add simple admin server

Author: maxdml

dbos/admin-server.go

@@ -0,0 +1,59 @@
+package dbos
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+type AdminServer struct {
+	server *http.Server
+}
+
+func NewAdminServer() *AdminServer {
+	mux := http.NewServeMux()
+	
+	// Health endpoint
+	mux.HandleFunc("/dbos-healthz", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte(`{"status":"healthy"}`))
+	})
+
+	server := &http.Server{
+		Addr:    ":3001",
+		Handler: mux,
+	}
+
+	return &AdminServer{
+		server: server,
+	}
+}
+
+func (as *AdminServer) Start() error {
+	getLogger().Info("Starting admin server", "port", 3001)
+	
+	go func() {
+		if err := as.server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			getLogger().Error("Admin server error", "error", err)
+		}
+	}()
+	
+	return nil
+}
+
+func (as *AdminServer) Shutdown() error {
+	getLogger().Info("Shutting down admin server")
+	
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	
+	if err := as.server.Shutdown(ctx); err != nil {
+		getLogger().Error("Admin server shutdown error", "error", err)
+		return fmt.Errorf("failed to shutdown admin server: %w", err)
+	}
+	
+	getLogger().Info("Admin server shutdown complete")
+	return nil
+}

dbos/dbos.go

@@ -88,7 +88,8 @@ func getLogger() *slog.Logger {
 }
 
 type config struct {
-	logger *slog.Logger
+	logger      *slog.Logger
+	adminServer *AdminServer
 }
 
 type LaunchOption func(*config)
@@ -99,6 +100,16 @@ func WithLogger(logger *slog.Logger) LaunchOption {
 	}
 }
 
+func WithAdminServer() LaunchOption {
+	return func(config *config) {
+		if config.adminServer == nil {
+			config.adminServer = NewAdminServer()
+		} else {
+			getLogger().Warn("Admin server already initialized, ignoring duplicate call")
+		}
+	}
+}
+
 func Launch(options ...LaunchOption) error {
 	if dbos != nil {
 		fmt.Println("warning: DBOS instance already initialized, skipping re-initialization")