Remove default User-Agent handling in NewHeaderPruningReverseProxy

[kevinmingtarja]

/area networking
/kind cleanup

Ask your question here:

in NewHeaderPruningReverseProxy, we are checking whether the User-Agent is unset. If yes, we explicitly set it to "" so that it's not set to the default Go HTTP client User-Agent:

serving/pkg/http/proxy.go

Lines 50 to 54 in e41df09

	// Copied from httputil.NewSingleHostReverseProxy.
	if _, ok := req.Header[netheader.UserAgentKey]; !ok {
	// explicitly disable User-Agent so it's not set to default value
	req.Header.Set(netheader.UserAgentKey, "")
	}

but i think this is no longer necessary starting from golang/go@f001df5 (>= go1.20rc1), where this check was moved from httputil.NewSingleHostReverseProxy (where the Knative code was copied from, as noted from the comment) to ReverseProxy.ServeHTTP, so all instances of ReverseProxy will now have this behaviour.

so should we remove this conditional block?

[dprotaso]

/triage accepted

Yeah we should drop if the go std lib does it for us

[TusharMohapatra07]

Can i take up this issue ?