express-session does not work and req.session returns undefined

Heya @piootra,

There could be a couple of issues here, let’s try and go through them and see if they would help:

1. Check Node.js Versions: Ensure that the Node.js version on your droplet is the same as or compatible with the version you used on your local machine. Differences in Node.js versions can sometimes lead to unexpected behavior.

2. Environment Variables: If your application uses environment variables (e.g., for setting session secrets or configuration settings), ensure they are correctly set on your droplet. These variables might not be automatically transferred with your files.

3. Install Dependencies: Make sure all dependencies, including express-session, are correctly installed on the droplet. Run npm install in your project directory to ensure all necessary packages are installed.

4. Session Store: If you’re using a session store (like Redis, MongoDB, etc.), ensure that it’s correctly configured and accessible from your droplet. Network configurations or firewall settings could prevent your application from accessing the session store.

5. Cross-Origin Requests: If your front-end and back-end are hosted separately, ensure that your CORS (Cross-Origin Resource Sharing) settings are correctly configured to allow requests from your front-end.

6. Logging and Debugging: Add more logging around your session handling code to get more insights into what might be going wrong. Check the logs for any errors or warnings that might indicate the source of the problem.

7. File Permissions: Ensure that the user running the Node.js process on your droplet has the correct permissions to access all the files and directories used by your application.

8. Web Server Configuration: If you’re using a web server like Nginx or Apache as a reverse proxy, ensure it’s correctly configured to handle sessions. Some proxy settings can interfere with session handling.

Hello there, I spent days on a similar error, I was using passport and it just did not work. I reached out to few communities as well, could not get it to work, hence not sure about the root cause. later when I used cookies , i was not able to set it due to public suffix listing. This might have been an issue for session as well. Not sure if this is relevant here , dropping it anyway.

Hope you find it!