RE: Hosting pgAdmin4 with Apache/WSGI

I share your pain.
I do have it working but as a root app and it took me a while to work through the docs and fill in the blanks.
I think Dave was looking at making server install much easier but not sure if anything was implemented in the next version.
Regarding issue #2 running the app as a subdirectory this was broken in 1.6
As you have found the docs won’t give you a working solution.
You can work around this by running the app in the root of apache but that’s not a great solution.
I am waiting on 1.7 to fix this but there is no info on release as of yet.

From: Gabriel Sánchez [mailto:gabrielesanchez(at)gmail(dot)com]
Sent: 14 September 2017 17:32
To: pgadmin-support(at)postgresql(dot)org
Subject: Hosting pgAdmin4 with Apache/WSGI

Hi team,

Thanks for the hard work you've put in to develop pgAdmin4 and provide support to the community. I'm writing to ask for your help to set up pgAdmin4 in server mode under Apache with WSGI. I'm running Ubuntu 16.04 Server and installing pgAdmin4 version 1.6 with Python 2.7.12. A couple of issues are getting in the way.

Issue #1 Installation

I struggled to install pgAdmin4 with the online documentation, being unfamiliar with Python and WSGI. I followed the instructions on the pgAdmin website but I was not getting the pgAdmin page on my browser.

I turned on debug logging in apache and was getting the following (details redacted):

####
mod_wsgi (pid): Target WSGI script '/opt/pgadmin4/virtualenv/lib/python2.7/site-packages/pgadmin4/pgAdmin4.wsgi' cannot be loaded as Python module.
mod_wsgi (pid): Exception occurred processing WSGI script '/opt/pgadmin4/virtualenv/lib/python2.7/site-packages/pgadmin4/pgAdmin4.wsgi'.
Traceback (most recent call last):
File "/opt/pgadmin4/virtualenv/lib/python2.7/site-packages/pgadmin4/pgAdmin4.wsgi", line 17, in <module>
import config
File "/opt/pgadmin4/virtualenv/lib/python2.7/site-packages/pgadmin4/config.py", line 24, in <module>
from pgadmin.utils import env, IS_PY2, IS_WIN, fs_short_path
File "/opt/pgadmin4/virtualenv/lib/python2.7/site-packages/pgadmin4/pgadmin/__init__.py", line 17, in <module>
from flask import Flask, abort, request, current_app, session
ImportError: No module named flask
####

But flask *was* installed in the virtual environment! I also ran setup.py within the virtual environment. After hours of reading forum and mailing list posts, scanning error logs, and trying things, I was able to get to the pgAdmin4 landing page. As best I can tell, the issue was that I installed pgAdmin4 in a virtual environment, under /opt/pgadmin4/virtualenv, but apache2 wasn't using that virtual environment. The solution was to add the following to pgAdmin4.wsgi right before "import config":

activate_this = '/opt/pgadmin4/virtualenv/bin/activate_this.py'
execfile(activate_this, dict(__file__=activate_this))

Is this the right solution, or is there a better fix to this? Note that the download instructions of the website recommend installing pgAdmin inside a virtual environment (I had to learn what that was and how to set it up), and the Server Setup instructions in the documentation don't mention the need to add these lines.

If this is the right solution, it would help to clarify in the documentation, and perhaps to add the hint to the error log. I'm including this here hoping that others with the same problem will find this post and it will save them hours of troubleshooting. A detailed walk-through in the documentation would've been super helpful. If you'd like, I can share my setup as a walk-through for posting on the website once I get it all running well.

Issue #2 Hosting within web subdirectory

I want to host pgAdmin within a web subdirectory, e.g. example.com/pgadmin<http://example.com/pgadmin>, since the server has a website on root, e.g. example.com<http://example.com>. I have the following apache site configuration (details redacted):

<IfModule mod_ssl.c>
<VirtualHost _default_:443>
ServerName ***
ServerAdmin ***
DocumentRoot /var/www/html
ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined

SSLEngine on
SSLCertificateFile ***
SSLCertificateKeyFile ***
SSLCACertificateFile ***

WSGIDaemonProcess pgadmin processes=1 threads=25
WSGIScriptAlias /pgadmin /opt/pgadmin4/virtualenv/lib/python2.7/site-packages/pgadmin4/pgAdmin4.wsgi

<Directory /opt/pgadmin4/virtualenv/lib/python2.7/site-packages/pgadmin4>
WSGIProcessGroup pgadmin
WSGIApplicationGroup %{GLOBAL}
AllowOverride None
Require all granted
</Directory>
<Location "/pgadmin">
SSLVerifyClient require
SSLVerifyDepth 1
</Location>
</VirtualHost>
</IfModule>

This gets me the pgAdmin landing page, but nothing works. Clicking on "Add New Server" does nothing. Clicking on "Configure pgAdmin" opens up a dialog that says "Category is not selected." Nothing shows up in the Browser.

If I change the apache config to host under / instead of under /pgadmin, things do work. I see the "Servers" node in the browser, and the Create Server dialog pops up when I click on "Add New Server". I am able to connect to the database.

What configuration changes are necessary to get pgAdmin to work within a subdirectory, e.g. /pgadmin?

Issue #3 Using peer authentication

Is there a way to use peer authentication without passwords? I had to setup the connection without SSL and connecting to localhost, with a password. I'm already protecting the landing page with client certificate authentication, and pgAdmin itself requires password authentication, so I figure another password isn't necessary. (Right?) The documentation says "On Unix based systems, the address field may be left blank to use the default PostgreSQL Unix Domain Socket on the local machine..." but pgAdmin is requiring me to enter a host name in the connection tab or a host address in the advanced tab.

Should I use SSL for traffic within the server (between the database and the client) if I'm not sharing the server with anyone?

Any other configuration suggestions or tips are welcome.

Thanks in advance for your help.

Regards,
Gabriel