I’ve setup correctly collabora. It’s accesible from the local network (self signed certificate error but work). When I setup it using nginx reverse proxy manager after adding the required config on the advanced tab, the reverse proxy goes offline and cloudflare gives me an error 526 (invalid ssl certificate).
Did you read the links I provided? Cloudflare has different levels security for the link between them and your proxy. The 526 error is specifically about self-signed certificates. Did you try their option (in their control panel) for when you have a self-signed certificate?
I’m not suggesting you have to permanently run things that way, but seeing if that addresses the Cloudflare error will help you continue to increment through the troubleshooting process.
Error 526 occurs when these two conditions are true:
Cloudflare cannot validate the SSL certificate at your origin web server, and
Which Docker container? All of your TLS ( HTTPS) termination is on your nginx reverse proxy, correct? Nginx Proxy Manager supports Lets Encrypt so there shouldn’t be any self-signed certificates involved.
Typically, if colocated with your reverse proxy, your Collabora container doesn’t need an SSL certificate installed on it, will have SSL disabled on it and will SSL termination enabled. This means your proxy handles the HTTPS connectivity on behalf of Collabora. And your proxy is where you end up doing all your certificate management.