By default do not allow "unqualified" (without a registry) images
because it is considered unsecure and subject to mitm attacks.

To enable insecure pull configure for example:

crio_registries:
  - "docker.io"
  - "quay.io"

Signed-off-by: Victor Morales <v.morales@samsung.com>

* log level by default increased to 'info'
* cgroup manager by default set to 'systemd'
* stream port (used by kubelet) bound to 127.0.0.1 for security reasons
* metrics can be enabled and port specified

* Moved docker_dns_options to defaults so it can be overridden

* Fixed yaml indentation and markdown

* Moved docker_dns_search_domains to defaults

* Enable fedora modular repos for fcos #6299

* Fixed fedora modular repos activation for fcos #6300

CI job 624031102 failed with:

fatal: [ubuntu1804]: FAILED! => {"changed": false, "msg": "Failed to download key at https://download.opensuse.org/repositories/devel:kubic:libcontainers:stable/xUbuntu_18.04/Release.key

: Request failed: <urlopen error [Errno -3] Temporary failure in name resolution>"}

Assuming its a temporary problem it should get more robust with a
couple of retries like in other roles.

Co-authored-by: Hans Feldt <hafe@users.noreply.github.com>

* Install Kata Containers as additional container runtime

* Create RuntimeClasses for Kata Containers

* Updated Vagrant to optionally run without Docker as container manager

* Updated Vagrant to optionally use Libvirt nested virtualization

* Add Kata Containers documentation

* Fix lint errors

* Add kata_containers_enabled to kubespray-defaults

* Fixed typo error

* Fixed typo error

* Manage containerd.io package with docker CRI.

* Refactor common containerd stuff to separate role

* Fix check mode and unnecessary shell.

* fix CRI-O repos for centos distributions

* fix CRI-O repos for centos distributions
- revert workarounds

* fix CRI-O repos for centos distributions
- use https for centos repos

* avoid 302 redirects for centos repos

* Update containerd package to 1.2.13-3.2.el7

* Update Fedora containerd package versions.

* Update Redhat containerd stable and edge packages.

* replace removed repo with kubic repository for centos 7

* add crio configuration for centos8

* add crio configurations for debian

* use correct crio version for fedora

* simplify calulation of required crio version
- gives possibility to overwrite

* change default path for runc

* change default for seccomp path

* change default for conmon

* declare kubic repo for ubuntu

* do not install crictl twice

* move fedora repo modular tasks to crio_repo file

* move centos repo tasks to crio_repo

* declare crio version matrix for ubuntu

* update documentation crio support for ubuntu

* Add proxy support to CRI-O service

The crio.service requires proxy environment variables when it's
deployed behind a corporated network. This change creates a systemd
configuration file when the proxy variables are defined.

* Remove unnecesary crio's tasks

* Add Molecule for container-engine/docker

* Add bootstrap-os to Molecule prepare stage