## The problem
Issue zeabur/zeabur#77 (closed, 5 comments): A Docker container deployed on Zeabur with a custom port (8090) returns 502 on its bound domain, while the container logs show no errors. The reporter asked whether non-80/443 ports are exposed at all. (Issue filed in Chinese; paraphrased.)
## What to do
Platform bug, fixed by the Zeabur team. Maintainer yuaanlin confirmed the fix: Zeabur now automatically maps the outward port from the EXPOSE instruction in your Dockerfile, so a container listening on 8090 gets routed correctly through the bound domain. If you hit this 502 pattern, first make sure your Dockerfile has an EXPOSE line for the port your app actually listens on, then redeploy. No manual port mapping or reverse-proxy config is needed on current Zeabur.