Add etcd-events cluster for kube-apiserver

import_tasks will consume far less memory, so it should be
used whenever it is compatible.

This reverts commit 4209f1cb.

* Security fixes for etcd

* Use certs when querying etcd

* 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

etcd is crucial part of kubernetes cluster. Ansible restarts etcd on
reconfiguration. Backup helps operator to restore cluster manually in
case of any issues.

Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

Migrate older inline= syntax to pure yml syntax for module args as to be consistant with most of the rest of the tasks
Cleanup some spacing in various files
Rename some files named yaml to yml for consistancy

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

in the etcd handler, the reload etcd action
was called after ansible waits for etcd to be
up, this means that the health checks which are
called immediately after fail (resulting in the etcd
role always failing and never finishing)

This patch changes the order to move the 'wait for etcd
up' resource after the 'reload etcd resource', ensuring that
the service is up before the health check is called.

Changed Wants=docker.service to docker.socket

Renamed handlers for reloading systemd to contain role in task name.

etcd facts are generated in kubernetes/preinstall, so etcd nodes need
to be evaluated first before the rest of the deployment.

Moved several directory facts from kubernetes/node to
kubernetes/preinstall because they are not backward dependent.

Improved docker reload command to wait for etcd to be
up before proceeding. Switched reload to run restart
because it can't reload if it is not guaranteed to be
in running state.

* Enforce a etcd-proxy role to a k8s-cluster group members. This
provides an HA layout for all of the k8s cluster internal clients.
* Proxies to be run on each node in the group as a separate etcd
instances with a readwrite proxy mode and listen the given endpoint,
which is either the access_ip:2379 or the localhost:2379.
* A notion for the 'kube_etcd_multiaccess' is: ignore endpoints and
loadbalancers and use the etcd members IPs as a comma-separated
list. Otherwise, clients shall use the local endpoint provided by a
etcd-proxy instances on each etcd node. A Netwroking plugins always
use that access mode.
* Fix apiserver's etcd servers args to use the etcd_access_endpoint.
* Fix networking plugins flannel/calico to use the etcd_endpoint.
* Fix name env var for non masters to be set as well.
* Fix etcd_client_url was not used anywhere and other etcd_* facts
evaluation was duplicated in a few places.
* Define proxy modes only in the env file, if not a master. Del
an automatic proxy mode decisions for etcd nodes in init/unit scripts.
* Use Wants= instead of Requires= as "This is the recommended way to
hook start-up of one unit to the start-up of another unit"
* Make apiserver/calico Wants= etcd-proxy to keep it always up

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Co-authored-by: Matthew Mosesohn <mmosesohn@mirantis.com>

Running etcd in Docker reduces the number of individual file
downloads and services running on the host.

Note: etcd container v3.0.1 moves bindir to /usr/local/bin

Fixes: #298

fix etcd configuration for nodes

fix wrong calico checksums

using a var name etcd_bin_dir

fix etcd handlers for sysvinit

using a var name etcd_bin_dir

sysvinit script

review etcd configuration