Re: Hosting pgAdmin4 behind nginx and at /pgdmin, for mortals

OK, I got it working. This is how...

On Mon, 25 Feb 2019 at 23:25, Shaheed Haque <srhaque(at)theiet(dot)org> wrote:
>
> Hi,
>
> I'm a relative noob when it comes to the world of nginx, wsgi and so
forth, but I do have several other things working (a Django app under
gunicorn and the RabbitMQ web UI directly behind nginx). However, I'm
rather stuck getting pgAdmin4 to run at http://mydomain.com:80/pgadmin
behind nginx. Is there a simple, up-to-date example of how to do this (I'm
running the latest, v4.2, of pgAdmin4)?
>
> I'm aware of threads such as
https://www.postgresql.org/message-id/2197768425D7F5479A0FFB3FEC212F7FF602B871%40aesmail.surcouf.local,
and several others but not been able to come up with a clear approach:
>
> One of the several variables I'm struggling to understand is the choice
of whether to run pgAdmin4.py on port 5050 directly behind nginx, or as a
WSGI app under gunicorn. I assume the latter should be easier to set up,
but I've tried both (modelled on what I have working, and various
references). One combination I tried was:
>
> - Creating a softlink from pgadmin4.py to pgAdmin4.wsgi
> - Using gunicorn to run the pgadmin4.py to a unix domain socket like this:
>
> $ /usr/local/bin/gunicorn -w 1 --bind unix:/home/ubuntu/pgadmin.sock
pgadmin4:application
>
> - Serving behind nginx like this:
>
> location /pgadmin {
> rewrite ^/pgadmin/(.*) /$1 break;
> include proxy_params;
> proxy_pass http://unix:/home/ubuntu/pgadmin.sock;
> }
>
> But all I get is a stubborn 404. Any pointers welcome...

First, I got over the 404s (caused, it seems, by me forgetting just how
much my browser had cached :-0). The next problem was with the nginx config
fragment: as soon as pgAdmin responded, it of course started the browser
looking for top level URLs such as /browser and /static which are obviously
not under /pgadmin. The to this key was a piece of code in
https://stackoverflow.com/a/50515636/6332554, which basically adds the
concept of a SCRIPT_NAME by hacking a small wodge of code into pgAdmin4.py.

The SCRIPT_NAME is set by an nginx fragment like this:

location /pgadmin {
rewrite ^/pgadmin/(.*)$ /\$1 break;
include proxy_params;
proxy_pass http://unix:/home/$CLOUD_USER/pgadmin.sock;
proxy_set_header X-Script-Name /pgadmin;
}

In addition to that change, as previously noted, I needed to create a link
to pgAdmin4.wsgi to allow gunicorn to pick it up. I change the name I used
so I ended up with the link being "wsgi.py" -> "pgAdmin4.py", so the the
corresponding gunicorn command is something like this:

gunicorn ... --bind unix:/.../pgadmin.sock wsgi:application

Now, IIUC, the notion of SCRIPT_NAME is somewhat standard, and needed to
solve this issue of running pgAdmin in server mode, but sharing the domain
with other applications. Would there be interest in making the needed code
an integral part of pgAdmin? If so, I'd be happy to file a feature request.

Thanks, Shaheed