When this happens in travis the intermediate images
aren't pushed, so you have to rebuild locally.
The dockerdiff output may be large, but that's more useful
than having to try and reproduce locally.
Tweak the tests so that they use default-mysql-server
on newer dists as it replaced the mysql-server package.
Also add explicit import of the buster signing key
as the Travis agent doesn't have it available.
Thanks to Filippo Giunchedi (@filippog) for the initial
work on this.
Change the mkimage script so that the produced image is
reproducible. This involves:
- removing the ldconfig aux-cache as it changes on every build.
- set the mtimes of the files to a specific date so that the
resulting tar file will have the same contents.
- The `strings` guard around the unsafe-io tweak seems to be
non-deterministic. It was sometimes not adding the tweak
for the same file. Remove it as we don't care about older
than jessie.
- Importing the image by constructing a docker image with
a specific timestamp and doing `docker load`.
Also change the buildall script to build each image twice and
confirm that the same tarball is produced, and that results
in the layers in the imported images matching.
Add a dockerdiff script that checks that two images are equivalent,
and tries to show the differences if not. This is useful when the
build script reports differences, as it can point to what the
differences are.
Carlos Rodríguez Hernández