Building lean Docker images

Hugo
Hugo
Dec 3, 2018 · 3 min read
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Separating build and runtime dependencies

No matter which language you use — whether it’s Node.js, Go, Python, or something else — it’s almost inevitable that you’ll have both build and runtime dependencies.

Consolidating shared dependencies into a base image

If you have more than a few applications sharing the same stack and some of the same dependencies, you can create a base image to reduce total build time. This means that rather than re-installing shared dependencies for every build you can pull the layers in binary form, no compilation/installation required!

docker build --file parent.Dockerfile --tag parent .

Build stages and scratch-based images

This example pertains more to compiled applications. In these cases you can compile your application using one Docker image, and then copy the binary into a scratch image as a single binary. scratch images have no base layers, so they’re super lightweight!


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