Widen localhost filter checks to the request headers

[InterstellarStella]

Problem Statement

Currently, we only check an event's IP address and URL to see if it came from localhost, and to decide if it should be dropped through the inbound filter. The relevant code is here. Sometimes, an event might not include this information though, and may include it in the Host and X-Forwarded-Host request headers instead.

Solution Brainstorm

Make sure to check the Host and X-Forwarded-Host request headers as well when determining if an event should be filtered out because it comes from localhost.

Product Area

Processing

[getsantry]

Assigning to @getsentry/support for routing ⏲️

[getsantry]

Routing to @getsentry/product-owners-processing for triage ⏲️

[InterstellarStella]

https://sentry.zendesk.com/agent/tickets/146945

[loewenheim]

Adding this to our triage.