Support ipvs mode for kube-proxy

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

Renamed variable from disable_volume_zone_conflict to volume_cross_zone_attachment and removed cloud provider condition; fix identation

Update checksum for kubeadm
Use v1.9.0 kubeadm params
Include hash of ca.crt for kubeadm join
Update tag for testing upgrades
Add workaround for testing upgrades
Remove scale CI scenarios because of slow inventory parsing
in ansible 2.4.x.

Change region for tests to us-central1 to
improve ansible performance

This does not update v1.9.0, but fixes two incompatibilities
when trying to deploy v1.9.0.

As we have seen with other containers, sometimes container removal fails on the first attempt due to some Docker bugs. Retrying typically corrects the issue.

This allows `kube_apiserver_insecure_port` to be set to 0 (disabled).

Rework of #1937 with kubeadm support

Also, fixed an issue in `kubeadm-migrate-certs` where the old apiserver cert was copied as the kubeadm key

* Allow setting --bind-address for apiserver hyperkube

This is required if you wish to configure a loadbalancer (e.g haproxy)
running on the master nodes without choosing a different port for the
vip from that used by the API - in this case you need the API to bind to
a specific interface, then haproxy can bind the same port on the VIP:

root@overcloud-controller-0 ~]# netstat -taupen | grep 6443
tcp        0      0 192.168.24.6:6443       0.0.0.0:*               LISTEN      0          680613     134504/haproxy
tcp        0      0 192.168.24.16:6443      0.0.0.0:*               LISTEN      0          653329     131423/hyperkube
tcp        0      0 192.168.24.16:6443      192.168.24.16:58404     ESTABLISHED 0          652991     131423/hyperkube
tcp        0      0 192.168.24.16:58404     192.168.24.16:6443      ESTABLISHED 0          652986     131423/hyperkube

This can be achieved e.g via:

kube_apiserver_bind_address: 192.168.24.16

* Address code review feedback

* Update kube-apiserver.manifest.j2

* Defaults for apiserver_loadbalancer_domain_name

When loadbalancer_apiserver is defined, use the
apiserver_loadbalancer_domain_name with a given default value.

Fix unconsistencies for checking if apiserver_loadbalancer_domain_name
is defined AND using it with a default value provided at once.

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

* Define defaults for LB modes in common defaults

Adjust the defaults for apiserver_loadbalancer_domain_name and
loadbalancer_apiserver_localhost to come from a single source, which is
kubespray-defaults. Removes some confusion and simplefies the code.

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

Thought this wasn't required at first but I forgot there's no auto flush at the end of these tasks since the `kubernetes/master` role is not the end of the play.

* Fixes an issue where apiserver and friends (controller manager, scheduler) were prevented from restarting after manifests/secrets are changed. This occurred when a replaced kubelet doesn't reconcile new master manifests, which caused old master component versions to linger during deployment. In my case this was causing upgrades from k8s 1.6/1.7 -> k8s 1.8 to fail
* Improves transitions from kubelet container to host kubelet by preventing issues where kubelet container reappeared during the deployment

This allows `kube_apiserver_insecure_port` to be set to 0 (disabled). It's working, but so far I have had to:

1. Make the `uri` module "Wait for apiserver up" checks use `kube_apiserver_port` (HTTPS)
2. Add apiserver client cert/key to the "Wait for apiserver up" checks
3. Update apiserver liveness probe to use HTTPS ports
4. Set `kube_api_anonymous_auth` to true to allow liveness probe to hit apiserver's /healthz over HTTPS (livenessProbes can't use client cert/key unfortunately)
5. RBAC has to be enabled. Anonymous requests are in the `system:unauthenticated` group which is granted access to /healthz by one of RBAC's default ClusterRoleBindings. An equivalent ABAC rule could allow this as well.

Changes 1 and 2 should work for everyone, but 3, 4, and 5 require new coupling of currently independent configuration settings. So I also added a new settings check.

Options:

1. The problem goes away if you have both anonymous-auth and RBAC enabled. This is how kubeadm does it. This may be the best way to go since RBAC is already on by default but anonymous auth is not.
2. Include conditional templates to set a different liveness probe for possible combinations of `kube_apiserver_insecure_port = 0`, RBAC, and `kube_api_anonymous_auth` (won't be possible to cover every case without a guaranteed authorizer for the secure port)
3. Use basic auth headers for the liveness probe (I really don't like this, it adds a new dependency on basic auth which I'd also like to leave independently configurable, and it requires encoded passwords in the apiserver manifest)

Option 1 seems like the clear winner to me, but is there a reason we wouldn't want anonymous-auth on by default? The apiserver binary defaults anonymous-auth to true, but kubespray's default was false.

It is now enabled by default in 1.8 with the api changed
to networking.k8s.io/v1 instead of extensions/v1beta1.

This should be done after kubeconfig is set for admin and
before network plugins are up.

* Refactor downloads to use download role directly

Also disable fact delegation so download delegate works acros OSes.

* clean up bools and ansible_os_family conditionals

Fixes #1129

* Add possibility to insert more ip adresses in certificates

* Add newline at end of files

* Move supp ip parameters to k8s-cluster group file

* Add supplementary addresses in kubeadm master role

* Improve openssl indexes

* Disable basic and token auth by default

* Add recommended security params

* allow basic auth to fail in tests

* Enable TLS authentication for kubelet

* Change file used to check kubeadm upgrade method

Test for ca.crt instead of admin.conf because admin.conf
is created during normal deployment.

* more fixes for upgrade

* add istio addon

* add addons to a ci job

* Clear admin kubeconfig when rotating certs

* Update main.yml

* Upgrade to kubernetes v1.8.0

hyperkube no longer contains rsync, so now use cp

* Enable node authorization mode

* change kube-proxy cert group name

These facts can be generated in defaults with a performance
boost.

Also cleaned up duplicate etcd var names.

Fix system namespace creation
Only rotate tokens when necessary