DockerCon EU 2018: How Docker Changed the Way We Test Our Software

Slide 1

Slide 1 text

SERGEI EGOROV Staff Engineer, Pivotal How Docker Containers Changed the Way We Test Our Software

Slide 2

Slide 2 text

“If I had an hour to solve a problem   I'd spend 55 minutes thinking about the problem   and 5 minutes thinking about solutions.” — Albert Einstein

Slide 3

Slide 3 text

“If I had an hour to fix a bug   I'd spend 55 minutes writing a test   and 5 minutes fixing the issue.” — Me

Slide 4

Slide 4 text

Software testing

Slide 5

Slide 5 text

Software testing Integration  Testing System  Testing Sanity  Testing Acceptance  Testing Regression  Testing UI  Testing Unit  Testing Smoke  Testing

Slide 6

Slide 6 text

Software testing Integration  Testing Unit  Testing System  Testing Dev Dev

Slide 7

Slide 7 text

• Fast • Simple • Catches bugs in the logic • Checks algorithms Unit testing

Slide 8

Slide 8 text

• Powerful • Challenging • Starts real databases • Catches bugs in integrations • Checks assumptions about other systems Integration testing

Slide 9

Slide 9 text

• Powerful • Challenging • Starts real databases • Catches bugs in integrations • Checks assumptions about other systems Integration testing

Slide 10

Slide 10 text

Cross-platform Isolated Reproducible CI friendly Fast 2 1 3 4 5 Integration testing challenges

Slide 11

Slide 11 text

Integration testing transformation Mocking

Slide 12

Slide 12 text

Integration testing transformation Mocking • DB logic is not tested • Assumptions, not facts

Slide 13

Slide 13 text

Integration testing transformation Mocking Local DBs

Slide 14

Slide 14 text

Integration testing transformation Mocking Local DBs • Not cross-platform • Complex installation process • Hard to isolate

Slide 15

Slide 15 text

Integration testing transformation Mocking Local DBs VMs

Slide 16

Slide 16 text

Integration testing transformation Mocking Local DBs VMs • Vagrant to the rescue • Slow • Port management is hard • Heavyweight images

Slide 17

Slide 17 text

Integration testing transformation Mocking Local DBs VMs Docker

Slide 18

Slide 18 text

Image Me

Slide 19

Slide 19 text

Simple

Slide 20

Slide 20 text

Integration testing transformation Mocking Local DBs VMs Docker Fig  (aka Docker Compose)

Slide 21

Slide 21 text

Declarative

Slide 22

Slide 22 text

Declarative R U UP?

Slide 23

Slide 23 text

Declarative Random ports?

Slide 24

Slide 24 text

Declarative DB per test?

Slide 25

Slide 25 text

IDE integration?

Slide 26

Slide 26 text

Integration testing transformation Mocking Local DBs VMs Docker Fig  (aka Docker Compose) Docker API

Slide 27

Slide 27 text

WHAT IF I TOLD YOU THERE IS AN API

Slide 28

Slide 28 text

No content

Slide 29

Slide 29 text

Testcontainers •http://testcontainers.org •Library instead of a tool −Throwaway instances of common databases, Selenium web browsers, or anything else that can run in a Docker container. −Takes care of not just starting, but also running & destroying your test’s dependencies. −Very robust environment discovery (Linux, Windows, Mac OS X, CI environments, Docker in Docker, etc) •OSS project −Originally created by Richard North −MIT licensed −A vibrant community of the testing-oriented people. •JVM first −Initially implemented as a Java library −Community-contributed ports: C#, Golang, NodeJS, Python, Rust −Plans to share the implementation between the languages