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

Hi

On Fri, Mar 1, 2019 at 9:30 AM Shaheed Haque <srhaque(at)theiet(dot)org> wrote:

> 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
>

Thanks for your work on this.

I've committed a change to add the reverse proxy code, and to put some more
examples in the docs:
https://redmine.postgresql.org/projects/pgadmin4/repository/revisions/f401def044c8b47974d58c71ff9e6f71f34ef41d

FWIW, I think the reason that this was an issue for so long is that you
don't need the extra code if you use mod_wsgi or uWSGI - it's only needed
with Gunicorn. I'll let you guess which of those technologies I'm most
familiar with!

Unfortunately this commit won't make the 4.3 release later this week, but
it will be in 4.4. The instructions will still be good for scenarios other
than Gunicorn in a sub-directory though.

--
Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company