Docker Workshop - Docker Best Practices
Sections:
Best practices for writing Dockerfiles
Best Practices for Dockerfiles Documentation
Containers should be ephemeral
- The container produced by the image your Dockerfile defines should be as ephemeral as possible.
- By “ephemeral,” we mean that it can be stopped and destroyed and a new one built and put in place with an absolute minimum of set-up and configuration.
Use a .dockerignore file
- In most cases, it’s best to put each Dockerfile in an empty directory.
- Then, add to that directory only the files needed for building the Dockerfile.
- To increase the build’s performance, you can exclude files and directories by adding a .dockerignore file to that directory as well.
Avoid installing unnecessary packages
- In order to reduce complexity, dependencies, file sizes, and build times, you should avoid installing extra or unnecessary packages just because they might be “nice to have.”
Each container should have only one concern
- Decoupling applications into multiple containers makes it much easier to scale horizontally and reuse containers
Minimize the number of layers
- You need to find the balance between readability (and thus long-term maintainability) of the Dockerfile and minimizing the number of layers it uses.
- Be strategic and cautious about the number of layers you use.
Sort multi-line arguments
- Whenever possible, ease later changes by sorting multi-line arguments alphanumerically.
- This will help you avoid duplication of packages and make the list much easier to update.
- This also makes PRs a lot easier to read and review
RUN apt-get update && apt-get install -y \
bzr \
cvs \
git \
mercurial \
subversion
Try to run all the RUN COMMANDS in one line because doing multiple RUN commands makes image larger
Read Best Practices README
Github user FuriKuri wrote an excellent README compiling best practices from blogs and other articles HERE
Bread Crumb Navigation
| Previous | Next |
|---|---|
| ← Continuous Integration | README → |