This seems to be the only place where we are using wget for
downloading anything - all other places use curl. Thus switch to curl
here too. This also makes the job output much shorter as previously it
was spammed with progress reporting.
Sometimes the modification to stage1 repos is necessary. For example
we will need to update baselayout package in stage1, so we get the
cleaned up handling of PATH and ROOTPATH, which will allow a newer
portage to succeed in calculating dependencies in stage2.
The existing tmpfile logic took care of folders that the ebuild keepdir
directive wanted to exist on the OS. However, files and symlinks were
not created, causing them to be missing if we didn't explicitly modify
the ebuild files in coreos-overlay to use tmpfiles or patching of
paths to be in /usr. We need a logic to provide /etc files from the
current /usr partition without getting stale. This can be done best
with an overlay mount which requires to keep the original /etc files
under /usr.
Move the final /etc folder of the image build to /usr/share/flatcar/etc
to serve as lower layer in the overlay. Also remove any state from the
rootfs to make sure that we don't rely on it when testing our images
before the release. What we get with an overlay mount is essentially a
similar behavior to a 3-way merge because as long as the user didn't
change the files, the old version is replaced with the new version and
as soon as the user did changes, that file is frozen and wins over the
provided old (in case of a rollback) or new versions from /usr. It does
not work on file lines but on whole file contents, yet that is also
what rpm-ostree does to my knowledge. Also, run tmpfiles once and do
the SELinux labeling to prevent files being created in the upperdir
because they were missing in the lowerdir, or because they had missing
SELinux labels.
With PORTDIR and PORTDIR_OVERLAY environment variables being gone as
overrides, setting up a profile for the developer container broke. The
overrides were a hack already, as eselect does not seem to have
support for setting a profile based on repos.conf with repo locations
that are valid only after chrooting into the root directory. So
instead of invoking eselect, we set up the symlink ourselves.
That way we can see a report of what emerge is going to do and the
status of the use flags for the installed packages. The downside is
that we are going to have reports about using deprecated and
unsupported profile in even more places.
Emerge flags are cryptic in general, but short flags even more so, so
expand them. While at it, I noticed some places where bash arrays
could be used, so convert those places too.
