fixed problem, where migrate could not connect to db

Backend/database.go

@@ -8,6 +8,7 @@ import (
 	"log/slog"
 
 	"github.com/golang-migrate/migrate/v4"
+	"github.com/golang-migrate/migrate/v4/database/postgres"
 	_ "github.com/golang-migrate/migrate/v4/database/postgres"
 	_ "github.com/golang-migrate/migrate/v4/source/file"
 	_ "github.com/lib/pq"
@@ -20,19 +21,34 @@ func OpenDatabase() (models.IDatabase, error) {
 	dbPassword := helper.GetEnv("POSTGRES_API_PASS", "password")
 	dbTz := helper.GetEnv("TZ", "Europe/Berlin")
 
-	connStr := fmt.Sprintf("postgres://%s:%s@%s:5432/%s?sslmode=disable&TimeZone=%s", dbUser, dbPassword, dbHost, dbName, dbTz)
+	connStr := fmt.Sprintf(
+		"host=%s user=%s dbname=%s password=%s sslmode=disable TimeZone=%s",
+		dbHost, dbUser, dbName, dbPassword, dbTz)
+
 	return sql.Open("postgres", connStr)
 }
 
 func Migrate() error {
 	dbHost := helper.GetEnv("POSTGRES_HOST", "localhost")
 	dbName := helper.GetEnv("POSTGRES_DB", "arbeitszeitmessung")
-	// dbUser := helper.GetEnv("POSTGRES_USER", "api_nutzer")
 	dbPassword := helper.GetEnv("POSTGRES_PASSWORD", "password")
 	dbTz := helper.GetEnv("TZ", "Europe/Berlin")
 
-	connStr := fmt.Sprintf("postgres://migrate:%s@%s:5432/%s?sslmode=disable&TimeZone=%s", dbPassword, dbHost, dbName, dbTz)
-	m, err := migrate.New("file:///migrations", connStr)
+	connStr := fmt.Sprintf(
+		"host=%s user=%s dbname=%s password=%s sslmode=disable TimeZone=%s",
+		dbHost, "migrate", dbName, dbPassword, dbTz)
+
+	db, err := sql.Open("postgres", connStr)
+	if err != nil {
+		return err
+	}
+
+	driver, err := postgres.WithInstance(db, &postgres.Config{})
+	if err != nil {
+		return err
+	}
+
+	m, err := migrate.NewWithDatabaseInstance("file:///app/migrations", "postgres", driver)
 	if err != nil {
 		return err
 	}