How Docker Helps You Land a Software Tester Job Faster

services:
  db:
    image: postgres:16
    environment:
      POSTGRES_USER: qa
      POSTGRES_PASSWORD: qa
      POSTGRES_DB: shop
    ports: ["5432:5432"]

  app:
    image: yourname/demo-shop:1.2.0   # the version under test
    environment:
      DATABASE_URL: postgresql://qa:qa@db:5432/shop
    ports: ["8080:8080"]
    depends_on: [db]

docker compose up -d          # start app + database
docker compose ps             # check they are running
docker compose logs app       # read app logs for a bug report
docker compose down -v        # stop and remove data (fresh next time)

# Start a browser container first:
# docker run -d -p 4444:4444 --shm-size=2g selenium/standalone-chrome

from selenium import webdriver

opts = webdriver.ChromeOptions()
driver = webdriver.Remote(command_executor="http://localhost:4444/wd/hub", options=opts)
try:
    driver.get("https://www.saucedemo.com/")
    assert "Swag Labs" in driver.title
finally:
    driver.quit()

FROM python:3.12-slim
WORKDIR /tests
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt
COPY . .
CMD ["pytest", "-q", "--html=reports/report.html", "--self-contained-html"]

# Build and run (reports saved to your machine):
# docker build -t qa-suite .
# docker run --rm --network host -v "$PWD/reports:/tests/reports" qa-suite

name: ui-tests
on: [pull_request]
jobs:
  test:
    runs-on: ubuntu-latest
    services:
      selenium:
        image: selenium/standalone-chrome
        ports: ["4444:4444"]
        options: --shm-size=2g
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - run: pip install -r requirements.txt
      - run: pytest -q

PROJECT — Containerised UI Test Suite
- Defined app + PostgreSQL test environment with
  Docker Compose for repeatable runs
- Ran Selenium tests against a Chrome container using
  Remote WebDriver; saved HTML reports via volumes
- Executed the suite in GitHub Actions on every PR
github.com/you/docker-qa-lab

Day 1-2  : Install Docker; run hello-world and nginx
Day 3-4  : Images vs containers; ports; logs; exec
Day 5-6  : Compose: app + database
Day 7-8  : Selenium standalone container + Remote WebDriver
Day 9-10 : Dockerfile for your pytest suite
Day 11-12: GitHub Actions with a Selenium service
Day 13-14: README, diagram, resume bullets

docker ps                     # running containers
docker images                 # local images
docker logs -f <name>         # follow logs
docker exec -it <name> sh     # shell inside container
docker compose up -d / down   # start / stop a stack
docker system prune           # clean unused data (careful)

Environment: docker compose (app image demo-shop:1.2.0)
Reproduce:
  1. docker compose up -d
  2. Open http://localhost:8080 and follow steps
Logs: docker compose logs app > app.log (attached)