prometheus_exporter currently reads the controller and action label from action_dispatch.request.parameters. This can lead to conflicts, where there's a form parameter called "action", or "controller" which takes precedence over "which controller action is this?".
This can be validated with a curl request to a rails application instrumented with prometheus_exporter:
# HELP http_requests_total Total HTTP requests from web app.
# TYPE http_requests_total counter
http_requests_total{action="other",controller="test",status="404"} 1
This commit pulls the controller instance from action_controller.instance, and then calls the controller_name / action_name methods, which should be accurate even when conflicting form parameters are provided.
I haven't added any new tests for this, but I have tested it locally (by pointing a local rails app at a local copy of the gem, and doing the curl request above). Please let me know if you'd like a test (I might need a hint as to where to put it though).
prometheus_exporter currently reads the controller and action label from action_dispatch.request.parameters. This can lead to conflicts, where there's a form parameter called "action", or "controller" which takes precedence over "which controller action is this?".
This can be validated with a curl request to a rails application instrumented with prometheus_exporter:
Results in:
This commit pulls the controller instance from
action_controller.instance, and then calls the controller_name / action_name methods, which should be accurate even when conflicting form parameters are provided.I haven't added any new tests for this, but I have tested it locally (by pointing a local rails app at a local copy of the gem, and doing the curl request above). Please let me know if you'd like a test (I might need a hint as to where to put it though).