Getting started with docker + python

Introduction to Docker and showing how well it works with Python app deployments. Docker examples in https://github.com/a-y-khan/python_docker_examples.

Transcript

1. Getting Started With Docker + Python PyLadies SLC, May 2018
2. Docker vs VMs Host OS Hypervisor VM Guest OS ... VM Guest OS Host OS Base OS ... Base OS
3. Docker Image Dockerfile Base OS Dependencies Code Build Image
4. Docker Run Image Run Host OS Base OS
5. Docker Run • docker run -i -t ubuntu:16.04 ◦ interactive example ▪ STDIN open (-i) ▪ pseudo-tty (-t) ◦ Dockerfile command: CMD [“/bin/bash”]
6. Docker Run
7. Docker Run • docker run -it python:3.6 ◦ pulls image from docker repository if needed ◦ run interactively ◦ can also use image ID
8. Docker Run
9. Docker State • Docker images, containers stateless ◦ unless configured otherwise ◦ ephemeral storage • Volume or bind mounting from host OS ◦ persistent storage ◦ separate stateless code from stateful
10. Docker Run With Script • docker run --volume $PWD:/usr/app \ --workdir /usr/app python:3.6 \ python3 hello_world.py ◦ hello_world.py in current working directory
11. Docker Run
12. Docker Build • docker build --tag name:tag PATH | URL ◦ Dockerfile to image ◦ Build context (PATH | URL) ▪ build source ▪ get files from context ▪ size matters! ◦ .dockerignore file
13. Docker CLI Cleanup Commands • docker stop • docker kill • docker rmi ◦ remove images • docker container prune ◦ remove stopped containers
14. Other Docker CLI Commands • docker ps • docker exec • docker history ◦ intermediate images (layers) • docker inspect ◦ container or image metadata https://docs.docker.com/engine/reference/commandline/docker/
15. Docker Compose Network ... https://docs.docker.com/compose/
16. simple_python_docker: python 3 • Build image with Python 3.6 base • docker build -t python3 . ◦ builds python3:latest • docker run python3:latest
17. simple_python_docker: python 2 • Build image with Python 2.7 base • docker build -f Dockerfile.python_27 \ -t python2:demo . ◦ builds python2:demo • docker run python2:demo
18. flask_docker • docker build -t app:1.0 . • docker run \ --publish 5000:5000 \ --name my_app \ --rm \ app:1.0 ◦ Detached mode: --detach
19. flask_docker_logs • docker build -t app:2.0 . • docker run \ --publish 5000:5000 \ --name my_app --rm \ --volume $PWD/logs:/usr/app/logs \ app:2.0
20. ENTRYPOINT vs CMD • ENTRYPOINT ◦ Package specific executable • CMD ◦ Set default parameters, flags ◦ More flexible for executable setting
21. flask_docker-compose • docker-compose build • docker-compose up • docker-compose down
22. flask_multistage_docker-compose • Group image builds in single Dockerfile • Copy artifacts between stages https://docs.docker.com/develop/develop-images/multistage-build