This RFC proposes that we move all Paketo buildpacks to use direct process types and exec.d interface instead of profile.d interface and direct = false process types wherever possible without breaking backwards compatibility from an end user perspective.
As of Buildpacks RFC 0093 we plan on removing any shell specific logic from the lifecycle and instead have non-shell specific interfaces. In preperation for these changes, we should identify all Paketo buildpacks that rely on profile.d interface or use direct = false process types and convert them to exec.d interfaces and direct = true process types respectively.
direct = false process types and profile.d interfaces have various drawbacks.
- They are slower since they involve shell invocations
- The argument parsing logic can be confusing
- If a process is run with
direct = trueany and allprofile.dscripts are NOT executed potentially causing issues and confusion around the behaviour of the final application image.
Because of all of the reasons above and others listed in Buildpacks RFC 0093, we should try to move away from any shell specific interfaces.
Rationale per above.
Alternatives - keep using shell specific interfaces until they are deprecated.
The migration path should be relatively easy and most profile.d scripts can be easily turned into exec.d scripts. Some more details can be found here
- Most libpak based buildpacks already use exec.d interfaces and
direct = trueprocess types.