@julian I found this: https://github.com/NodeBB/NodeBB/issues/4734
Using the certbot configuration, I edited /etc/nginx/sites-available/default
Leaving the certbot managed parts as they are, my custom config looks like this now:
proxy_set_header X-Forwarded-Proto $scheme;
location / {
proxy_pass http://127.0.0.1:4567;
}
The special part is the x-forwarded-proto line, that's what I was needing all along.
And in /home/nodebb/nodebb/config.json I'm setting the URL with https:
{
"url": "https://forums.mydomain.com",
"secret": "<REDACTED>",
"database": "mongo",
"port": "4567",
"mongo": {
"host": "127.0.0.1",
"port": "27017",
"username": "nodebb",
"password": "<REDACTED>",
"database": "nodebb",
"uri": ""
}
}
This resolved my problem.