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4 Docker for developers

4-Docker_for_developer

• Intro
• Basic usages
• Unit Tests
• Other use cases
• Challenges

Intro

• Docker is popular

• Focus on deployment (with all k8s, swarm, ecs and stuff)

• You can also use docker on a daily bases

  • 1 developer
  • 1 laptop
  • Without saying that you use Docker :)
    => Based on Jessie Frazel stuff

Basic usages

1. --rm
2. --volume

docker run --rm \
                     --volume $WORKSPACE:/somewhere/in/the/container/according/to/the/software/best/practices
                    maven:4.0.4
                    package

1. links
2. ‘-it’

=> Ephemeral, reproducable, fast shell environment

Unit Tests

Proble usecase

• Test Matrix
• Make a docker images for every system you need
• Same RUN command
• Reproducable

• Explicit and versioned dependencies (when relying on system packages)

• Complex “Topology” testing (Infrastucture)

• Run the really important process component into a container

• Use compose + Links

• Simulating load

• Easy DB state reset

• Nothing to “reset”

Other use cases

• Integration Tests
• Mocking services
• Demos
• Data migration test

• “Data” containers

• Shared and reproducable environment in Team

• With private registry

Challenges

• Shared stuff
• Secrets
• config
• Everything that is not “Runtime” related