Change-Id: I7b998b34881084a68669dc9351ea1937c61534fa

This patch add a way to choose container engine inside tool and test
scripts. This is in preparation for Podman introduction but still
leaves Docker as default container engine.

Signed-off-by: Martin Hiner <m.hiner@partner.samsung.com>
Change-Id: I395d2bdb0dfb4b325b6ad197c8893c8a0f768324

Related-Bug: #1941982
Change-Id: I0e03db1177931ee6d17b21f614573575c3493eef

If we don't set it, then Zun chooses one randomly (the first one
from Neutron).
This may break if it is a network that is not available on
target hosts, e.g. external via L3 agent router.

Since capsules do not support nets yet [1], this patch ensures
desired network creation order in init-runonce instead.

[1] https://bugs.launchpad.net/zun/+bug/1895263

Change-Id: Iaa113dcfb826164a2772d2c91d34ec0236be0817

Zun has a new component "zun-cni-daemon" which should be
deployed in every compute nodes. It is basically an implementation
of CNI (Container Network Interface) that performs the neutron
port binding.

If users is using the capsule (pod) API, the recommended deployment
option is using "cri" as capsule driver. This is basically to use
a CRI runtime (i.e. CRI plugin for containerd) for supporting
capsules (pods). A CRI runtime needs a CNI plugin which is what
the "zun-cni-daemon" provides.

The configuration is based on the Zun installation guide [1].
It consits of the following steps:
* Configure the containerd daemon in the host. The "zun-compute"
  container will use grpc to communicate with this service.
* Install the "zun-cni" binary at host. The containerd process
  will invoke this binary to call the CNI plugin.
* Run a "zun-cni-daemon" container. The "zun-cni" binary will
  communicate with this container via HTTP.

Relevant patches:
Blueprint: https://blueprints.launchpad.net/zun/+spec/add-support-cri-runtime
Install guide: https://review.opendev.org/#/c/707948/
Devstack plugin: https://review.opendev.org/#/c/705338/
Kolla image: https://review.opendev.org/#/c/708273/

[1] https://docs.openstack.org/zun/latest/install/index.html

Depends-On: https://review.opendev.org/#/c/721044/
Change-Id: I9c361a99b355af27907cf80f5c88d97191193495

Co-authored-by: Radosław Piliszek <radoslaw.piliszek@gmail.com>
Depends-on: https://review.opendev.org/694476
Change-Id: I6e7f2f4229c8b579dcc17dacffeb74160875ae29

We fail randomly on check-failure.sh which checks for
containers being down.
Since we share Docker with Zun, the script sees Zun test container
and may fail when it is stopped but not yet removed.

Change-Id: If8b001f7507663e49e8e535f1889592e5f428ab5
Closes-bug: #1853452

- Test Zun on CentOS too
- Make etcd change also trigger Zun jobs (like kuryr and zun)
- Test multinode Zun deployments instead of AIO
  (more likely to break)
- In Zun scenario, stop configuring docker for legacy swarm mode
  (Zun is no swarm)
- Separate test-zun.sh testing script
- Show appcontainer to see which node it has been started on

Change-Id: I289b1009fe00aedb9b78cbd83298b14da5fd9670
Depends-On: https://review.opendev.org/676736


Signed-off-by: Radosław Piliszek <radoslaw.piliszek@gmail.com>