Error pages, like 404 or 50x pages, should be served directly by the frontend web server (nginx, caddy, apache), so Cozy apps have just to send 404/50x status code that can be catched.
Proxy is always installed in Cozy plateforms, I so suggest that it embed in its assets those error pages (with inlined styles / scripts if needed). We must also provide configuration exemples for aforemetioned mainstream webservers , that points to those pages in the FS, to catch those status errors.
Error pages, like 404 or 50x pages, should be served directly by the frontend web server (nginx, caddy, apache), so Cozy apps have just to send 404/50x status code that can be catched.
Proxy is always installed in Cozy plateforms, I so suggest that it embed in its assets those error pages (with inlined styles / scripts if needed). We must also provide configuration exemples for aforemetioned mainstream webservers , that points to those pages in the FS, to catch those status errors.