Re: Hosting pgAdmin4 behind nginx and at /pgdmin, for mortals - Mailing list pgadmin-support

Downgrade psycopg2 to 2.7.7 (or whatever came before 2.8). Apparently they broke backwards compatibility:-(

I can login, but when I click on "Servers", nothing happens on screen
and the error log gets this:

[2019-04-04 16:10:10 +0000] [5850] [INFO] Starting gunicorn 19.9.0
[2019-04-04 16:10:10 +0000] [5850] [INFO] Listening at:
unix:/home/ubuntu/pgadmin.sock (5850)
[2019-04-04 16:10:10 +0000] [5850] [INFO] Using worker: gthread
[2019-04-04 16:10:10 +0000] [5853] [INFO] Booting worker with pid: 5853
2019-04-04 16:10:25,732: ERROR  flask.app:
'psycopg2.extensions.Column' object has no attribute '_asdict'
Traceback (most recent call last):
 File "/usr/local/lib/python3.6/dist-packages/flask/app.py", line
1813, in full_dispatch_request
   rv = self.dispatch_request()
 File "/usr/local/lib/python3.6/dist-packages/flask/app.py", line
1799, in dispatch_request
   return self.view_functions[rule.endpoint](**req.view_args)
 File "/usr/local/lib/python3.6/dist-packages/flask/views.py", line 88, in view
   return self.dispatch_request(*args, **kwargs)
 File "/usr/local/lib/python3.6/dist-packages/pgadmin4/pgadmin/browser/utils.py",
line 259, in dispatch_request
   return method(*args, **kwargs)
 File "/usr/local/lib/python3.6/dist-packages/pgadmin4/pgadmin/browser/utils.py",
line 309, in children
   children.extend(module.get_nodes(*args, **kwargs))
 File "/usr/local/lib/python3.6/dist-packages/pgadmin4/pgadmin/browser/server_groups/servers/__init__.py",
line 127, in get_nodes
   in_recovery, wal_paused = recovery_state(conn, manager.version)
 File "/usr/local/lib/python3.6/dist-packages/pgadmin4/pgadmin/browser/server_groups/servers/__init__.py",
line 52, in recovery_state
   status, result = connection.execute_dict(recovery_check_sql)
 File "/usr/local/lib/python3.6/dist-packages/pgadmin4/pgadmin/utils/driver/psycopg2/connection.py",
line 1202, in execute_dict
   desc.to_dict() for desc in cur.ordered_description()
 File "/usr/local/lib/python3.6/dist-packages/pgadmin4/pgadmin/utils/driver/psycopg2/connection.py",
line 1202, in <listcomp>
   desc.to_dict() for desc in cur.ordered_description()
 File "/usr/local/lib/python3.6/dist-packages/pgadmin4/pgadmin/utils/driver/psycopg2/cursor.py",
line 94, in to_dict
   ores = OrderedDict(self.orig_col._asdict())
AttributeError: 'psycopg2.extensions.Column' object has no attribute '_asdict'

It seems as though the version of psycopg2 is not what is expected,
rather than anything to do with "builtins.SERVER_MODE = True"? By way
of full disclosure, I do in fact have both psycopg2 AND
psycopg2-binary installed [1] but some quick experiments removing one
or other did not solve the problem.

Have I overlooked something?

Thanks, Shaheed

[1] this came up in another discussion recently, and it seems that I
ought to remove the psycopg2-binary though 4.2 was OK with this setup.

On Thu, 4 Apr 2019 at 15:04, Dave Page <dpage@pgadmin.org> wrote:

Hi

It worked fine when I tested it. If you don't get any errors and you get a login prompt, it should all be good.

On Thu, Apr 4, 2019 at 3:01 PM Shaheed Haque <shaheedhaque@gmail.com> wrote:

Hi Dave,

I'm just migrating to the fixes in 4.4. Can I just double check one

thing? In my original hack, I needed to create a link "wsgi.py" ->

"pgAdmin4.py", so the the corresponding gunicorn command is something

like this:

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

Now, in the documentation updates as part of this fix, the last

argument to that line reads "pgAdmin4:app" and not "wsgi:application".

The reason I though I needed to use the wsgi.py file is that it

contains these lines amongst other:

   # Ensure the global server mode is set.

   builtins.SERVER_MODE = True

I'm not sure if, by following the updated docs, I am missing a

necessary setting?

Thanks, Shaheed

On Tue, 5 Mar 2019 at 09:11, Dave Page <dpage@pgadmin.org> wrote:

You're welcome. Sorry it took so long to realise the main issue was only applicable to Gunicorn!

On Mon, Mar 4, 2019 at 6:29 PM Shaheed Haque <srhaque@theiet.org> wrote:

Dave,

Thanks for taking this forward, I look forward to 4.4! I also noted with interest that we can use "pgAdmin4:app" rather than my hacky link to the pgAdmin4.wsgi, so that means a completely hack-free solution :-).

Shaheed

On Mon, 4 Mar 2019 at 16:33, Dave Page <dpage@pgadmin.org> wrote:

Hi

On Fri, Mar 1, 2019 at 9:30 AM Shaheed Haque <srhaque@theiet.org> wrote:

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

On Mon, 25 Feb 2019 at 23:25, Shaheed Haque <srhaque@theiet.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

--

Dave Page

Blog: http://pgsnake.blogspot.com

Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com

The Enterprise PostgreSQL Company

--

Dave Page

Blog: http://pgsnake.blogspot.com

Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com

The Enterprise PostgreSQL Company