fix: pprof debug endpoints not working with --web.route-prefix #4698
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When using --web.route-prefix or --web.external-url with a path component, the pprof debug endpoints were not accessible. The handlers were directly passing requests to http.DefaultServeMux without adjusting the URL path to match what the pprof handlers expect. For example, with --web.route-prefix=/prometheus/alertmanager, a request to /prometheus/alertmanager/debug/pprof/ was being forwarded with the full path intact, but http.DefaultServeMux only has handlers registered for paths starting with /debug/pprof/. This fix reconstructs the request path by extracting the subpath parameter from the route and prepending /debug to it, ensuring the path matches what http.DefaultServeMux expects. The fix also preserves trailing slashes which are required by some pprof handlers. Added unit tests to verify pprof endpoints work correctly both with and without route prefix configuration. Co-authored-by: Claude <[email protected]> Signed-off-by: Will Hegedus <[email protected]>
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Co-authored-by: Siavash Safi <[email protected]> Signed-off-by: Will Hegedus <[email protected]>
Signed-off-by: Will Hegedus <[email protected]>
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Updated based on PR comments to conform with existing testing patterns Signed-off-by: Will Hegedus <[email protected]>
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ui/web_test.go
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| router.ServeHTTP(w, req) | ||
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| require.Equal(t, http.StatusOK, w.Code) | ||
| require.NotEqual(t, 0, w.Body.Len()) |
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Suggested change
| require.NotEqual(t, 0, w.Body.Len()) | |
| require.Positive(t, w.Body.Len(), "body should not be empty") |
Alternatively we could replace the checks with https://pkg.go.dev/github.com/stretchr/testify/require#Assertions.HTTPBodyContains
but feel free to skip it.
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But I think HTTPBodyContains might not be suitable here, it is best for custom handlers and not a router.
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Updated in 7317f2d to use require.Contains() for checking the body, since -- as you said -- HTTPBodyContains would've required having access to the handlerFunc to pass to the test case.
Signed-off-by: Will Hegedus <[email protected]>
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LGTM, Thank you for your contribution!
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@SuperQ we can merge this one. |
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When using
--web.route-prefixor--web.external-urlwith a path component, the pprof debug endpoints were not accessible. The handlers were directly passing requests to http.DefaultServeMux without adjusting the URL path to match what the automatic pprof handlers expect.For example, with
--web.route-prefix=/prometheus/alertmanager, a request to/prometheus/alertmanager/debug/pprof/was being forwarded with the full path intact, but http.DefaultServeMux only has handlers registered for paths starting with/debug/pprof/.This fix reconstructs the request path by extracting the subpath parameter from the route and prepending /debug to it, ensuring the path matches what http.DefaultServeMux expects. The fix also preserves trailing slashes, which are required by some pprof handlers.
Added tests to verify pprof endpoints work correctly both with and without route prefix configuration.