FWIW, the default "TurnKey Django app" is only meant as a (super simple) "example app" and to provide a landing page for users launching the appliance. So in essence, you're "doing it right". :)

I should further note, that whilst my knowledge of Linux in general and TurnKey in particular is quite strong, I know next to nothing about Django and not that much more about Python (whilst I am getting much better with Python of late, my knowledge is still fairly rudimentary).

Having said all that, a 404 is server/file not found. The fact that you say that when you browse to your server, the URL appears to be being modified (i.e. the trailing '/' being added), suggests that it's not at all network related, but is likely related to you Apache config.

Beyond that, assuming that the path /var/www/sys/main/wsgi.py actually exists, it seems like a weird one. As a general rule, errors within Django itself (including Django config) are more likely to give you a 504 (when the Apache server can't connect to your python backend). Again that makes me suspect that it is related to your Apache config.

So a couple of quick thoughts. How have you created this new Apache config? Did you overwrite the default django.conf? Or have you created a new Apache config file (and disabled the default one)? It sounds like the former, but either way, have you restarted Apache to apply the updated config? FYI most Linux services read their config at start and won't re-read config to apply any changes unless you explicitly tell them to.

So even though it likely doesn't apply, if you have created a new Apache config file for your app (e.g. /etc/apache2/sites-available/new-app.conf) you would need to disable the default site config and enable your new site config, and finally restart Apache:

a2sdissite django
a2ensite new-app
service apache2 restart

Assuming that you've done that and it still isn't working, the next step I'd take is to check the Apache error log. Hopefully that will provide some insight into what might be going wrong. The (default) error file should be found at: /var/log/apache2/error.log. To get the last few lines of it (most likely what you want:

tail /var/log/apache2/error.log

Hopefully that might give you some ideas on what is going on. Please feel free to post it if you want me to provide some input (although I'm not sure how useful that might be...)

The other thing that jumps out at me (although not at all sure if this is related to this issue or not) is that you note the following:

• virtualenv, contains the Django project and several packages
• Django (2, 1, 6, 'final', 0)
• Python 3.6.8

The virtualenv bit sounds all good, but have you installed Python 3.6 yourself? TurnKey v15.x ships with the Debian 9/Stretch default Python 3.5.3 and AFAIK (I could be wrong here) to use Python 3.6, regardless of virtualenv (unless there is someway to actually install it within the virtualenv itself that I'm unaware of?) you'd have to install that on your server and ensure that it's available in your path.

Also, the TurnKey Django appliance ships with the Debian Django package, which is v1.10.7 (FWIW v1.11.18 is in backports, but that seems irrelevant here). AFAIK, there is nothing stopping you from using a newer version of Django (e.g. install via pip), but it possibly be better to remove the default bundled one to avoid risk of confusion (although using a venv should solve that really I guess).

I hope that all makes sense. If you want me to elaborate on anything, please ask.

I'm not so familiar with Django, but I play with Python a bit. Assuming that the stacktrace from the Apache log is consistent with a "normal" python stacktrace, it looks like it can't find a module (that I assume you're importing somewhere) called 'dj'.

I have no idea whether that should be a part of Django or something custom you've included ('dj' is suspiciously the first letters of Django, but that may be coincidental).

It's probably worth providing a little more info re default Apache WSGI integration. If you are happy to run with Python 3.5 (as per installed by default) then it should "just work". Our Django appliance comes pre-installed with the Apache WSGI module compiled against the default Python3.

According to the pypi page for mod_wsgi it looks like if you want to install via pip, then you'll also need to install the development Apache package. To quote the page:

If you are running Debian or Ubuntu Linux with Apache 2.4 system packages, regardless of which Apache MPM is being used, you would need both:

apache2

apache2-dev

Apache2 is (obviously) already installed, so you'll just need to install that dev package. Do that like this:

apt update
apt install apache2-dev

Perhaps also worthy of note, assuming that you are ok with using the system-wide Debian pip package for Python3, you should be able to use that like this:

pip3 install mod_wsgi

It is possible that pip3 is not pre-installed (it probably should be though). So if the above gives an error, install pip3 like this:

apt update
apt install python3-pip

Although as I note above, none of that should be required if you're ok with using Python 3.5, as the default pre-installed mod_wsgi should do the trick.

As something of an aside, but perhaps useful FYI, by default in Debian 'python' is Python2 (2.7). If you want Python3, then you need to explicitly invoke it with python3. Also a number of Python libraries are packaged and pre-tested for use in Debian. They will almost always be older that you'll get on Pypi, but can be a good option if they suit your purpose. Generally their names are (assuming you want the python3 variant) 'python3-<lib-name>. The Debian package search page can be a really useful resource for finding Debian pacakges.

Hope that helps.