We have spent days working on an issue where when we curl’d our sites we were getting the error
SL read: error:00000000:lib(0):func(0):reason(0), errno 104
Cert was ok but Curl could not touch the site…
Found out it was due to a misconfiguration in NGINX.
For you that care and find this, to fix make sure when you define a server to use 443 and a cert that you define all of it’s config option.
For example we were missing
ssl_protocols TLSv1.2 TLSv1.1 TLSv1;
That’s silly you should have that defined… We did in our default and we assumed that the site would inherit this.
A little know fact is that NGINX will allow inherit if you don’t redefine the cert so we took out the redefined cert (because it was the same as the default) and voila! the error was gone.
Hope this helps someone.