Safe disable SELinux

Sometimes, a sysadmin might outright delete the SELinux rpms and
delete the configuration. This causes the selinux module to fail
with
```
IOError: [Errno 2] No such file or directory: '/etc/selinux/config'\n",
"module_stdout": "", "msg": "MODULE FAILURE"}
```

This simply checks that /etc/selinux/config exists before we try
to set it Permissive.

Update from feedback

Add graceful upgrade process

Calico does not allow renaming hosts

Fix fact tags

Ansible playbook fails when tags are limited to "facts,etcd" or to
"facts". This patch allows to run ansible-playbook to gather facts only
that don't require calico/flannel/weave components to be verified. This
allows to run ansible with 'facts,bootstrap-os' or just 'facts' to
gether facts that don't require specific components.

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

Mount host's /var/log into kubelet container

Better control instance sizing

Fix references to CoreOS and Container Linux by CoreOS

fix typo in "kibana_base_url" variable name

* Git ignore the user controlled config.rb.
* Ability to better control the number of instances running.

Kubelet is responsible for creating symlinks from /var/lib/docker to /var/log
to make fluentd logging collector work.
However without using host's /var/log those links are invisible to fluentd.

This is done on rkt configuration too.

Fixes #967

This typo lead to kibana_base_url being undefined and Kibana used
default base URL ("/") which is incorrect with default proxy-based
access.

ask confirmation before running reset.yml playbook

Based on #718 introduced by rsmitty.

Includes all roles and all options to support deployment of
new hosts in case they were added to inventory.

Main difference here is that master role is evaluated first
so that master components get upgraded first.

Fixes #694

Change default network plugin to Calico

set "check_mode: on" for read-only "shell" steps that registers result

remove temporary file

Add timings to RECAP output.

- Starting from version 2.0 ansible has 'callback_whitelist =
  profile_tasks'. It allows to analyze CI to find some time regressions.
- Add skippy to CI's ansible.cfg

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

Adding support for proxy w/ rkt kubelet

Update calico to v1.0.2

Disable kube_proxy_masquerade_all

Multiples doc fixes

Install pip on Ubuntu

Replace always_run with check_mode

Set ssl_ca_dirs for rkt based on fact

- Refactor 'Check if bootstrap is needed' as ansible loop. This allows
  to add new elements easily without refactoring. Add pip to the list.
- Refactor 'Install python 2.x' task to run once if any of rc
  codes != 0. Actually, need_bootstrap is array of hashes, so map will
  allow to get single array of rc statuses. So if status is not zero it
  will be sorted and the last element will be get, converted to bool.

Closes: #961
Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

Install pip on Ubuntu