Fix kubeadm config images pull

Supported by kubeadm v1.11

Without this pods cannot communicate with each other by default (broken
networking)

Closes #2114

* Fix random failure in debug: var=result.content|from_json

* netchecker agents are deployed on all k8s-cluster group members

* reducing limits/requests is not enough, switching to n1-standard-2

* gce_centos7 need more cpu

Introduce `calico_upgrade_url` var for Calico upgrade tool.

So that binary can be sourced from anywhere - not only github.

Fix epel_enabled and RHEL support in bootstrap-os

Looks like `epel_enabled` was not configured for the epel install in `bootstrap-centos.yml`. Also, there were no conditionals that would trigger bootstrap for RHEL.

Fix docker 18.09.1 systemd service

The `docker-ce` 18.09.1 packaging missed an `After` dependency on containerd in the systemd service. Upstream PR: https://github.com/docker/docker-ce-packaging/pull/290

* Use external LB IP for external api endpoint

Use loadbalancer_apiserver.address instead of apiserver_loadbalancer_domain_name for kudadm init --apiserver-advertise-address argument

https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm-init/#options states apiserver-advertise-address needs to be a IPv4 or IPv6 address

* only use loadbalancer IP if it is defined

Fix PATH for kubeadm init

Update helm version for security and stablity fixes

Bump docker 18.09 to the latest patch

Helm v2.12.2 has fixes for a security vuln, and there have been several improvements since our last update.

* Generate external admin.conf with kubeadm

* Fix apiserver sans

[calico/canal] mount host's xtables lock and enable calico locking for <v3.2.1

Docker 18.09.1 is out and it includes some fixes that are quite critical for RHEL distros, details here: https://docs.docker.com/engine/release-notes/#18091

Fix kubeadm config extra volumes

I found a potential use case where `writable` could be null and therfore
not treated like a boolean, so this adds an extra default statement to
avoid negating a non-boolean as boolean which would lead to undefined. refs #4020

Fix local-volume-provisioner configmap template

fix registry_storage_class equals empty string

Use --bind-address instead of --address

Add image builder to create Docker vm's for kube-virt

Update kubectl and etcd download urls for mult-arch

Looks like the template is removing the trailing space between storage
class entries, and since CI only has one storage class we never hit this
issue. This change will prevent the yaml from printing on a single line
when multiple storage classes are defined.

Use Pypy portable on coreos

Upgrade kubernetes to v1.13.2

--address deprecated

Fix readOnly flag in kubeadm-config.v1beta1.yaml.j2