profiling: Support binding pprof server to custom network interfaces (#36580)

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

docs/sources/troubleshooting/diagnostics.md

@@ -10,11 +10,11 @@ when investigating certain performance problems. It's _not_ recommended to have
 
 ## Turn on profiling
 
-The `grafana-server` can be started with the arguments `-profile` to enable profiling and `-profile-port` to override
-the default HTTP port (`6060`) where the `pprof` debugging endpoints are available, for example:
+The `grafana-server` can be started with the arguments `-profile` to enable profiling, `-profile-addr` to override the default HTTP address (`localhost`), and
+`-profile-port` to override the default HTTP port (`6060`) where the `pprof` debugging endpoints are available. For example:
 
 ```bash
-./grafana-server -profile -profile-port=8080
+./grafana-server -profile -profile-addr=0.0.0.0 -profile-port=8080
 ```
 
 Note that `pprof` debugging endpoints are served on a different port than the Grafana HTTP server.
@@ -23,6 +23,7 @@ You can configure or override profiling settings using environment variables:
 
 ```bash
 export GF_DIAGNOSTICS_PROFILING_ENABLED=true
+export GF_DIAGNOSTICS_PROFILING_ADDR=0.0.0.0
 export GF_DIAGNOSTICS_PROFILING_PORT=8080
 ```
 
@@ -52,4 +53,4 @@ go tool trace <trace file>
 2019/11/24 22:20:42 Opening browser. Trace viewer is listening on http://127.0.0.1:39735
 ```
 
-See [Go command trace](https://golang.org/cmd/trace/) for more information about how to analyze trace files.
+For more information about how to analyze trace files, refer to [Go command trace](https://golang.org/cmd/trace/).

pkg/cmd/grafana-server/diagnostics.go

@@ -8,6 +8,7 @@ import (
 
 const (
 	profilingEnabledEnvName = "GF_DIAGNOSTICS_PROFILING_ENABLED"
+	profilingAddrEnvName    = "GF_DIAGNOSTICS_PROFILING_ADDR"
 	profilingPortEnvName    = "GF_DIAGNOSTICS_PROFILING_PORT"
 	tracingEnabledEnvName   = "GF_DIAGNOSTICS_TRACING_ENABLED"
 	tracingFileEnvName      = "GF_DIAGNOSTICS_TRACING_FILE"
@@ -15,12 +16,14 @@ const (
 
 type profilingDiagnostics struct {
 	enabled bool
+	addr    string
 	port    uint64
 }
 
-func newProfilingDiagnostics(enabled bool, port uint64) *profilingDiagnostics {
+func newProfilingDiagnostics(enabled bool, addr string, port uint64) *profilingDiagnostics {
 	return &profilingDiagnostics{
 		enabled: enabled,
+		addr:    addr,
 		port:    port,
 	}
 }
@@ -35,6 +38,11 @@ func (pd *profilingDiagnostics) overrideWithEnv() error {
 		pd.enabled = enabled
 	}
 
+	addrEnv := os.Getenv(profilingAddrEnvName)
+	if addrEnv != "" {
+		pd.addr = addrEnv
+	}
+
 	portEnv := os.Getenv(profilingPortEnvName)
 	if portEnv != "" {
 		port, parseErr := strconv.ParseUint(portEnv, 0, 64)

pkg/cmd/grafana-server/diagnostics_test.go

@@ -12,14 +12,15 @@ func TestProfilingDiagnostics(t *testing.T) {
 	tcs := []struct {
 		defaults   *profilingDiagnostics
 		enabledEnv string
+		addrEnv    string
 		portEnv    string
 		expected   *profilingDiagnostics
 	}{
-		{defaults: newProfilingDiagnostics(false, 6060), enabledEnv: "", portEnv: "", expected: newProfilingDiagnostics(false, 6060)},
-		{defaults: newProfilingDiagnostics(true, 8080), enabledEnv: "", portEnv: "", expected: newProfilingDiagnostics(true, 8080)},
-		{defaults: newProfilingDiagnostics(false, 6060), enabledEnv: "false", portEnv: "8080", expected: newProfilingDiagnostics(false, 8080)},
-		{defaults: newProfilingDiagnostics(false, 6060), enabledEnv: "true", portEnv: "8080", expected: newProfilingDiagnostics(true, 8080)},
-		{defaults: newProfilingDiagnostics(false, 6060), enabledEnv: "true", portEnv: "", expected: newProfilingDiagnostics(true, 6060)},
+		{defaults: newProfilingDiagnostics(false, "localhost", 6060), enabledEnv: "", addrEnv: "", portEnv: "", expected: newProfilingDiagnostics(false, "localhost", 6060)},
+		{defaults: newProfilingDiagnostics(true, "0.0.0.0", 8080), enabledEnv: "", addrEnv: "", portEnv: "", expected: newProfilingDiagnostics(true, "0.0.0.0", 8080)},
+		{defaults: newProfilingDiagnostics(false, "", 6060), enabledEnv: "false", addrEnv: "", portEnv: "8080", expected: newProfilingDiagnostics(false, "", 8080)},
+		{defaults: newProfilingDiagnostics(false, "localhost", 6060), enabledEnv: "true", addrEnv: "0.0.0.0", portEnv: "8080", expected: newProfilingDiagnostics(true, "0.0.0.0", 8080)},
+		{defaults: newProfilingDiagnostics(false, "127.0.0.1", 6060), enabledEnv: "true", addrEnv: "", portEnv: "", expected: newProfilingDiagnostics(true, "127.0.0.1", 6060)},
 	}
 
 	for i, tc := range tcs {
@@ -29,6 +30,10 @@ func TestProfilingDiagnostics(t *testing.T) {
 				err := os.Setenv(profilingEnabledEnvName, tc.enabledEnv)
 				assert.NoError(t, err)
 			}
+			if tc.addrEnv != "" {
+				err := os.Setenv(profilingAddrEnvName, tc.addrEnv)
+				assert.NoError(t, err)
+			}
 			if tc.portEnv != "" {
 				err := os.Setenv(profilingPortEnvName, tc.portEnv)
 				assert.NoError(t, err)

pkg/cmd/grafana-server/main.go

@@ -63,6 +63,7 @@ func main() {
 		v           = flag.Bool("v", false, "prints current version and exits")
 		vv          = flag.Bool("vv", false, "prints current version, all dependencies and exits")
 		profile     = flag.Bool("profile", false, "Turn on pprof profiling")
+		profileAddr = flag.String("profile-addr", "localhost", "Define custom address for profiling")
 		profilePort = flag.Uint64("profile-port", 6060, "Define custom port for profiling")
 		tracing     = flag.Bool("tracing", false, "Turn on tracing")
 		tracingFile = flag.String("tracing-file", "trace.out", "Define tracing output file")
@@ -83,7 +84,7 @@ func main() {
 		os.Exit(0)
 	}
 
-	profileDiagnostics := newProfilingDiagnostics(*profile, *profilePort)
+	profileDiagnostics := newProfilingDiagnostics(*profile, *profileAddr, *profilePort)
 	if err := profileDiagnostics.overrideWithEnv(); err != nil {
 		fmt.Fprintln(os.Stderr, err.Error())
 		os.Exit(1)
@@ -96,10 +97,10 @@ func main() {
 	}
 
 	if profileDiagnostics.enabled {
-		fmt.Println("diagnostics: pprof profiling enabled", "port", profileDiagnostics.port)
+		fmt.Println("diagnostics: pprof profiling enabled", "addr", profileDiagnostics.addr, "port", profileDiagnostics.port)
 		runtime.SetBlockProfileRate(1)
 		go func() {
-			err := http.ListenAndServe(fmt.Sprintf("localhost:%d", profileDiagnostics.port), nil)
+			err := http.ListenAndServe(fmt.Sprintf("%s:%d", profileDiagnostics.addr, profileDiagnostics.port), nil)
 			if err != nil {
 				panic(err)
 			}