[CON-243] - Use prometheus middleware package to track route duration

[vicky-g]

Description

The PR is to add duration metric tracking for all routes on Content Node. With this pr, metrics will be added to /prometheus_metrics, and durations and response status codes will be tracked.

Tests

• checked /prometheus_metrics to ensure that the routes are tracked

Example of snippet:

# HELP audius_cn_http_request_duration_seconds duration histogram of http responses labeled with: status_code, audius_cn_http_request_duration_seconds_bucket{le="0.2",status_code="200",method="GET",path="/health_check"} 22
audius_cn_http_request_duration_seconds_bucket{le="0.5",status_code="200",method="GET",path="/health_check"} 22
audius_cn_http_request_duration_seconds_bucket{le="1",status_code="200",method="GET",path="/health_check"} 22
audius_cn_http_request_duration_seconds_bucket{le="4",status_code="200",method="GET",path="/health_check"} 22
audius_cn_http_request_duration_seconds_bucket{le="15",status_code="200",method="GET",path="/health_check"} 22
audius_cn_http_request_duration_seconds_bucket{le="60",status_code="200",method="GET",path="/health_check"} 22
audius_cn_http_request_duration_seconds_bucket{le="+Inf",status_code="200",method="GET",path="/health_check"} 22
audius_cn_http_request_duration_seconds_sum{status_code="200",method="GET",path="/health_check"} 1.053093925
audius_cn_http_request_duration_seconds_count{status_code="200",method="GET",path="/health_check"} 22

• randomly sampled routes to make sure durations + status code responses were tracked by hitting random post/get requests

Monitoring - How will this change be monitored? Are there sufficient logs / alerts?

• check /prometheus_metrics for the api routes to be tracked (will include the key http_request_duration_seconds)
• check DurationTracking logs in logs

[theoilie]

looks great! solid tests and screenshot. only a small nit, no blockers from me

[dmanjunath]

Looks great!

[SidSethi]

😍 love this, the path normalization is clutch

thanks for making the package work and including example in PR desc - just a couple doc requests

[SidSethi]

oh just realized - we prob want to remove the UP gauge since it doesn't have namespace prefix and will conflict with same metric from other nodes
could fix it but prob not worth effort rn vs just setting includeUp = false - either way, nbd your call

[SidSethi]

looks great!! few small things - can address and merge