Fixes #967

- 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>

"shell" step doesn't support check mode, which currently leads to failures,
when Ansible is being run in check mode (because Ansible doesn't run command,
assuming that command might have effect, and no "rc" or "output" is registered).

Setting "check_mode: no" allows to run those "shell" commands in check mode
(which is safe, because those shell commands doesn't have side effects).

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

always_run was deprecated in Ansible 2.2 and will be removed in 2.4
ansible logs contain "[DEPRECATION WARNING]: always_run is deprecated.
Use check_mode = no instead". This patch fix deprecation.

Also calico-cni to v1.5.6, calico-policy to v0.5.2

Fixes: #1011

Since systemd kubelet.service has {{ ssl_ca_dirs }}, fact should be
gathered before writing kubelet.service.

Closes: #1007
Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

Fixes #1012

- Exclude kubelet CPU/RAM (kube-reserved) from cgroup. It decreases a
  chance of overcommitment
- Add a possibility to modify Kubelet node-status-update-frequency
- Add a posibility to configure node-monitor-grace-period,
  node-monitor-period, pod-eviction-timeout for Kubernetes controller
  manager
- Add Kubernetes Relaibility Documentation with recomendations for
  various scenarios.

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

Raise readiness probe initial time to 60 (was 30)

Update code and docs for that assumption.

kubelet lost the ability to load kernel modules.  This
puts that back by adding the lib/modules mount to kubelet.

The new variable kubelet_load_modules can be set to true
to enable this item.  It is OFF by default.

- Since Weave 1.8.x was rewritten in Golang we may decrease RAM settings
  to continue using g1-small for CI

Daemonsets cannot be simply upgraded through a single API call,
regardless of any kubectl documentation. The resource must be
purged and then recreated in order to make any changes.

Also make no-resolv unconditional again. Otherwise, we may end up in
a resolver loop. The resolver loop was the cause for the piling up
parallel queries.

Faster gzip improves CI deploy times by at least 2 mins.

Fixes #982

Fixes upgrade from pre-individual node cert envs.

Reduce election timeout to 5000ms (was 10000ms)
Raise heartbeat interval to 250ms (was 100ms)
Remove etcd cpu share (was 300)
Make etcd_cpu_limit and etcd_memory_limit optional.

Netchecker is rewritten in Go lang with some new args instead of
env variables. Also netchecker-server no longer requires kubectl
container. Updating playbooks accordingly.

kube_apiserver_node_port_range should be accessible only
to kube-proxy and not be taken by a dynamic port allocation.

Potentially temporary if https://github.com/kubernetes/kubernetes/issues/40920
gets fixed.

- Remove weave CPU limits from .gitlab-ci.yml. Closes: #975
- Fix weave version in documentation

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

'absible_ssh_host' is deprecated in Ansible 2.0 and at least
'contrib/inventory_builder/inventory.py' uses 'ansible_host' instead.

- Docker 1.12 and further don't need nsenter hack. This patch removes
  it.  Also, it bumps the minimal version to 1.12.

Closes #776

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

- Set recommended CPU settings
- Cleans up upgrade to weave 1.82. The original WeaveWorks
daemonset definition uses weave-net name.
- Limit DS creation to master
- Combined 2 tasks into one with better condition

if the system doesn't have any config files at all.

Cleans up upgrade to weave 1.82. The original WeaveWorks
daemonset definition uses weave-net name.