Traefik in front of other reverse proxy takes several minutes to work (otherwise 404)

Traefik Traefik v2
1

I use Traefik in front of a self-hosted application called Ryot.
This worked fine until there was an update to Ryot which apparently introduced Caddy as a reverse proxy inside the container image.
Now when I start the container it takes ~5 min until I can reach Ryot through Traefik.
Until then, I just get 404 page not found.
Weirdly however, I get an immediate response when I request Ryot from inside its container like curl -L localhost:8000.

I have already described this issue to the Ryot dev who sees no issue on his end.
There you also find some logs and my docker compose.

2

ryot has a depends_on for the database. Maybe that takes long, then ryot only gets a healthy status very late and Traefik waits for it.

Try to run docker ps multiple times during startup to monitor health status of all 3.

3

Thanks but it even happens when the db has been up and healthy for long and removing the depends_on does not fix it either.