Open Infrastructure

h1. Django hosting by ungleich

{{toc}}

h2. Status

This document is **IN PRODUCTION** (since 2016-04-08). 

Pricing can be found on the "ungleich products page":https://ungleich.ch/u/products/django-hosting/.

h2. Version 2: Kubernetes Based (active as of 2023)

h3. Deployment preparation

* Create a (docker) container that contains everything the django app needs to run

* The container should listen on port 9000

** This allows running django on port 8000 and potentially an nginx or similar inside for serving static files as well

* The container needs to read the database configuration from environment variables (see below)

h3. Database configuration

The database configuration is passed into the container using environment variables as follows:

<pre>

  POSTGRES_USER

  POSTGRES_DB

  POSTGRES_PASSWORD

  POSTGRES_HOST

</pre>

Additionally the following variable is passed in that needs to be interpolated (i.e. variables need to resolve):

<pre>

DATABASE_URL = postgres://$(POSTGRES_USER):$(POSTGRES_PASSWORD)@$(POSTGRES_HOST):5432/$(POSTGRES_DB)

</pre>

h3. Static (pre-compiled) files

If you want to serve static, pre-compiled files, add them into your container in */app/static*.

All files stored in that directory will be exposed using an integrated nginx.

h3. Data directory

If your application needs to store files to persistent storage, it should be stored below /data. Usually the following structure is used:

* DJANGO_MEDIA_ROOT = /data/media

h2. Version 1: VM Based (obsolete as of 2023)

h3. How to use

# Configure your app

# Deploy your app

# Install project specific python requirements into the pyvenv

# Restart uwsgi to restart your app

# Go to http://your-hostname/ and enjoy!

h3. Configure your app

h4. WSGI

* Ensure that there is _projectname_/wsgi.py in your project root

h5. Database

Add the following to your settings.py:

<pre>

DATABASES = {

    'default': {

        'ENGINE': 'django.db.backends.postgresql_psycopg2',

        'NAME': 'app',

    }

}

</pre>

h4. Static and media files

Static files should be placed in */home/app/app/static* and media files in */home/app/app/media*.

Use the following code for configuration:

<pre>

PROJECT_DIR = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))

STATIC_ROOT = os.path.join(BASE_DIR, "static/")

MEDIA_ROOT = os.path.join(PROJECT_DIR, 'media')

</pre>

Usually to generate/deploy the static files, you can use collectstatic:

<pre>

python manage.py collectstatic                                                             </pre>

h3. Deploy (first time)

You can login to your VM as user *app*:

<pre>

ssh app@MYHOSTNAME

git clone <path-to-your-project> ~/app

</pre>

* Deploy / update your app into the folder *~app/app* (that is the app folder in the home of the user app)

* We recommended to use git to deploy it

h3. Deploy (update)

<pre>

ssh app@MYHOSTNAME

cd ~/app

git pull

</pre>

h3. Install python requirements into the pyvenv

Pyvenv has been installed to *~app/pyvenv* for you.

Required packages for the hosting like PostgreSQL support and uwsgi support have already been placed.

You need to use pyvenv found in *~app/pyvenv*, as uwsgi loads this pyvenv before loading your app.

To install your requirements use:

<pre>

. ~/pyvenv/bin/activate

pip install ...

</pre>

h3. Restarting the app

* *sudo systemctl restart uwsgi*

h4. Viewing logfiles

* nginx access log: *tail -F /var/log/nginx/access.log*

* nginx error log: *tail -F /var/log/nginx/error.log*

* uwsgi log: *tail -F /var/log/uwsgi/app/app.log*

h3. Description of the stack

h4. Technologies

* Debian

* nginx

* PostgreSQL

* uwsgi

* python3 venv

h4. Configuration

* user "app"

** in group "adm" (to view logfiles)

* PostgreSQL with

** database "app"

** Listens only on localhost / socket (no remote connections)