* Vagrantfile: Bump openSUSE to Leap 15.0

* roles: container-engine: Add 'containerd' package for openSUSE

The 'containerd' package contains the docker-containerd and
docker-containerd-shim binaries. We also need to ensure that the latest
version is installed since an older version may already be present (eg GCE
images)

* Remove docker log-opts for opensuse

* roles: bootstrap-os: Use lowercase 'o' for openSUSE

OpenSUSE is not a valid family name. The correct one is openSUSE

* roles: bootstrap-os: Update zypper cache before first installation

The zypper cache may be outdated so ensure that it's fully updated
before we try and install the bootstrap packages.

* robust handling of API server SANs

* use apiserver_loadbalancer_domain_name if it is defined, according to PR 3977

* Run terraform fmt

* Add terraform fmt to .terraform-validate CI step

* Add tf-validate-aws CI step

* Revert "Add tf-validate-aws CI step"

This reverts commit e007225fac831d263613ae9ab2998d11c3e8673d.

The iteritems() dictionary's method has been removed in Python3. Using
this method in Jinja2 templates limits the execution to Python2 which
will be deprecated in 2020[1]. This change replaces that method for
the items() method as it's suggested in the official website[2].

[1] https://pythonclock.org/
[2] https://docs.ansible.com/ansible/latest/user_guide/playbooks_python_version.html#dict-iteritems

* Update premoderator to fix Github API throttle

* Update premoderator script

Add exit codes and document the exit code.

* Fix indentation

The .terraform directory is populated when modules are downloaded:
https://www.terraform.io/docs/commands/get.html
"The modules are downloaded into a local .terraform folder. This folder should not be committed to version control."

* Update CoreDNS to 1.4.0

* Update readme to reflect CoreDNS update

* Update DNS Autoscaler

* Update downloads too

* Fix yamllint

* Fix yamllint

* enable kubelet client certificate rotation

* change to variable kubelet_rotate_certificates

Both the `yum` and `apt` modules support a list as input, this allows us avoid the slower `with_items` approach, which can take a long time with a large count of cluster nodes.

Both kubedns and dnsmasq modes are long not maintained.
We should run dns_late steps at the end because sshd
makes DNS lookups during Ansible run and has 2s timeouts
for each failed lookup trying to connect to coredns before
it is ready.

* Lint everything in the repository with yamllint

* yamllint fixes: syntax fixes only

* yamllint fixes: move comments to play names

* yamllint fixes: indent comments in .gitlab-ci.yml file

* Fix jinja2 boolean condition

* Convert all felix variable to booleans instead.

The correct name is Packet, not Packet Host.

This commit adapts the "Lay Down KubeDNS Template" task to use the static
files moved by pull request [1]

[1] https://github.com/kubernetes-sigs/kubespray/pull/4341

* Fix bootsrap-os role, failing to create remote_tmp

* use ansible_remote_tmp hostvar