In parallel builds where a list of image targets are provided the build
may produce binaries that are not part of the named set of targets but
are created by series dependencies. These implicitly created binaries
may be generated by multiple builds but are unused as our convention for
the ubuntu-cpc project is to only consume binaries from the explicitly
named image targets; this avoid overwriting the same object by multiple
parallel builds.
This patch adds support for a 'provides' keyword for series files. It can
be specified multiple times per series file. The field is used by the
make-hooks script to generate a list of output files created explicitly by
the named image targets. The list is saved to the "explicit_provides"
file in the hooks output directory. In the case of the "all" target
this list would be empty. This list is consumed by the "final.binary"
hook file.
This patch adds support for optional final.binary hooks in hooks.d/base
and/or hooks.d/extra. These final.binary hooks are always included as
the last hook(s) if either exist with the hook in "extra" running last.
The base/final.binary hook includes logic to parse the "explicit_provides"
file generated by the make-hooks script and remove any binary output not
explicitly specified.
Some series files named unnecessary dependencies, specifically
disk-image, to keep output of implicit artifacts consistent between
parallel builds. These unnecessary dependencies are removed in this
patch.
The following targets have livecd.ubuntu-cpc.manifest (and
livecd.ubuntu-cpc.ext4) which differ in some way from the 'all'
target. They are all missing grub-efi and other modifications:
root-dir
squashfs
tarball
These targets do not depend on the 'disk-image' target. This means that
the ext4 produced will lack the uefi modifications (and any from the
disk-image target binary hooks).
Since the ext4 file is common to all builds there is a chance that a
parallel build from one of these targets could overwrite this artifact.
This patch ensures that all targets will produce consistent base output.
An upcoming addition of the disk-image target to several series files will
required some explanation. Without comment support in series files that
is not possible. This patch adds support for comments in series files.
* Replace "snap download" with tool that uses snap store's coherence feature
This is important for parallel image builds to ensure all pre-seeded snaps
have the same versions across image variants.
* Inject a proxy into the build providing a snapshot view of the package repo.
When the REPO_SNAPSHOT_STAMP variable is set, the auto/build script will attempt
to launch a transparent HTTP proxy on port 8080, and insert an iptables rule to
redirect all outgoing HTTP requests to this proxy.
The proxy, contained in the `magic-proxy` Python script, examines each request
and silently overrides those pointing to InRelease files or files that are
listed in InRelease files. It will instead provide the contents of the requested
file as it was at REPO_SNAPSHOT_STAMP, by downloading the corresponding asset
"by hash".
* Use series files with dependency handling to generate hook symlinks dynamically
This patch currently only applies to the "ubuntu-cpc" project.
More and more logic has been going into the hook scripts to decide
under which conditions they should run or not. As we are moving
to parallelized builds of image sets, this will get even more
complicated. Base hooks will have to know which image sets they
belong to and modification of the dependency chain between scripts
will become more complicated and prone to errors, as the number of
image sets grows.
This patch introduces explicit ordering and dependency handling for
scripts through the use of `series` files and an explicit syntax
for dependency specification.
