Not sure why but taking out the line:
    include common/locations.conf;
fixed the issue

On Tue, Nov 8, 2016 at 1:38 AM, Mike Jumper <mike.jumper@guac-dev.org> wrote:
On Sun, Nov 6, 2016 at 5:15 PM, Omer Iqbal <omitted@gmail.com> wrote:
> I was hoping to get some help with an NGINX reverse proxy issue I've run
> into.
>
> ...
>
> 3) Setup an internal reverse proxy at 192.168.1.31/guac using this setting:
>
> server {
> listen 80 default_server;
> listen [::]:80 default_server;
>   ...
>   location /guac {
>     proxy_pass http://192.168.1.32:8080/guacamole;
>     ...
>   }
>
> }
>
> -everything is working fine and guacamole displays correctly
>

OK - so Guacamole is confirmed accessible at 192.168.1.32:8080.

> 4) Setup an external reverse proxy at domain.tld/guac using this setting:
>
> server {
> ...
>   location /guacamole {
>     proxy_pass http://10.10.1.3:8080;

Can you confirm that Guacamole is accessible at 10.10.1.3:8080?

>
> -no display of guacamole
>

But what specifically do you see? Does Nginx respond with an error, or
is the HTTP connection refused outright? Do you see any relevant
messages Nginx error log?

- Mike