom glue code to accept logs via HTTP only to pipe them into Promtail.

Additional context

[aengusrooneygrafana]

Hi Leo, thanks for submitting this - as discussed, we'll check in with @cyriltovena to get his 👀 on this!