django-prometheus

Export Django monitoring metrics for Prometheus.io

Usage

Requirements

Django >= 1.4 (>= 1.8 is recommended)

Installation

Install with:

pip install django-prometheus

Or, if you're using a development version cloned from this repository:

python path-to-where-you-cloned-django-prometheus/setup.py install

This will install prometheus_client as a dependency.

Quickstart

In your settings.py:

INSTALLED_APPS = (
   ...
   'django_prometheus',
   ...
)

MIDDLEWARE_CLASSES = (
    'django_prometheus.middleware.PrometheusBeforeMiddleware',
    # All your other middlewares go here, including the default
    # middlewares like SessionMiddleware, CommonMiddleware,
    # CsrfViewmiddleware, SecurityMiddleware, etc.
    'django_prometheus.middleware.PrometheusAfterMiddleware',
)

In your urls.py:

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

Monitoring your databases

Currently, only SQLite and MySQL databases can be monitored. Just replace the ENGINE property of your database, replacing django.db.backends with django_prometheus.db.backends.

DATABASES = {
    'default': {
        'ENGINE': 'django_prometheus.db.backends.sqlite3',
        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    },
}

Monitoring your models

You may want to monitor the creation/deletion/update rate for your model. This can be done by adding a mixin to them. This is safe to do on existing models (it does not require a migration).

If your model is:

class Dog(models.Model):
    name = models.CharField(max_length=100, unique=True)
    breed = models.CharField(max_length=100, blank=True, null=True)
    age = models.PositiveIntegerField(blank=True, null=True)

Just add the ExportModelOperationsMixin as such:

from django_prometheus.models import ExportModelOperationsMixin

class Dog(ExportModelOperationsMixin('dog'), models.Model):
    name = models.CharField(max_length=100, unique=True)
    breed = models.CharField(max_length=100, blank=True, null=True)
    age = models.PositiveIntegerField(blank=True, null=True)

This will export 3 metrics, django_model_inserts_total{model="dog"}, django_model_updates_total{model="dog"} and django_model_deletes_total{model="dog"}.

Note that the exported metrics are counters of creations, modifications and deletions done in the current process. They are not gauges of the number of objects in the model.

Starting with Django 1.7, migrations are also monitored. Two gauges are exported, django_migrations_applied_by_connection and django_migrations_unapplied_by_connection. You may want to alert if there are unapplied migrations.

Monitoring and aggregating the metrics

Prometheus is quite easy to set up. An example prometheus.conf to scrape 127.0.0.1:8001 can be found in examples/prometheus.

Here's an example of a PromDash displaying some of the metrics collected by django-prometheus:

Adding your own metrics

You can add application-level metrics in your code by using prometheus_client directly. The exporter is global and will pick up your metrics.

To add metrics to the Django internals, the easiest way is to extend django-prometheus' classes. Please consider contributing your metrics, pull requests are welcome. Make sure to read the Prometheus best practices on instrumentation and naming.

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