Improvement to the NGINX error message presented when API is not running.

[markofu]

As previously chatted about ::

I believe it'd be nice to have an UI improvement for the API warning message within SecurityMonkey web application. I believe that this is unclear and typically happens when there is an issue with the SecurityMonkey scheduler due to the supervisorctl not staying up. Is it reasonable to configure the nginx 502 error message to point the admin to check the status of the scheduler and to restart (e.g. point them to here?

Something like -

#site-wide error pages
error_page 404 /404.html;
error_page 502 /502.html;

where the 404.html and 502.html files live in the domain root and encourages the admin to check if the scheduler is running.

I think these are the official nginx instructions here.

[scriptsrc]

@markofu - any interest in making a PR?

bonus points for having a fun picture in the 404.html.

[markofu]

@monkeysecurity sure, I'll have a look :)