One of my Cloudflare Tunnels is returning a Bad Gateway error

Hi there,

For a 502 Bad Gateway on a tunnel, you will need to check the logs for cloudflared. Basically it means that the connection between Cloudflare and the tunnel is active, but the tunnel cannot access your origin service.

If using docker, run docker ps to get the container ID and then run docker logs <id> to grab the logs.

Note also for Docker, if you are using a localhost or 127.0.0.1 service this might not work due to network isolation.