Overview

A note on how to use net/http/pprof with routers other than DefaultServeMux (Go's standard router).

Pitfalls

Simply using a blank import for pprof is not enough.

package main

import (
    _ "net/http/pprof"
)

When using a router other than DefaultServeMux, simply using a blank import will not enable pprof.

Refer to net/http/pprof, which states:

If you are not using DefaultServeMux, you will have to register handlers with the mux you are using.

Solution

Below is an example using my custom router bmf-san/goblin.

package main

import (
    "net/http/pprof"
)

func main() {
        r.Methods(http.MethodGet).Handler("/debug/pprof/", http.HandlerFunc(pprof.Index))
	r.Methods(http.MethodGet).Handler("/debug/pprof/cmdline", http.HandlerFunc(pprof.Cmdline))
	r.Methods(http.MethodGet).Handler("/debug/pprof/profile", http.HandlerFunc(pprof.Profile))
	r.Methods(http.MethodGet).Handler("/debug/pprof/symbol", http.HandlerFunc(pprof.Symbol))
	r.Methods(http.MethodGet).Handler("/debug/pprof/trace", http.HandlerFunc(pprof.Trace))
	r.Methods(http.MethodGet).Handler("/debug/pprof/goroutine", pprof.Handler("goroutine"))
	r.Methods(http.MethodGet).Handler("/debug/pprof/heap", pprof.Handler("heap"))
        r.Methods(http.MethodGet).Handler("/debug/pprof/mutex", pprof.Handler("mutex"))
	r.Methods(http.MethodGet).Handler("/debug/pprof/threadcreate", pprof.Handler("threadcreate"))
	r.Methods(http.MethodGet).Handler("/debug/pprof/block", pprof.Handler("block"))
}

As shown above, you need to set up the routing yourself and configure the pprof Handlers.

For httprouter, the following issue might be helpful: pprof issue with httprouter #236

Side Note

I encountered this issue when trying to set up Go profiling in Pull mode with pyroscope.