Don't ignore config flag for yggdrasil demo if set

Signed-off-by: bn4t <me@bn4t.me>

cmd/dendrite-demo-yggdrasil/main.go

@@ -19,8 +19,10 @@ import (
 	"crypto/tls"
 	"flag"
 	"fmt"
+	"github.com/matrix-org/gomatrixserverlib"
 	"net"
 	"net/http"
+	"os"
 	"time"
 
 	"github.com/gorilla/mux"
@@ -42,8 +44,6 @@ import (
 	"github.com/matrix-org/dendrite/setup/config"
 	"github.com/matrix-org/dendrite/setup/mscs"
 	"github.com/matrix-org/dendrite/userapi"
-	"github.com/matrix-org/gomatrixserverlib"
-
 	"github.com/sirupsen/logrus"
 
 	_ "github.com/mattn/go-sqlite3"
@@ -72,7 +72,21 @@ func main() {
 		}
 	*/
 
+	// iterate through the cli args and check if the config flag was set
+	configFlagSet := false
+	for _, arg := range os.Args {
+		if arg == "--config" || arg == "-config" {
+			configFlagSet = true
+			break
+		}
+	}
+
 	cfg := &config.Dendrite{}
+
+	// use custom config if config flag is set
+	if configFlagSet {
+		cfg = setup.ParseFlags(true)
+	} else {
 		cfg.Defaults(true)
 		cfg.Global.ServerName = gomatrixserverlib.ServerName(ygg.DerivedServerName())
 		cfg.Global.PrivateKey = ygg.PrivateKey()
@@ -92,6 +106,7 @@ func main() {
 		if err = cfg.Derive(); err != nil {
 			panic(err)
 		}
+	}
 
 	base := base.NewBaseDendrite(cfg, "Monolith")
 	defer base.Close() // nolint: errcheck