Learning Docker - Smashtest in docker

Learning how to create a docker container by creating a smashtest setup in docker.

github: learning-docker

Pre-requisites

Windows

• Windows 10 - 1903+
• Docker Desktop
• Docker installed onto your WSL - Linux
• Docker compose installed onto your WSL - Linux

Linux

• Docker
• Docker compose

Introduction

To learn docker I chose to “dockerise” an example smashtest test which would run against a browser(s). For this example the browsers and selenium grids(hub) are additional containers the main container communicates with.

DockerFile

FROM node:13.12.0-slim

WORKDIR /code/

COPY ./code/ .

For smashtest all I needed was a nodejs container which would run the smashtest node package.

The only other required code was to copy the smashtest files into the container.

For other containers that I may create in the future the container may need more setup via RUN, CMD and many other commands against the image to configure the container.

NOTE: That the contents of the DockerFile is what is required for a production deployment. A different docker-compose.yml may be required for production specific configuration.

docker-compose.yml

version: "3.7"
services:

  testserver:
    build: .
    image: smashtest-docker
    volumes:
      - ./code/:/code/

  firefox:
    image: selenium/node-firefox:latest
    volumes:
      - /dev/shm:/dev/shm
    depends_on:
      - hub
    environment:
      HUB_HOST: hub

  chrome:
    image: selenium/node-chrome:latest
    volumes:
      - /dev/shm:/dev/shm
    depends_on:
      - hub
    environment:
      HUB_HOST: hub

  hub:
    image: selenium/hub:latest
    ports:
      - "4444:4444"

cite: Selenium Grid via docker-compose

I copied the example docker-compose.yml in the above link for Version 3. Alterations I made were to use a later docker-compose version and to add my testserver service.

For the test server I added the following:

• named the service: testserver
• specified the container is build from .(the current) directory.
• image name is: smashtest-docker
• volume is mapped bi-directionally from the host to the container. This was done for easier development purposes for adding, updating, and deleting any *.smashtest files and smashtest.json configurations.

How-to Run

1. docker-compose down - to ensure nothing is left over.
2. docker-compose build - to build the container
3. docker-compose up -d - Run’s a container with node and smashtest code.
4. docker-compose run --rm testserver npx smashtest - Executes the npx smashtest command against the docker-compose’d container.

How-to Clean-up

NOTE This will delete all containers and images. If you want a more targetted clean up specify each container and image.

1. docker-compose down
2. docker container prune -f
3. docker image prune -f --all

Next Steps

• Docker Swarm Deployment