cloud/bmaas/server: do not start BMDB session per RPC

Fixes https://github.com/monogon-dev/monogon/issues/198

Change-Id: Ia99b9a47bfc9ae6de0b9e12e13add891dea289a5
Reviewed-on: https://review.monogon.dev/c/monogon/+/1567
Reviewed-by: Leopold Schabel <leo@monogon.tech>
Tested-by: Jenkins CI
diff --git a/cloud/bmaas/server/agent_callback_service.go b/cloud/bmaas/server/agent_callback_service.go
index b6e0e71..155c5de 100644
--- a/cloud/bmaas/server/agent_callback_service.go
+++ b/cloud/bmaas/server/agent_callback_service.go
@@ -39,8 +39,7 @@
 		return nil, status.Error(codes.InvalidArgument, "machine_id invalid")
 	}
 
-	// TODO(q3k): don't start a session for every RPC.
-	session, err := a.s.bmdb.StartSession(ctx)
+	session, err := a.s.session(ctx)
 	if err != nil {
 		klog.Errorf("Could not start session: %v", err)
 		return nil, status.Error(codes.Unavailable, "could not start session")