Finding a successor to BPO
At some point it would probably make sense to replace BPO with an off-the-shelf solution.
### Reasons
* More maintainers: Right now I'm maintaining BPO alone and I'm writing almost all of its code, meaning new fixes or features only get developed when I make time for it.
* Getting some important features / improvements, e.g.:
* #146: sign individual packages too, not only the entire APKINDEX
* #149: easier administration
* #57: shorter restart times
* #49: better architecture that doesn't lead to timeouts
* Building packages without network access (maybe unless we have `options="net"` in the APKBUILD, like in Alpine?)
* Alpine is also considering to rebuild their build infra ([tsc#82](https://gitlab.alpinelinux.org/alpine/tsc/-/issues/82)), it would make it a lot easier for us if we ended up using the same software for building the package repository in the end.
### Requirements
* Required: figure out how to build for all foreign architectures we support. Right now we cross compile everything on x86_64 with pmbootstrap. So either we can use pmbootstrap in `$newtool` (through configs / adding a custom build shell script that runs pmbootstrap) or we need to get builders for foreign architectures (which could also be feasible).
* Required: publicly accessible logs for builds, so others can see the failures too and help fixing them
* Required: nice web UI that makes it easy to understand what's going on
* Required: Defer signing to a trusted signer (from Alpine's list)
* Required: Support determining and build batches of packages that depend on each-other (from Alpine's list)
* Required: API hook for triggering builds from our gitlab
* Required: well maintained upstream
* Required: secure architecture, good security practices
* Required: some way to integrate it with our monitoring (could be that we write a small script that calls a bunch of APIs to figure out what jobs failed, so we can send that into the matrix chat via our monitoring)
* Required: some sort of staging repository support (or maybe `home:...` like in openSUSE Build Service)
* Good to have: support building images too? if not we keep bpo around for that for now and only build the packages through the new tool
issue