Add tiny and small build images

[maribu]

Add tiny build images

This adds Alpine based images intended for use with

make BUILD_IN_DOCKER=1 DOCKER_IMAGE=docker.io/riot/tinybuild-<ARCH>

This adds the following images:

• tinybuild-native64: C toolchain needed to build RIOT apps for native64
• smallbuild-native64: C, C++, and rust toolchain needed to build RIOT apps for native64
• tinybuild-arm: C toolchain needed to build RIOT apps for ARM7 & ARM Cortex M boards
• smallbuild-arm: C, C++ and rust toolchain libc needed to build RIOT apps for ARM7 & ARM Cortex M boards
• tinybuild-avr: C and C++ toolchain and AVR libc needed to build RIOT apps for AVR boards
• tinybuild-msp430: C toolchain needed to build RIOT apps for MSP430 boards
• smallbuild-msp430: C and C++ toolchain needed to build RIOT apps for MSP430 boards
• tinybuild-risc-v: C toolchain needed to build RIOT apps for RISC-V boards
• smallbuild-risc-v: C, C++, and rust toolchain needed to build RIOT apps for RISC-V boards

For comparison, this is the size:

REPOSITORY                            TAG         IMAGE ID      CREATED            SIZE
docker.io/riot/riotbuild              latest      138e78010e19  4 weeks ago        13.5 GB
localhost/maribu/smallbuild-arm       latest      1fb5420486b7  56 minutes ago     4.23 GB
localhost/maribu/smallbuild-base      latest      a56817ee290e  59 minutes ago     1.74 GB
localhost/maribu/smallbuild-msp430    latest      11e2ecc41466  36 minutes ago     452 MB
localhost/maribu/smallbuild-native64  latest      86a4a333ac44  48 minutes ago     2.39 GB
localhost/maribu/smallbuild-risc-v    latest      a4692906f483  39 minutes ago     3.28 GB
localhost/maribu/tinybuild-arm        latest      d3718b8a6b57  58 minutes ago     1.17 GB
localhost/maribu/tinybuild-avr        latest      41013f963ddc  37 minutes ago     405 MB
localhost/maribu/tinybuild-base       latest      bd9802e90d98  About an hour ago  62.7 MB
localhost/maribu/tinybuild-msp430     latest      9f2c69543069  36 minutes ago     342 MB
localhost/maribu/tinybuild-native64   latest      6d01bf6ebece  51 minutes ago     239 MB
localhost/maribu/tinybuild-risc-v     latest      97066835a715  37 minutes ago     1.06 GB

I tested to build examples/basic/default for one board with each docker image successfully.

[mguetschow]

Nice!

Any thoughts already on how we could integrate this into our CI? Having separate docker images is certainly less straightforward. But even summing all of them up into a single container would end up with way less than what we currently have (maybe also just because some tools for, e.g., static tests are not included?). In any case I'd prefer not having both the old debian-based container and the new alpine-based container(s) around in the future to avoid confusion. What would be currently still missing to do the switch?

Or are those mostly meant to be used for local development instead of CI?

[maribu]

A single container that would contain all listed toolchains is very much possible and ends up being about 2 GiB. I can also add the tools needed for static tests. I think we would end up with about 2.5 GiB then.

However, this will not be able to replace the current image:

1. There are no ESP toolchains packaged for Alpine. Using the prebuild magic Espressif toolchain with the glibc compat package installed might be OKish. Better would be to just package the Espressif Toolchain. I have spent 2 weeks on that and ended up with a toolchain that worked for the bootloader, but not for RIOT apps.
2. Alpine has no multilib support. An x86_64 container only supports native64 and not native32.
3. There are still bugs in native* on musl that need to be fixed. This is probably the easiest of the three.

So from the RIOT's PoV, those images will probably remain a local option for users to use with BUILD_IN_DOCKER=1.

That said, using them in a CI is for downstream projects highly interesting. The typical downstream project consists of one (or a few) boards, one (or a few) modules, and a RIOT git submodule. E.g. my business card project could very much make use of the tinybuild-arm container for a CI. (The project I intend to use this for is a bit more complex and larger, but has a somewhat similar architecture.)

I have some interest in maintaining small containers capable for powering the CI of a downstream project that only needs to build for a single arch.