It is possible to break Nginx based install with upload progress by enabling nginx_ssl feature

Normally Provision runs test to check if Nginx has been compiled with (contrib) upload progress module and adds extra line in the /var/aegir/config/nginx.conf file:

upload_progress uploads 1m;

Then it is using the nginx_advanced_include.conf config include in every site vhost to leverage upload progress feature.

However, when you enable the nginx_ssl feature in Aegir *after* you provisioned some sites, the server node will be re-verfied, but this time Provision will fail to add expected (and now required) line in the /var/aegir/config/nginx.conf file, which will prevent Nginx reload and when you will try to force Nginx restart (or reboot the server) it will not be able to start at all because of fatal error:

root@server:/var/aegir/config/server_master# service nginx reload
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: [emerg] zero size shared memory zone "uploads"
nginx: configuration file /etc/nginx/nginx.conf test failed

To get your sites back online you will need to either add this line manually or re-verify all sites, so their vhosts will include nginx_simple_include.conf instead, which doesn't use the upload progress feature.

Of course you can also just disable the nginx_ssl feature in Aegir, but if you are already using it for one or more sites, you are locked in and have to add that line manually after every upgrade or server verify.

This is probably because the function save_server() {} exists only in the provision/http/Provision/Service/http/nginx.php file but is not used (and doesn't exist) in the provision/http/Provision/Service/http/nginx/ssl.php file.

We will test it ASAP and submit a patch.