volgen: Load default volfiles on Glusterd2 start

Also generates default templates if not exists

Fixes: #1111 and #1190
Signed-off-by: Aravinda VK <avishwan@redhat.com>

glusterd2/main.go

@@ -16,6 +16,7 @@ import (
 	"github.com/gluster/glusterd2/glusterd2/servers"
 	"github.com/gluster/glusterd2/glusterd2/store"
 	gdutils "github.com/gluster/glusterd2/glusterd2/utils"
+	"github.com/gluster/glusterd2/glusterd2/volgen"
 	"github.com/gluster/glusterd2/glusterd2/xlator"
 	"github.com/gluster/glusterd2/pkg/errors"
 	"github.com/gluster/glusterd2/pkg/firewalld"
@@ -127,6 +128,11 @@ func main() {
 		defer exporter.Flush()
 	}
 
+	// Load default volfile templates
+	if err := volgen.LoadDefaultTemplates(); err != nil {
+		log.WithError(err).Fatal("Failed to load Volgen templates")
+	}
+
 	// Start all servers (rest, peerrpc, sunrpc) managed by suture supervisor
 	super := initGD2Supervisor()
 	super.ServeBackground()