Continue reading: How to setup Dockerized testing

How to setup Dockerized testing

This article is the second in a series about system testing:

  1. Dockerized testing vs end-to-end testing
  2. How to setup Dockerized testing
  3. Readable Java system tests with good old JUnit

You may want to read Dockerized testing vs end-to-end testing first.

How to setup Dockerized testing?

A prerequisite for running your tests against a dockerized environment is of course that the service you want to test is packaged as a Docker image. Also, all of the services which the System Under Test (SUT) depends on needs to be dockerized. If you don’t have that, your environment is not fully dockerized and you will suffer the consequences of having to test against external services.

If your SUT is packaged as a Docker image and has no dependencies on other services, you can just start it using “docker run” and run your tests against it. However, usually services have one or more dependencies to other services, such as its own database, a queue and perhaps a external RESTish service that returns nasty XML. You want each of these services in their own container. To spin up a bunch of docker containers, you can use docker-compose.

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Continue reading: Dockerized testing vs end-to-end testing

Dockerized testing vs end-to-end testing

I recently rewrote the end-to-end tests for a service. This brought up the question of what we should test in the end-to-end (e2e) tests vs our Dockerized tests.

This article is the first in a series about system testing:

  1. Dockerized testing vs end-to-end testing
  2. How to setup Dockerized testing
  3. Readable Java system tests with good old JUnit

e2e tests vs dockerized tests

Since the original e2e tests were written, we (my team) have also introduced another type of tests. We call them “dockerized system tests”. These are similar to the e2e tests. They also test the connections between services in the system, and how the system works as a whole. One key difference between e2e tests and dockerized tests is that the dockerized tests do not test the system when it is deployed the way we deploy it in staging and production environments. Our dockerized tests bring up all services in a single machine, and we usually don’t set up redundancy, clustering, load balancers and such things.

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