GitHub docker testing

[ShahanaFarooqui]

• Temporarily adding rc tag trigger, some input variables & more logs for testing Build and push multi-platform docker images action flow before the final release.

• Poetry on arm32: The Docker build for linux/arm/v7 failed in recent RC releases on the Poetry installation step in the builder-python stage. This issue occurred because the builder-python stage builds on target's arch but poetry was unable to install on arm/v7 without rust >= v1.56.1.

  • Solution: Instead of installing poetry on the builder-python stage, we leveraged the existing multi-arch builder stage, which already had Poetry. Now, we export the dependencies from pyproject.toml to requirements.txt within the builder stage and then copy requirements.txt to the builder-python stage for pip installation.

• Cryptography installation: python installations for pyln-proto started failing due to Cryptography upgrade from v41 to v42 (PR pyln-proto: update cryptography to v42 #7475). It is because now Cryptography needs cargo/rust also.

  • Solution: Installing cargo in builder-python stage also.

• Configure Prefix: Previously, we used RUN ./configure --prefix=/tmp/lightning_install --enable-static in the builder image and then copied /tmp/lightning_install from the builder stage to /usr/local in the final stage. However, this approach is now causing errors due to missing binaries/plugins at their default locations.

  • Solution: We are now configuring the installation to use the default location (/usr/local). To prevent the local image size from increasing by up to 87MB, instead of copying the entire /usr/local/ directory, we are explicitly copying only the core lightning binaries.

Changelog-Fixed: Fixes failing Docker build for arm32 arch.

[cdecker]

ACK 167e91e

Just a minor discrepancy between envvars and their documentation (push defaults to true, rather than false as the docs claim).