Docker

Install on Linux

# Docker install
sudo apt update
sudo apt install --yes docker.io
sudo systemctl start docker
sudo usermod -aG docker $USER
su - $USER # it may just be easier to reboot at this point
docker run hello-world

Play with Docker

• https://labs.play-with-docker.com/

Commands

# Run image and jump into it
docker run -it gcc

# Remove all images
docker images -q | xargs docker rmi --force

# Or... much nicer
docker system prune <<< y

Streamlining your images

apt clean distclean autoclean autoremove

Optimising container sizes

• Use Alpine version of base container
• Stable layers go at the top
• Make use of .dockerignore (check how much is transferred to build context)
• Consolidate series of commands that install and remove artifacts: previous layers are immutable
• Use multi-stage containers to copy only build assets into final container

Tools

• dive
• slim

See https://www.youtube.com/watch?v=t779DVjCKC