Dotnet-docker: [Feature request] A smaller runtime image

[tuananh]

Reference: https://github.com/dotnet/dotnet-docker/pull/309

[MichaelSimons]

@richlander - thoughts? I've heard no other asks for a slimmer Debian image. All asks have been for alpine.

[mahald]

i think anyone is interested in smaller images (at least me is), as alpine usually is the smallest (2MB !!) people ask for alpine.
ist there any reason not to use
debian:stretch-slim (also official) ?
stretch-slim is 22 MB (compressed in the registry) while stretch is 45MB while alpine is 2 MB.
im currently dling ur dockerfiles for stretch and change it to stretch-slim to get a smaller image. And all is still working fine.

[mahald]

PS: debian:strech-slim is also as small (both 22MB in the registry) as this bitnami stretch, so it migth be better to use the official debian:stretch-slim. Note: for the dev image it doesn't really matter, but for the runtime image the slim variant is desired. and i don't see any disatvantage in using it (at least not for the runtime).

On the other hand if alpine is comming out and if it runs as stable as debian i gonna use apline due to it's small size and don't care for stretch anymore.

[richlander]

Alpine support is coming soon, meaning 2017.

[AnthonyMastrean]

@richlander Hi, from 2018! Which issues/PRs should we follow for updates? Are we generally just waiting on .NET Core 2.1 release? Until then, thank you!

@MichaelSimons I would love to avoid maintaining my own custom Debian slim image. The only change is in the FROM line 😄

-FROM debian:stretch
+FROM debian:stretch-slim

https://github.com/dotnet/dotnet-docker/blob/master/2.0/runtime-deps/stretch/amd64/Dockerfile#L1

Of course, the Alpine image the superior solution for managing image size, that's probably why it's most requested.

[MichaelSimons]

@AnthonyMastrean - 2.1-preview1 images are available today. This includes the Alpine images as well as debian-slim and ubuntu ~-slim~ based runtime images. Ubuntu was chosen as it is generally more secure (e.g. has fewer vulnerabilities) than Debian.

Regarding your suggestion of changing the 2.0 images to be based on stretch-slim, we would not be able to make a change like this as it would be considered a breaking change.

[AnthonyMastrean]

@MichaelSimons I'll wait for the .NET Core 2.1 GA. I have some older apps running on .NET Core 1.1 LTS for the forseeable future. I guess I'll just maintain my custom base images! If it's not too complicated to explain, why is a slim image considered breaking? What if it's provided _in addition_ to the regular image?

[MichaelSimons]

@AnthonyMastrean - Changing the existing images to slim is considered breaking as users can have dependencies on the components/files that were removed within the slim image. An additional image would be the way to add support.

[richlander]

I think we can close this now ... We're not going to change the base image of the 2.0 images and the 2.1 images have a solution. Good?

[MichaelSimons]

Hearing no objection on the new distros for the 2.1 images, I'm closing this. We always welcome feedback on distros we produce images for.