Container images optimization

[barbararochazup]

Problem

The image containers are too large and it’s necessary to optimize them to avoid security and performance issues. There are some ways to decrease the size of this images:
multi-stage build
image that contains only your application and its runtime dependencies (minimum requirements)

In the last release the sizes of containers images was:

zupcharles/charlescd-circle-matcher:1.0.1 (1.49GB)
zupcharles/charlescd-butler:1.0.1 (424MB)
zupcharles/charlescd-moove:1.0.1 (351MB)
zupcharles/charlescd-villager:1.0.1 (251MB)
zupcharles/charlescd-compass:1.0.1 (84.6MB)
zupcharles/charlescd-ui:1.0.1 (74.8MB)
zupcharles/charlescd-gate:1.0.1 (27.9MB)
zupcharles/charlescd-hermes:1.0.1 (21.6MB)

Expected behavior
A decrease of image size when the image contains only your application and its runtime dependencies (minimum requirements)

Ref

https://docs.docker.com/develop/develop-images/multistage-build/

https://github.com/GoogleContainerTools/distroless

https://www.digitalocean.com/community/tutorials/how-to-optimize-docker-images-for-production (step 5)