The new best practice is to use the RUN --mount cache options. Making the removal of intermediate files unnecessary and speeds up the builds too. Surprised to see so few mentions of it.
As someone whose week was ruined by an overwhelming proliferation of `--mount type=cache` options throughout a complex build system, I'm not so sure.
Externally managed caches don't have a lifecycle controlled or invalidated by changes in Dockerfiles, or by docker cache-purging commands like "system prune".
That means you have to keep track of those caches yourself, which can be a pain in complex, multi-contributor environments with many layers and many builds using the same caches (intentionally or by mistake).
Something roughly equivalent is the medium-term solve, yes. Complicated by the fact that this pattern was used by rather a lot of different folks' code.
hard enough to stay synced with all the latest docker changes, let alone at an organizational level.
Example: in the last few years docker compose files have gone from version 2 to version 3 (missing tons of great v2 features in the name of simplification) to the newest, unnamed unnumbered version which is a merging of versions 2 and 3.
