OpenTelemetryMetrics should record matched route pattern only, rather than raw path

[DCjanus]

For now, OpenTelemetryMetrics record request uri as metric label, which may cause serious problem, like OOM, in those case

1. random path scan
2. param in paths, like /users/:id

Which means, we should record matched route pattern only, in above cases, prometheus should record label /users/:id only, and ignore NotFound responses,

[DCjanus]

Unfortunately, for now, structure of Route may hard to impl this feature, I'm not sure how to resolve this issue.

[sunli829]

It's a very good proposal, and it's totally achievable, I'll add it later.

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days.

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days.

[Christoph-AK]

I think this is still worth implementing.

[DCjanus]

To achieve this goal, we have to re-design Route module, is there anyone would like to handle this, or post some web-framework-route module design to help us.

[sunli829]

I'll start working on this later.

[sunli829]

I added a path_pattern label to OpenTelemetryMetrics middleware in master branch, please help me test it.

[DCjanus]

is there any exmaple for path_pattern？I'm not sure how to use it

[sunli829]

You don't need to do anything, I've added the http.path_pattern label to the logs in the OpenTelemetryMetrics middleware.

poem/poem/src/middleware/opentelemetry_metrics.rs

Line 80 in a7803d7

if let Some(path_pattern) = req.data::<PathPattern>() {