Month: July 2017

Regression testing releases with Depicted (Dpxdt), Travis, & Saucelabs

Depicted is a release testing tool that compares before and after screenshots of your webpage, highlighting differences between the two.

Depicted supplements your release testing by allowing you to approve any visual changes a new release may cause.

I wrote a script during my time at Sprintly that would take a TravisCI build ID, pull related screenshots from our Saucelabs selenium tests, and upload them to a Depicted API server for comparison.

Before a new release would be deployed, we would manually run our Depicted release script and check and approve any changes.

This script was integrated as a Django management command for ease of use. Check out the full script below with comments.

Django, Redis & AWS ElastiCache primary/replica cluster

AWS’s ElastiCache service is a convenient way to launch a Redis cluster. If you’re using Django, both django-redis-cache and django-redis packages support an ElastiCache Redis instance. If you are launching ElastiCache Redis with any amount of replicas, some additional master-slave configuration is needed in your Django settings.

Here is an example of an ElastiCache Redis cluster with a primary instance and two replicas:

The following is an example of the correct settings for this cluster if you’re using django-redis-cache backend:

CACHES = {
    'default': {
        'BACKEND': 'redis_cache.RedisCache',
        'LOCATION': [
            "test-001.730tfw.0001.use1.cache.amazonaws.com:6379",
            "test-002.730tfw.0001.use1.cache.amazonaws.com:6379",
            "test-003.730tfw.0001.use1.cache.amazonaws.com:6379"
        ],
        'OPTIONS': {
            'DB': 0,
            'MASTER_CACHE': "test-001.730tfw.0001.use1.cache.amazonaws.com:6379"
        },
    }
}

https://django-redis-cache.readthedocs.io/en/latest/advanced_configuration.html#master-slave-setup