soroban-rpc: Add admin endpoint including pprof debug endpoints

cmd/soroban-rpc/internal/daemon/daemon.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"net/http"
+	_ "net/http/pprof"
 	"os"
 	"os/signal"
 	"syscall"
@@ -192,7 +193,7 @@ func MustNew(cfg config.LocalConfig) *Daemon {
 	}
 }
 
-func Run(cfg config.LocalConfig, endpoint string) {
+func Run(cfg config.LocalConfig, endpoint string, adminEndpoint string) {
 	d := MustNew(cfg)
 
 	server := &http.Server{
@@ -209,6 +210,16 @@ func Run(cfg config.LocalConfig, endpoint string) {
 			d.logger.Fatalf("Soroban JSON RPC server encountered fatal error: %v", err)
 		}
 	}()
+	var adminServer *http.Server
+	if adminEndpoint != "" {
+		// after importing net/http/pprof, debug endpoints are implicitly registered in the default serve mux
+		adminServer = &http.Server{Addr: adminEndpoint, Handler: http.DefaultServeMux}
+		go func() {
+			if err := adminServer.ListenAndServe(); !errors.Is(err, http.ErrServerClosed) {
+				d.logger.Errorf("Soroban admin server encountered fatal error: %v", err)
+			}
+		}()
+	}
 
 	// Shutdown gracefully when we receive an interrupt signal.
 	// First server.Shutdown closes all open listeners, then closes all idle connections.
@@ -226,4 +237,11 @@ func Run(cfg config.LocalConfig, endpoint string) {
 		d.logger.Errorf("Error during Soroban JSON RPC server Shutdown: %v", err)
 	}
 	d.Close()
+
+	if adminServer != nil {
+		if err := adminServer.Shutdown(shutdownCtx); err != nil {
+			// Error from closing listeners, or context timeout:
+			d.logger.Errorf("Error during Soroban JSON admin server Shutdown: %v", err)
+		}
+	}
 }

cmd/soroban-rpc/main.go

@@ -34,7 +34,7 @@ func mustPositiveUint32(co *config.ConfigOption) error {
 }
 
 func main() {
-	var endpoint string
+	var endpoint, adminEndpoint string
 	var captiveCoreHTTPPort, ingestionTimeoutMinutes, coreTimeoutSeconds, maxHealthyLedgerLatencySeconds uint
 	var serviceConfig localConfig.LocalConfig
 
@@ -47,6 +47,14 @@ func main() {
 			FlagDefault: "localhost:8000",
 			Required:    false,
 		},
+		{
+			Name:        "admin-endpoint",
+			Usage:       "Admin endpoint to listen and serve on. WARNING: this should not be accessible from the Internet and does not use TLS. \"\" (default) disables the admin server",
+			OptType:     types.String,
+			ConfigKey:   &adminEndpoint,
+			FlagDefault: "",
+			Required:    false,
+		},
 		{
 			Name:        "stellar-core-url",
 			ConfigKey:   &serviceConfig.StellarCoreURL,
@@ -275,7 +283,7 @@ func main() {
 			serviceConfig.IngestionTimeout = time.Duration(ingestionTimeoutMinutes) * time.Minute
 			serviceConfig.CoreRequestTimeout = time.Duration(coreTimeoutSeconds) * time.Second
 			serviceConfig.MaxHealthyLedgerLatency = time.Duration(maxHealthyLedgerLatencySeconds) * time.Second
-			daemon.Run(serviceConfig, endpoint)
+			daemon.Run(serviceConfig, endpoint, adminEndpoint)
 		},
 	}