feat: add asynq worker skeleton

worker/cmd/worker/main.go

@@ -2,12 +2,21 @@ package main
 
 import (
 	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"log/slog"
 	"os"
 	"os/signal"
 	"syscall"
+	"time"
 
 	"forgejo.digital-droplets.de/philschlo/proxui/platform/config"
 	"forgejo.digital-droplets.de/philschlo/proxui/platform/logging"
+	"github.com/hibiken/asynq"
+	_ "github.com/jackc/pgx/v5/stdlib"
+
+	"proxui/worker/internal/tasks"
 )
 
 func main() {
@@ -19,10 +28,54 @@ func main() {
 	}
 
 	logger := logging.New("worker", cfg.AppEnv, cfg.LogLevel)
+	db, err := openDatabase(cfg.DatabaseURL)
+	if err != nil {
+		logger.Error("failed to connect database", "error", err)
+		os.Exit(1)
+	}
+	defer db.Close()
+
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 	defer stop()
 
-	logger.Info("worker started", "concurrency", cfg.WorkerConcurrency)
+	redis := asynq.RedisClientOpt{Addr: cfg.RedisAddr}
+	server := asynq.NewServer(redis, asynq.Config{
+		Concurrency: cfg.WorkerConcurrency,
+	})
+	mux := asynq.NewServeMux()
+	registerHandlers(mux, logger)
+
+	go func() {
+		logger.Info("worker started", "concurrency", cfg.WorkerConcurrency, "redis_addr", cfg.RedisAddr)
+		if err := server.Run(mux); err != nil && !errors.Is(err, asynq.ErrServerClosed) {
+			logger.Error("worker failed", "error", err)
+			stop()
+		}
+	}()
+
 	<-ctx.Done()
+	server.Shutdown()
 	logger.Info("worker stopped")
 }
+
+func registerHandlers(mux *asynq.ServeMux, logger *slog.Logger) {
+	mux.Handle(tasks.TypeDummy, tasks.NewDummyHandler(logger))
+}
+
+func openDatabase(databaseURL string) (*sql.DB, error) {
+	if databaseURL == "" {
+		return nil, fmt.Errorf("DATABASE_URL is required")
+	}
+
+	db, err := sql.Open("pgx", databaseURL)
+	if err != nil {
+		return nil, err
+	}
+	db.SetConnMaxLifetime(30 * time.Minute)
+	if err := db.Ping(); err != nil {
+		_ = db.Close()
+		return nil, err
+	}
+
+	return db, nil
+}