Docker · 12-day planAll days
Day 9 of 12 30 minENV & ARGSecretsUSER
Build one image and run it anywhere by configuring it from outside. Use environment variables, env files, ENV and build-time ARG, keep secrets out of images, run as a normal user instead of root, and limit memory and CPU.
By the end of today you can
- Configure containers with -e and --env-file instead of rebuilding
- Set defaults with ENV and build-time values with ARG
- Explain why secrets must never go in a Dockerfile or image
- Run containers as a non-root user with USER
- Limit a container's memory and CPU
What's inside
- 5 sections
- 2 diagrams and mind maps
- 6 code examples you can run
- 5-question quiz
- 1Same image, different settings
- 2ENV and ARG in the Dockerfile
- 3Secrets don't belong in images
- 4Don't run as root
- 5Limiting resources
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