* weave: Upgrade to 2.5.0

Upstream Changes:

-   weave 2.5.0 (https://github.com/weaveworks/weave/releases/tag/v2.5.0)
-   Adds support for Kubernetes `hostPort` mapping
-   Adds support for Kubernetes `ipBlock` NetworkPolicy feature

Our Changes:

-   Templates sync with upstream manifests
-   Remove legacy nodePort fix

* BC for weave < 2.5.0

* Revert netchecker image and version

* Create namespace for netchecker

* Remove extra slashes

* Remove Vault

* Remove reference to 'kargo' in the doc

* change check order

* Adds support for Multus (multiple interfaces) CNI plugin

Multus is a latin word for "Multi". As the name suggests, it acts as a
Multi plugin in Kubernetes and provides multiple network interface
support in a pod. Multus uses the concept of invoking delegates by
grouping multiple plugins into delegates and invoking them in the
sequential order of the CNI configuration file provided in json format.

* Change CNI version (0.1.0->0.3.1) of Contiv to be compatible with Multus

Upstream Changes:

   - coredns v1.2.5 (https://github.com/coredns/coredns/releases/tag/v1.2.5)

NOTE:

   - Switch image repo to https://hub.docker.com/r/coredns/coredns/ (https://github.com/kubernetes-incubator/kubespray/pull/3595#issuecomment-433962973)

This reverts commit 8ba6b601.

Upstream Changes:

-   ingress-nginx 0.20.0 (https://github.com/kubernetes/ingress-nginx/releases/tag/nginx-0.20.0)

Our Changes:

-   Sync templates with upstream changes

* codestyle tests

* Download destination can be different than local_release_dir

kube-router v0.2.1 highlights from changelog:
- IPv6 WIP but pretty close to full working functionality
- fully support network policy semantics with addition of support for
  ipblock and except

* [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

https://github.com/kubernetes/kubernetes/issues/69214

* Upgrade kubernetes to v1.12.0

Use kubeadm v1alpha3 config

* Upgrade coredns and etcd

* Upgrage docker to 18.06

According to the documentation, container images are described
by vars like `foo_image_repo` and `foo_image_tag`.
The variables netcheck_{agent,server}_{img_repo,tag} do not
follow that convention.

Keep a list of checksums for kubeadm and hyperkube downloads.
Makes it easier to switch version

Upstream Changes:

-   weave 2.4.1 (https://github.com/weaveworks/weave/releases/tag/v2.4.1)

Our Changes:

-   Templates sync with upstream manifests

Upstream Changes:

-   cert-manager 0.5.0 (https://github.com/jetstack/cert-manager/releases/tag/v0.5.0)

Our Changes:

-   Templates sync with upstream manifests

Upstream Changes:

-   ingress-nginx 0.19.0 (https://github.com/kubernetes/ingress-nginx/releases/tag/nginx-0.19.0)

Our Changes:

-   Sync templates with upstream changes

Upstream Changes:

-   cephfs-provisioner v2.1.0-k8s1.11 (https://github.com/kubernetes-incubator/external-storage/releases/tag/cephfs-provisioner-v2.1.0-k8s1.11)

Our Changes:

-   Sync clusterrole and role with upstream changes

Upstream Changes:

-   coredns v1.2.2 (https://github.com/coredns/coredns/releases/tag/v1.2.2)

NOTE:

-   coredns image for 1.2.0 and 1.2.1 had been removed from https://console.cloud.google.com/gcr/images/google-containers/GLOBAL/coredns