GitLab

We don't have any ARM64 CI Runner at this time.

Also sort "VENDOR-VERSION-ARCH" variables.

This reverts commit d1c81e86.

krb5 1.18.2 was promoted to the "updates" repository.

Fedora's 'updates-testing' repository has fixed version of the krb5
package. Lets install it for the sake of 'tsiggss' and 'nsupdate'
system tests.

Also drop other (unused) Linux distributions.

Pointing to repos in $(CENTOS_MIRROR_BASE_URL)/7/ namespace means using
always the latest CentOS 7 repos (7.8 at this point), even if the install
ISO was CentOS 7.7. A more version-specific repos should be used during
the installation.

Current backtraces from cores produced by system tests miss a lot
information on Alpine Linux. Adding the 'musl-dbg' package makes them on
par with the rest of C libraries. Addition size is about 3 MB.

The combination of current CentOS/EPEL 7 versions of mock and GPGME
triggers the following error when YUM invoked by mock running in a
Docker container attempts to verify repository metadata:

    gpgme.GpgmeError: (7, 32870, u'Inappropriate ioctl for device')

This prevents any CentOS 7 RPM packages from being built in GitLab CI.
Work around the problem by forcing mock to run YUM without a PTY
attached.

YUM for CentOS 6 does not support the "ip_resolve" configuration option,
so the tweaks applied in the Dockerfile are not fully effective.
Furthermore, hardcoded file paths make those tweaks prone to breaking
due to package updates.  It is also simpler to disable IPv6 globally
after creating a Docker container than trying to patch all places where
it can potentially be used at image build time.

The "tzdata" Ubuntu package is no longer a dependency of any of the
packages we install on that system.  Make sure it always gets installed
by explicitly including it in the list of packages to install on
Debian/Ubuntu, so that the "time_test" BIND unit test can pass.

As we plan to at least update the Python QA tools used for BIND in
GitLab CI after each BIND release goes public, add Debian buster to the
list of operating system whose images are rebuilt on a monthly basis to
make sure any potential issues caused by OS updates are caught in due
time.

With the introduction of Python-based system tests in BIND, all
operating system images used in GitLab CI should now have pytest and the
"requests" module installed.  Additionally, the pip tool should also be
available to facilitate prototyping tests in merge requests by
eliminating the need to install pip in each CI job.

Otherwise, "pip install" fails.

One of the dependencies of the Cloudsmith CLI now needs this package.

The python-dnspython package was dropped from Debian "sid" and thus can
no longer be installed on that system.  Since this move is a part of a
larger initiative to remove Python 2 from Debian, there is little sense
in trying to implement Dockerfile workarounds for this specific package.
Instead, remove Python 2 packages from all our Debian Docker images
except the "buster" one (to retain some Python 2 test coverage for BIND
branches other than "master").

docker/bind9/ubuntu-template symlinks to docker/bind9/debian-template,
so GitLab CI will never trigger any Ubuntu jobs automatically unless the
symlink itself changes.  Ensure Ubuntu jobs are triggered when
docker/bind9/debian-template is modified, to reflect actual Dockerfile
dependencies.