add -db flag for persistent data

Makefile

@@ -14,6 +14,10 @@ test-go:
 run-go:
 	SERVE_FROM_FS=true cd desktopcollector; go run ./...
 
+.PHONY: run-go-db
+run-go-db:
+	SERVE_FROM_FS=true cd desktopcollector; go run ./... --db /tmp/otel.db
+
 .PHONY: build-js
 build-js:
 	cd desktopexporter/internal/app; npx esbuild --bundle main.tsx main.css --outdir=../server/static

desktopcollector/go.mod

@@ -20,6 +20,8 @@ require (
 	golang.org/x/sys v0.24.0
 )
 
+replace github.com/CtrlSpice/otel-desktop-viewer/desktopexporter => ../desktopexporter
+
 require (
 	github.com/apache/arrow/go/v17 v17.0.0 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect

desktopexporter/config.go

@@ -8,6 +8,9 @@ import (
 type Config struct {
 	// Endpoint defines the host and port where we serve our frontend app
 	Endpoint string `mapstructure:"endpoint"`
+	// DBFilename defines the local filesystem path for persistent database storage.
+	// If set to "", no data will be stored persistently.
+	DBFilename string
 }
 
 // Validate checks if the exporter configuration is valid

desktopexporter/exporter.go

@@ -20,7 +20,7 @@ type desktopExporter struct {
 }
 
 func newDesktopExporter(cfg *Config) *desktopExporter {
-	server := server.NewServer(cfg.Endpoint)
+	server := server.NewServer(cfg.Endpoint, cfg.DBFilename)
 	return &desktopExporter{
 		server: server,
 	}

desktopexporter/factory.go

@@ -17,20 +17,23 @@ const (
 )
 
 // Creates a factory for the Desktop Exporter
-func NewFactory() exporter.Factory {
+func NewFactory(dbFilename string) exporter.Factory {
 	return exporter.NewFactory(
 		metadata.Type,
-		createDefaultConfig,
+		createDefaultConfig(dbFilename),
 		exporter.WithTraces(createTracesExporter, metadata.TracesStability),
 		exporter.WithMetrics(createMetricsExporter, metadata.MetricsStability),
 		exporter.WithLogs(createLogsExporter, metadata.LogsStability),
 	)
 }
 
 // Create default configurations
-func createDefaultConfig() component.Config {
-	return &Config{
-		Endpoint: defaultEndpoint,
+func createDefaultConfig(dbFilename string) func() component.Config {
+	return func() component.Config {
+		return &Config{
+			Endpoint:   defaultEndpoint,
+			DBFilename: dbFilename,
+		}
 	}
 }
 

desktopexporter/internal/server/server.go

@@ -25,12 +25,12 @@ type Server struct {
 	Store  *store.Store
 }
 
-func NewServer(endpoint string) *Server {
+func NewServer(endpoint, dbFilename string) *Server {
 	s := Server{
 		server: http.Server{
 			Addr: endpoint,
 		},
-		Store: store.NewStore(context.Background()),
+		Store: store.NewStore(context.Background(), dbFilename),
 	}
 
 	serveFromFS, err := strconv.ParseBool(os.Getenv("SERVE_FROM_FS"))

desktopexporter/internal/server/server_test.go

@@ -16,7 +16,7 @@ import (
 )
 
 func setupEmpty() (*httptest.Server, func()) {
-	server := NewServer("localhost:8000")
+	server := NewServer("localhost:8000", "")
 	testServer := httptest.NewServer(server.Handler(false))
 
 	return testServer, func() {
@@ -26,7 +26,7 @@ func setupEmpty() (*httptest.Server, func()) {
 }
 
 func setupWithTrace(t *testing.T) (*httptest.Server, func(*testing.T)) {
-	server := NewServer("localhost:8000")
+	server := NewServer("localhost:8000", "")
 	testSpanData := telemetry.SpanData{
 		TraceID:      "1234567890",
 		TraceState:   "",

desktopexporter/internal/store/store.go

@@ -21,8 +21,8 @@ type Store struct {
 	conn driver.Conn
 }
 
-func NewStore(ctx context.Context) *Store {
-	connector, err := duckdb.NewConnector("", nil)
+func NewStore(ctx context.Context, dbFilename string) *Store {
+	connector, err := duckdb.NewConnector(dbFilename, nil)
 	if err != nil {
 		log.Fatalf("could not initialize new connector: %s", err.Error())
 	}