In the previous article, we looked at how to setup Prometheus and we got a feel of what it looks like to monitor a service. In this one, we'll be going straight into monitoring applications- Django Web apps, so if you're trying to figure out how to up your observability game, this article is for you!

Let's get into it!

Prerequisite

• Prometheus installed

• Basic understanding of how Prometheus works (Check my previous article)

• A functioning Django application you want to monitor.

Something you should keep in mind: Prometheus monitors applications through client libraries. Read the docs.

In this article, we'll be using django-prometheus to export the metrics of our Django App to Prometheus!

Installing and setting up django-prometheus

pip install django-prometheus

In your settings.py, add the following:

INSTALLED_APPS = [
   ...
   'django_prometheus',
   ...
]

MIDDLEWARE = [
    'django_prometheus.middleware.PrometheusBeforeMiddleware',
    .
    .
    .
    'django_prometheus.middleware.PrometheusAfterMiddleware',
]

In the urls.py of your Django project:

urlpatterns = [
    ...
    path('', include('django_prometheus.urls')),
]

Note:

1. This should be added in the urls.py of your Django project and NOT the Django app. Please review this article.

2. For more details on the django-prometheus package, read here.

3. Be sure to update your requirements.txt file

pip freeze > requirements.txt

Next, update your prometheus.yml file to look like this:

global:
  scrape_interval:     5s
  evaluation_interval: 5s

alerting:
  alertmanagers:

scrape_configs:
  - job_name: 'django-app'
    static_configs:
      - targets: ['127.0.0.1:8000']
        labels:
          group: 'server'

NOTE: If this section is unclear, refer to my previous article

Start your webserver and open 127.0.0.1:8000/metrics. You should have output like this:

To be able to access the Prometheus UI, start up your Prometheus server with this command

./prometheus --config.file=prometheus.yml
# Make sure you're in the prometheus-2.54.0.darwin-amd64 dir
# The name will vary depending on your OS/distribution ;)

You can now run queries in the Prometheus UI at http://127.0.0.1:9090/.

In the next one, we'll look at scraping custom metrics from our applications!

Cheers!