Use kubeadm_feature_gates instead of kube_feature_gates to leverage kubeadm feature gates and not to interfere with k8s components feature gates (#7447)

By default Ansible stat module compute checksum, list extended attributes and find mime type
To find all stat invocations that really use one of those:
git grep -F stat. | grep -vE 'stat.(islnk|exists|lnk_source|writeable)'

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

When enable_dual_stack_networks is set, we need to make sure
IPv6DualStack=true is set too, otherwise we end up with
a broken cluster.

When dns_mode was set to 'none' the coredns_server became an empty
string and invalid operation of adding string to list was executed.

* kube-proxy never gets deployed so need to remove it

Co-authored-by: Hans Feldt <hafe@users.noreply.github.com>

The variable is defined in `kubernetes/preinstall` role and used in several roles. Since `kubernetes/preinstall` is not always included when `ansible-playbook` is run with tag selectors (see #5734 for reason), they will fail, or individual roles must copy the same fact definitions (as in #3846). Moving the definition to the always-included `kubespray-defaults` role will resolve the dependency problem.

- This solves issue #5721 & #5713 (dupes)
  - Provide a cleaner default usage pattern for the download role
    around etcd that supports 'host' and 'docker' properly
  - Extract the 'etcdctl' as a separate task install piece and reuse it where
    appropriate
  - Update the kubeadm-etcd task to reflect the above change

* fedora coreos support
- bootstrap and new fact for

* fedora coreos support
- fix bootstrap condition

* fedora coreos support
- allow customize packages for fedora coreos bootstrap

* fedora coreos support
- prevent install ptyhon3 and epel via dnf for fedora coreos

* fedora coreos support
- handle all ostree like os in same way

* fedora coreos support
- handle all ostree like os in same way for crio

* fedora coreos support
- add fcos documentations

Change-Id: I33d46c7e0c5374467e22c5a652b282d1703dea85

Change-Id: If3e253a40782e03cde7fc4a91493517ae31fda17

* move flexvolume plugin directory creation to preinstall

* changes per pr feedback

* Enable kubeadm etcd mode

Uses cert commands from kubeadm experimental control plane to
enable non-master nodes to obtain etcd certs.

Related story: PROD-29434

Change-Id: Idafa1d223e5c6ceadf819b6f9c06adf4c4f74178

* Add validation checks and exclude calico kdd mode

Change-Id: Ic234f5e71261d33191376e70d438f9f6d35f358c

* Move etcd mode test to ubuntu flannel HA job

Change-Id: I9af6fd80a1bbb1692ab10d6da095eb368f6bc732

* rename etcd_mode to etcd_kubeadm_enabled

Change-Id: Ib196d6c8a52f48cae370b026f7687ff9ca69c172

* Add support for arm images for hyperkube, kubeadm and cni_binary

* Add dummy etcd checksum for arm

This commit adds dummy etcd checksum for arm to avoid "no attribute" error
during setup.

* Add etcd host assert check

* Add 1.13.4 checksums of kubeadm and hyperkube for arm

* Update checksums of kubeadm and hyperkube for arm

* Add dummy checksums for calicoctl_binary_checksums dict

* disable gather_facts because it causes tests to fail

* Remove architecture check for etcd, due to unable to run tests

Both kubedns and dnsmasq modes are long not maintained.
We should run dns_late steps at the end because sshd
makes DNS lookups during Ansible run and has 2s timeouts
for each failed lookup trying to connect to coredns before
it is ready.

* Remove non-kubeadm deployment

* More cleanup

* More cleanup

* More cleanup

* More cleanup

* Fix gitlab

* Try stop gce first before absent to make the delete process work

* More cleanup

* Fix bug with checking if kubeadm has already run

* Fix bug with checking if kubeadm has already run

* More fixes

* Fix test

* fix

* Fix gitlab checkout untill kubespray 2.8 is on quay

* Fixed

* Add upgrade path from non-kubeadm to kubeadm. Revert ssl path

* Readd secret checking

* Do gitlab checks from v2.7.0 test upgrade path to 2.8.0

* fix typo

* Fix CI jobs to kubeadm again. Fix broken hyperkube path

* Fix gitlab

* Fix rotate tokens

* More fixes

* More fixes

* Fix tokens

* [jjo] add kube-router support

Fixes cloudnativelabs/kube-router#147.

* add kube-router as another network_plugin choice
* support most used kube-router flags via
  `kube_router_foo` vars as other plugins
* implement replacing kube-proxy (--run-service-proxy=true) via
  `kube_proxy_mode: none`, verified in a _non kubeadm_enabled_
  install, should also work for recent kubeadm releases via
  `skipKubeProxyInstall: true` config

* [jjo] address PR#3339 review from @woopstar

* add busybox image used by kube-router to downloads

* fix busybox download groups key

* rework kubeadm_enabled + kube_router_run_service_proxy

- verify it working ok w/the kubeadm_enabled and
  kube_router_run_service_proxy true or false

- introduce `kube_proxy_remove` fact, to decouple logic
  from kube_proxy_mode (which affects kubeadm configmap
  settings, thus no-good to ab-use it to 'none')

* improve kube-router.md re: kubeadm_enabled and kube_router_run_service_proxy

* address @woopstar latest review

* add inventory/sample/group_vars/k8s-cluster/k8s-net-kube-router.yml

* fix kube_router_run_service_proxy conditional for kube-proxy removal

* fix kube_proxy_remove fact (w/ |bool), add some needed kube-proxy tags on my and existing changes

* update kube-router tolerations for 1.12 compatibility

* add PriorityClass to kube-router DaemonSet

* calico upgrade to v3

* update calico_rr version

* add missing file

* change contents of main.yml as it was left old version

* enable network policy by default

* remove unneeded task

* Fix kubelet calico settings

* fix when statement

* switch back to node-kubeconfig.yaml

Added CoreDNS to downloads

Updated with labels. Should now work without RBAC too

Fix DNS settings on hosts

Rename CoreDNS service from kube-dns to coredns

Add rotate based on http://edgeofsanity.net/rant/2017/12/20/systemd-resolved-is-broken.html

Updated docs with CoreDNS info

Added labels and fixed minor settings from official yaml file: https://github.com/kubernetes/kubernetes/blob/release-1.9/cluster/addons/dns/coredns.yaml.sed

Added a secondary deployment and secondary service ip. This is to mitigate dns timeouts and create high resitency for failures. See discussion at 'https://github.com/coreos/coreos-kubernetes/issues/641#issuecomment-281174806'

Set dns list correct. Thanks to @whereismyjetpack

Only download KubeDNS or CoreDNS if selected

Move dns cleanup to its own file and import tasks based on dns mode

Fix install of KubeDNS when dnsmask_kubedns mode is selected

Add new dns option coredns_dual for dual stack deployment. Added variable to configure replicas deployed. Updated docs for dual stack deployment. Removed rotate option in resolv.conf.

Run DNS manifests for CoreDNS and KubeDNS

Set skydns servers on dual stack deployment

Use only one template for CoreDNS dual deployment

Set correct cluster ip for the dns server

Cloud resolvers are mandatory for hosts on GCE and OpenStack
clouds. The 8.8.8.8 alternative resolver was dropped because
there is already a default nameserver. The new var name
reflects the purpose better.

Also restart apiserver when modifying dns settings.

* 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

When VPC is used, external DNS might not be available. This patch change
behavior to use metadata service instead of external DNS when
upstream_dns_servers is not specified.

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