How do I troubleshoot my Docker container running Express.js?

I'm having issues with my Docker container running an Express.js app. It keeps crashing.

Let's start by checking the logs of your Docker container. You can use the command docker logs <container_id> to see what's going wrong.

I ran the command, and it shows a 'Cannot find module' error.

This usually means that the module isn't installed in your container. Make sure your Dockerfile includes the necessary npm install command.

I added that, but now I'm getting a 'permission denied' error when trying to access a file.

This could be a file permission issue. You might need to adjust the permissions in your Dockerfile or use a different user to run the container.