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

* Added option for encrypting secrets to etcd

* Fix keylength to 32

* Forgot the default

* Rename secrets.yaml to secrets_encryption.yaml

* Fix static path for secrets file to use ansible variable

* Rename secrets.yaml.j2 to secrets_encryption.yaml.j2

* Base64 encode the token

* Fixed merge error

* Changed path to credentials dir

* Update path to secrets file which is now readable inside the apiserver container. Set better file permissions

* Add encryption option to k8s-cluster.yml

Setting the following:

```
kube_kubeadm_controller_extra_args:
  address: 0.0.0.0
  terminated-pod-gc-threshold: "100"
```

Results in `terminated-pod-gc-threshold: 100` in the kubeadm config file. But it has to be a string to work.

1. 404 link url
2. kubelet_authentication_token_webhook is not work
3. kube_reserved variable set twice

Explicitly defines the --kubelet-preferred-address-types parameter #2418

Fixes #2453

Add `state: directory` to `file` task so that `recurse: yes` will actually take effect and ensure
certs/keys have the right file mode and owner

to the API server configuration.

This solves the problem where if you have non-resolvable node names,
and try to scale the server by adding new nodes, kubectl commands
start to fail for newly added nodes, giving a TCP timeout error when
trying to resolve the node hostname against a public DNS.

Add etcd-events cluster for kube-apiserver

* Fix run kubectl error

Fix run kubectl error when first master doesn't work

* if access_ip is define use first_kube_master
else different master use a different ip

* Delete set first_kube_master and use kube_apiserver_access_address

* Fixed generate front proxy client certs with vault

* fix vault cert management

* Distrebute etcd node certs to vault hosts

Adding health checking to kube proxy. Fixes #2308

* Set filemode to 0640

weave-net.yml file is readable by all users on the host. It however contains the weave_password to encrypt all pod communication. It should only be readable by root.

* Set mode 0640 on users_file with basic auth

* Added cilium support

* Fix typo in debian test config

* Remove empty lines

* Changed cilium version from <latest> to <v1.0.0-rc3>

* Add missing changes for cilium

* Add cilium to CI pipeline

* Fix wrong file name

* Check kernel version for cilium

* fixed ci error

* fixed cilium-ds.j2 template

* added waiting for cilium pods to run

* Fixed missing EOF

* Fixed trailing spaces

* Fixed trailing spaces

* Fixed trailing spaces

* Fixed too many blank lines

* Updated tolerations,annotations in cilium DS template

* Set cilium_version to iptables-1.9 to see if bug is fixed in CI

* Update cilium image tag to v1.0.0-rc4

* Update Cilium test case CI vars filenames

* Add optional prometheus flag, adjust initial readiness delay

* Update README.md with cilium info

xtables lock was missing. Added new option for oom-score to make sure it's not killed in an OOM situation before regular pods.

`FAILED! => {"changed": false, "msg": "AnsibleFilterError: Version comparison: unorderable types: str() < int()"}`

Even though there it kubeadm_token_ttl=0 which means that kubeadm token never expires, it is not present in `kubeadm token list` after cluster is provisioned (at least after it is running for some time) and there is issue regarding this https://github.com/kubernetes/kubeadm/issues/335, so we need to create a new temporary token during the cluster upgrade.

Ansible automatically installs the python-apt package when using
the 'apt' Ansible module, if python-apt is not present. This patch
removes the (unneeded) explicit installation in the Kubespray
'preinstall' role.

Rename from aggregator-proxy-client to front-proxy-client to match kubeadm design. Added kubeadm support too. Changed to use variables set and not hardcode paths. Still missing cert generation for Vault

1.Disalbe install epel-release rpm on Centos/Redhat
2.Use yum install epel-release