If this is a new deployment, you may be able to shell into the server and run the container locally on the server. Shell into the container and try basic things like opening the rails console from within the container. Try touching a record to make sure the database connection is working. If all of that checks out, try running the rails server. You should have an entry point shell script or a CMD in the dockerfile which starts up the rails process. Typically, what I've found is that the deployment will go through, but there's something missing that keeps the rails server from running properly.