alt Hacker NewsI don't quite understand how it handles running binaries then. For example, I want to do `bash -c "ls -la /"`. How would it run this command? It needs to assemble the filesystem at this point in the build process.
I guess the answer for Bazel is "don't do this"? Docker handles cross-compilation by using emulators, btw.
> “don’t do this”
Yes. The Bazel way use to produce binaries, files, directories, and then create an image “directly” from these.
Much as you would create a JAR or ZIP or DEB.
This is (1) fast (2) small and (3) more importantly reproducible. Bazel users want their builds to produce artifacts that are exactly the same, for a number of reasons. Size is also nice…do you really need ls and dozens of other executables in your containerized service?
Most Docker users don’t care about reproducibility. They’ll apt-get install and get one version today and another version tomorrow.
Good? Bad? That’s a value judgement. But Bazel users have fundamentally different objectives.
> emulators
Yeah emulators is the Docker solution for producing images of different architectures.
Since Bazel doesn’t run commands as a running container, it skips that consideration entirely.