* Defaults for apiserver_loadbalancer_domain_name

When loadbalancer_apiserver is defined, use the
apiserver_loadbalancer_domain_name with a given default value.

Fix unconsistencies for checking if apiserver_loadbalancer_domain_name
is defined AND using it with a default value provided at once.

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

* Define defaults for LB modes in common defaults

Adjust the defaults for apiserver_loadbalancer_domain_name and
loadbalancer_apiserver_localhost to come from a single source, which is
kubespray-defaults. Removes some confusion and simplefies the code.

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

* Refactor downloads to use download role directly

Also disable fact delegation so download delegate works acros OSes.

* clean up bools and ansible_os_family conditionals

In 1.8, the Node authorization mode should be listed first to
allow kubelet to access secrets. This seems to only impact
environments with cloudprovider enabled.

* add istio addon

* add addons to a ci job

* Rename dns_server to dnsmasq_dns_server so that it includes role prefix
as the var name is generic and conflicts when integrating with existing ansible automation.
*  Enable selinux state to be configurable with new var preinstall_selinux_state

* Set no_proxy to all local ips

* Use proxy settings on all necessary tasks

* Upgrade to kubernetes v1.8.0

hyperkube no longer contains rsync, so now use cp

* Enable node authorization mode

* change kube-proxy cert group name

These facts can be generated in defaults with a performance
boost.

Also cleaned up duplicate etcd var names.

Also fix yaml lint issues

Fixes #1703

New files: /etc/kubernetes/admin.conf
           /root/.kube/config
           $GITDIR/artifacts/{kubectl,admin.conf}

Optional method to download kubectl and admin.conf if
kubeconfig_lcoalhost is set to true (default false)

- Enable Cinder API version for block storage
- Enable floating IP for LBaaS

* kubeadm support

* move k8s master to a subtask
* disable k8s secrets when using kubeadm
* fix etcd cert serial var
* move simple auth users to master role
* make a kubeadm-specific env file for kubelet
* add non-ha CI job

* change ci boolean vars to json format

* fixup

* Update create-gce.yml

* Update create-gce.yml

* Update create-gce.yml

Removed unnecessary root user

  * using separated vault roles for generate certs with different `O` (Organization) subject field;
  * configure vault roles for issuing certificates with different `CN` (Common name) subject field;
  * set `CN` and `O` to `kubernetes` and `etcd` certificates;
  * vault/defaults vars definition was simplified;
  * vault dirs variables defined in kubernetes-defaults foles for using
  shared tasks in etcd and kubernetes/secrets roles;
  * upgrade vault to 0.8.1;
  * generate random vault user password for each role by default;
  * fix `serial` file name for vault certs;
  * move vault auth request to issue_cert tasks;
  * enable `RBAC` in vault CI;

* Adding yaml linter to ci check

* Minor linting fixes from yamllint

* Changing CI to install python pkgs from requirements.txt

- adding in a secondary requirements.txt for tests
- moving yamllint to tests requirements