So I've successfully deployed my docker image to Synology, and I can access it just fine internally with localhost on http via normal IP and port. But when I set up reverse proxy, and I try to connect via WAN, I get error 404. Both on PC and Android phone
When I check the error message, it says "Error 404 Not Found: Invalid origin: http://my-ddns.domain.name (code 404)".
What is the reason for this, and why does the error say that I have problem connecting to "htttp" when I spesifically added my reversed proxy https adddress on the "Joplin Server URL" line field?
Doesn't Synology have a remote access feature that you can Implement on your phone so when you are away from home you can link to your Synology server directly?
If not you might want to look into a program called tailscale. You can run this product on each device so you would put the Synology server or the Joplin server if it's a separate instance of Linux login to the tail scale account and if each server is in the same tail scale login account they will see each other with a private ip. Network and there is a version of tail scale for Android and I believe iOS but I'm not sure.
I use tail scale regularly to access servers inside my house on my local Wi-Fi without having to set up any reverse proxies or port forwarding or anything like that. Your phone and your Synology server will effectively be on the same IP subnet that has end to end encryption and you can do it with their free plan.
I just checked and there is supposedly a tail scale application add-in for Synology making it very easy to implement.
Here are instructions that I created with chat GPT. You may need to adjust them a little bit but it should give you the general idea.
