Docker & Testing in Docker

Why Docker?

Speed. Speed. Speed.
Making dev->test->prod easier and faster
"make my code run the same way on two different machines"
Reduce complexity of developing code for distributed systems
Reduce complexity of deploying code to the cloud
Reduce complexity of updating code in the cloud

Docker Editions

Docker is no longer just a "container runtime"
Docker moves fast, it matters how you install it
Docker CE (Community Edition)
Three major types of installs: Direct, Mac/Win, Cloud
Linux (different per distro) (don’t use default package)
Docker for Windows (or legacy Docker Toolbox)
Docker for Mac (or legacy Docker Toolbox) (don’t use brew)
Docker for AWS/Azure/Google

Docker for Mac

Use Docker for Mac, from store.docker.com
More features then just a Linux VM
Uses "xhyve" with tiny Linux VM for Linux Containers
Terminal/iTerm native

Containers vs VMs

Container VS Virtual Machine
Containers aren’t Mini-VM’s
They are just processes
Limited to what resources they can access (file paths, network devices, running processes)
Exit when process stops

Docker CLI

docker version
docker info
docker command line structure

docker <command> <sub-command> (options)

Let's create our first docker container

docker run -d mongo
docker container ls
docker run --name mongo -d mongo
docker run --name mongo -d mongo // Will throw an error
docker container ls
docker container logs mongo
docker container stop mongo
docker container stop [id of first mongo]

docker run --name mongo -d mongo // Will throw an error
docker start mongo
docker container stop mongo

docker container ls -a
docker container rm mongo
docker container ls -a

Image vs Containers

An Image is the application we want to run
A Container is an instance of that image running as a process
You can have many containers running off the same image
Docker's default image "registry" is called Docker Hub (hub.docker.com)

docker container run --publish 80:80 nginx

Downloaded image 'nginx' from Docker Hub
Started a new container from that image
Opened port 80 on the host IP

Task

Run a nginx, a mysql, and a httpd (apache) server
Run all of them --detached (or -d), name them with --name
nginx should listen on 80:80, httpd on 8080:80, mysql on 3306:3306
When running mysql, use the --environment option (or -e) to pass in MYSQL_RANDOM_ROOT_PASSWORD=yes
Use docker container logs on mysql to find the random password it created on startup
Clean it all up with docker container stop and docker container rm (both can accept multiple names or ID's)
Use docker container ls to ensure everything is correct before and after cleanup

Integration with Testcafe

TestCafe provides a preconfigured Docker image with Chromium and Firefox installed. Therefore, you can avoid manual installation of browsers and the testing framework on the server.

docker pull testcafe/testcafe

Prepare Tests

Create a folder called dockerTests
Create a file called test.js that opens zemoga website, navigate to jobs page.
Try to submit the form
Test for error message to appear
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Run TestCafe from the docker image.

docker run
    -v ${TEST_FOLDER}:/tests
    -it testcafe/testcafe ${TESTCAFE_ARGS}

docker run
    -v /path/to/dir/dockerTests:/tests
    -it testcafe/testcafe 'chromium --no-sandbox,firefox' /tests/test.js
    --rm