This implements the proposal in #2564 and converts a handful of representative
or especially interesting (from a build PoV) packages to use it.
For now those pkg/* affected get a stub-`Makefile`, once all packages are
converted then `pkg/Makefile` can be adjusted and those stubs can be removed.
For now only `pkg/package.mk`'s functionality is implemented. In particular:
- `push-manifest.sh` remains a separate script, to enable calling it on systems
with just the LinuxKit tools installed arrange to install it under a less
generic name.
- `kernel` and `tools/alpine` do not use `pkg/package.mk` and those cases are
not yet fully considered/covered.
I have updated the documentation assuming that the existing uses of
`pkg/package.mk` will be removed quite soon in a follow up PR rather than
trying to document the situation which results after just this commit.
Due to `cmd/linuxkit` now gaining a library the build needs adjusting slightly to
allow both `make bin/linuxkit` and `go build` to work.
`go vet` has forced me to write some rather asinine comments for things that
are rather obvious from the name.
Signed-off-by: Ian Campbell <ijc@docker.com>
This updates the build of the two image caches to use the `pkg/package.mk`
infrastructure, albeit in a slightly (ok, very) atypical way.
In order to share the bulk of the build code (including the `Dockerfile` and
the `Makefile` machinery to download the images) we arrange for the necessary
bits to be copied at build time into distinct subdirectories and for the
`pkg/package.mk` to be aware of this possibility.
Since pkg/package.mk is only set up to build a single package we use a single
`image-cache/Makefile` to drive the whole process and recurse into
`Makefile.pkg` to build individual packages.
One particular subtlety is that the package hash is based on the `image-cache`
directory (which is in `git`) rather than the generated subdirectories (which
are not in `git`). Since all the generators (and their inputs) are in the
`image-cache` directory this is what we want. This means that the two images
are given the same tag, but this is deliberate and desirable.
The generated directories are completely temporary to avoid picking up stale
versions of images when versions are updated. Images are hardlinked into place.
The images are moved to the linuxkitprojects org. Using a dev tag for now, will
update once everything is in place.
Also use "tag" rather than "build" where appropriate in the Makefile.
There is no point in the .dockerignore now, but add a .gitignore.
Signed-off-by: Ian Campbell <ijc@docker.com>
