Improve pprof in api service (#727)

* Disable stripping binary symbols

* use separate port for pprof

Author: ilyaluk

Dockerfile

@@ -9,7 +9,7 @@ RUN --mount=type=cache,target=/root/.cache/go-build go mod download
 
 # Now adding all the code and start building
 ADD . .
-RUN --mount=type=cache,target=/root/.cache/go-build GOOS=linux go build -trimpath -ldflags "-s -X cmd.Version=$VERSION -X main.Version=$VERSION -linkmode external -extldflags '-static'" -v -o mev-boost-relay .
+RUN --mount=type=cache,target=/root/.cache/go-build GOOS=linux go build -trimpath -ldflags "-X cmd.Version=$VERSION -X main.Version=$VERSION" -v -o mev-boost-relay .
 
 FROM alpine
 RUN apk add --no-cache libstdc++ libc6-compat

cmd/api.go

@@ -24,24 +24,24 @@ var (
 	apiDefaultSecretKey  = common.GetEnv("SECRET_KEY", "")
 	apiDefaultLogTag     = os.Getenv("LOG_TAG")
 
-	apiDefaultPprofEnabled       = os.Getenv("PPROF") == "1"
+	apiDefaultPprofListenAddr    = os.Getenv("PPROF_ADDR")
 	apiDefaultInternalAPIEnabled = os.Getenv("ENABLE_INTERNAL_API") == "1"
 
 	// Default Builder, Data, and Proposer API as true.
 	apiDefaultBuilderAPIEnabled  = os.Getenv("DISABLE_BUILDER_API") != "1"
 	apiDefaultDataAPIEnabled     = os.Getenv("DISABLE_DATA_API") != "1"
 	apiDefaultProposerAPIEnabled = os.Getenv("DISABLE_PROPOSER_API") != "1"
 
-	apiListenAddr   string
-	apiPprofEnabled bool
-	apiSecretKey    string
-	apiBlockSimURL  string
-	apiDebug        bool
-	apiBuilderAPI   bool
-	apiDataAPI      bool
-	apiInternalAPI  bool
-	apiProposerAPI  bool
-	apiLogTag       string
+	apiListenAddr      string
+	apiPprofListenAddr string
+	apiSecretKey       string
+	apiBlockSimURL     string
+	apiDebug           bool
+	apiBuilderAPI      bool
+	apiDataAPI         bool
+	apiInternalAPI     bool
+	apiProposerAPI     bool
+	apiLogTag          string
 )
 
 func init() {
@@ -63,7 +63,8 @@ func init() {
 	apiCmd.Flags().StringVar(&apiBlockSimURL, "blocksim", apiDefaultBlockSim, "URL for block simulator")
 	apiCmd.Flags().StringVar(&network, "network", defaultNetwork, "Which network to use")
 
-	apiCmd.Flags().BoolVar(&apiPprofEnabled, "pprof", apiDefaultPprofEnabled, "enable pprof API")
+	apiCmd.Flags().StringVar(&apiPprofListenAddr, "pprof-listen-addr", apiDefaultPprofListenAddr, "listen address for pprof, empty to disable")
+
 	apiCmd.Flags().BoolVar(&apiBuilderAPI, "builder-api", apiDefaultBuilderAPIEnabled, "enable builder API (/builder/...)")
 	apiCmd.Flags().BoolVar(&apiDataAPI, "data-api", apiDefaultDataAPIEnabled, "enable data API (/data/...)")
 	apiCmd.Flags().BoolVar(&apiInternalAPI, "internal-api", apiDefaultInternalAPIEnabled, "enable internal API (/internal/...)")
@@ -165,11 +166,12 @@ var apiCmd = &cobra.Command{
 			EthNetDetails: *networkInfo,
 			BlockSimURL:   apiBlockSimURL,
 
+			PprofListenAddr: apiPprofListenAddr,
+
 			BlockBuilderAPI: apiBuilderAPI,
 			DataAPI:         apiDataAPI,
 			InternalAPI:     apiInternalAPI,
 			ProposerAPI:     apiProposerAPI,
-			PprofAPI:        apiPprofEnabled,
 		}
 
 		// Decode the private key

services/api/service.go

@@ -143,11 +143,12 @@ type RelayAPIOpts struct {
 	// Network specific variables
 	EthNetDetails common.EthNetworkDetails
 
+	PprofListenAddr string
+
 	// APIs to enable
 	ProposerAPI     bool
 	BlockBuilderAPI bool
 	DataAPI         bool
-	PprofAPI        bool
 	InternalAPI     bool
 }
 
@@ -383,12 +384,6 @@ func (api *RelayAPI) getRouter() http.Handler {
 		r.HandleFunc(pathDataValidatorRegistration, api.handleDataValidatorRegistration).Methods(http.MethodGet)
 	}
 
-	// Pprof
-	if api.opts.PprofAPI {
-		api.log.Info("pprof API enabled")
-		r.PathPrefix("/debug/pprof/").Handler(http.DefaultServeMux)
-	}
-
 	// /internal/...
 	if api.opts.InternalAPI {
 		api.log.Info("internal API enabled")
@@ -516,6 +511,17 @@ func (api *RelayAPI) StartServer() (err error) {
 		}
 	}()
 
+	if api.opts.PprofListenAddr != "" {
+		api.log.Info("pprof API is listening on", api.opts.PprofListenAddr)
+		go func() {
+			//nolint:gosec // we should not expose pprof externally anyway
+			err := http.ListenAndServe(api.opts.PprofListenAddr, http.DefaultServeMux)
+			if err != nil && !errors.Is(err, http.ErrServerClosed) {
+				api.log.WithError(err).Fatal("failed to start pprof API")
+			}
+		}()
+	}
+
 	// create and start HTTP server
 	api.srv = &http.Server{
 		Addr:    api.opts.ListenAddr,