* kubedns & kubedns-autoscaler: Stick to master nodes.
- Tolerate only master nodes and not any NoSchedule taint
- Pods are on different nodes
- Pods are required to be on a master node.
* kubedns: use soft nodeAffinity.
Prefer to be on a master node, don't require.
* coredns: Stick to (different) master nodes.
- Pods are on different nodes
- Pods are preferred to be on a master node.
Currently all the gcr.io images used in kubespray can only run on x86.
Also gcr.io has not fully support multi-arch docker images.
Add extra var "image_arch" (default is amd64) to support running other
platforms, like arm64.
Change-Id: I8e1c9af533c021cb96ade291a1ce58773b40e271
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
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
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.
