Download to read offline
Uploaded byAdam Englander
Python and Docker
Docker allows building and running applications in isolated containers using system virtualization instead of full hardware virtualization. It provides advantages like building applications once that can run anywhere, fast versioned deploys, and almost no overhead from virtualization. Docker works by loading a container from an image file with instructions for the runtime environment. Images are built using Dockerfiles that define layers for the file system and can derive from other images. Built images are usually pushed to repositories for version control and deployment.
Python and Docker
- 1.
- 2.
- 3. @adam_englander What is Docker? •A lighter form of Virtual Machines • Utilizes system virtualization instead of full hardware virtualization • Shares same memory and processor • Layered file system for version control and change management • Requires Linux - even Docker for Windows/Mac has Linux VM
- 4. @adam_englander Advantages of Docker •Build Once — Run Everywhere • Commoditization of the Cloud • Super fast versioned deploys and rollbacks • Enables regular and reliable OS patching • Almost no overhead due to virtualization
- 5. @adam_englander How Docker Works •Docker loads a container in memory and runs a command based on the images ENTRYPOINT and CMD values. • That command runs as a foreground process until it exits and which time the container is stopped. • Unless specifically instructed to destroy a container after run, it will persist and be started again with the START command. • Many utilities exist within Docker and without to turn containers into manages services. We will not be discussing those.
- 6. @adam_englander Building an Image •Dockerfile contains instructions for building the image and runtime parameters. Each instruction in order is a layer. • Images may be derivatives of other images and usually should. • Building starts at the first changed layer. • Usually pushed to a repository for version control. • Changes can be tagged.
- 7.
- 8. @adam_englander Resources • https://hub.docker.com/r/library/python/ • https://hub.docker.com/r/aenglander/python-example/ •https://github.com/aenglander/docker-python-example • https://zeit.co/