Second checkpoint

internal/cli/worker.go

@@ -0,0 +1,53 @@
+package cli
+
+import (
+	"context"
+	"errors"
+
+	"gis/internal/app"
+	"gis/internal/messaging/rabbitmq"
+
+	"github.com/spf13/cobra"
+	"golang.org/x/sync/errgroup"
+)
+
+var publishExample bool
+
+var workerCmd = &cobra.Command{
+	Use:   "worker",
+	Short: "Run the RabbitMQ consumers (dataset parsing + example)",
+	RunE: func(cmd *cobra.Command, args []string) error {
+		ctx, cancel := signalContext()
+		defer cancel()
+
+		application, err := app.New(ctx)
+		if err != nil {
+			return err
+		}
+		defer application.Close()
+
+		if publishExample {
+			if err := rabbitmq.PublishExample(ctx, application.Publisher()); err != nil {
+				return err
+			}
+			application.Log.Info("published example message")
+		}
+
+		// Run every consumer concurrently; cancel all if one fails.
+		g, gctx := errgroup.WithContext(ctx)
+		for _, c := range application.Consumers() {
+			c := c
+			g.Go(func() error { return c.Run(gctx) })
+		}
+
+		// Graceful shutdown (context cancelled) is not an error.
+		if err := g.Wait(); err != nil && !errors.Is(err, context.Canceled) {
+			return err
+		}
+		return nil
+	},
+}
+
+func init() {
+	workerCmd.Flags().BoolVar(&publishExample, "publish-example", false, "publish one example message before consuming")
+}