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Make Tests Fast Again

Parallel Tests With Docker Containers

Rohit Joshi

CloudFactory

https://www.linkedin.com/in/rohitrox/

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An important part of a

good development experience

is

a fast feedback loop from the tests.

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Create Flexible and Replicable

test environment that enables us to

run tests in parallel.

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  • We want to run our group of tests in very isolated so that running one test doesn’t give other tests any side effects.
  • We don’t want to install too much external dependencies
  • We want to be developer friendly
  • We want to be reliable/consistent and configurable
  • Runnable in our local machine and in CI servers

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parallel-tests

Virtual Machines

knapsack

Existing Solutions

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Containers…

​

  • Create replicable environments
  • Run code in isolation
  • Build consistent build environments across many builds
  • Multiple tests in multiple containers

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  • Docker Compose
  • Docker registry
  • Docker for Mac/Windows/Ubuntu

TOOLS

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The Basic Concept

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DEMO

​

https://github.com/RohitRox/docker-rails-parallel-tests

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Runner Script

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QUESTIONS...