* Specify that the cluster.yml playbook should run as root

This is a possible fix for #3388.
The following examples show the option `-b` too:

https://kubernetes.io/docs/setup/custom-cloud/kubespray/
https://github.com/kubernetes-incubator/kubespray/blob/master/docs/getting-started.md#starting-custom-deployment

* Update invocation to include specific root user

* Update comment text according to suggestions

Signed-off-by: Rui Cao <ruicao@alauda.io>

* Allow configuration of nginx proxy config path

* Fix the internal nginx configuration location

Signed-off-by: Johann Queuniet <contact@lordran.net>

* Update pre-install verify settings with network checks and etc.

* Remove upstream dns server check. It's bogus

* Update CoreDNS templates to newest version

* Add watch to ClusterRole. Fixes #3460

* Automatically infer bootstrap_os

* Rename bootstrap os to os_family

* Missing [all] sections inside the sample

* Update hosts.ini

* #3475 - make dnsmasq to send queries to all servers in upstream. Make dnsmasq config file customizable.

* Code style fixes. Return current behaviour for dnsmasq strict-order flag.

* Fix bootstrap_os/ubuntu idempotency

* Update bastion role

* move container_engine in sub-roles

* requires ansible 2.5

* ubuntu18 as first CI job

* Ability to specify ssl certificate duration and ssl key size - etcd/secrets

* Ability to specify ssl certificate duration and ssl key size - helm/contiv + fix contiv missing copy certs generation script

* Fix DNS loop when resolvconf_mode is set to host_resolvconf

* Make sure upstream_dns_servers is defined when using resolvconf_mode == 'host_resolvconf'

* Only set upstream dns servers on KubeDNS and CoreDNS if they are defined

* Only set upstream dns servers on KubeDNS and CoreDNS if they are defined

Split Vagrantfile Ubuntu versions into 1604 and 1804 (#3440)

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

- Local Volume StorageClass configuration is now manged by `local_volume_provisioner_storage_classes`, a list of maps that specifies local storage classes with `name` `host_dir` and `mount_dir` keys per entry
- Tasks and templates updated to loop through local volume storage classes
- Previous defaults for path/class names were not changed
- Fixed an issue where a `kubernetes/preinstall` was creating directories inconsistently with the `kubernetes-apps/external_provisioner/local_volume_provisioner` task

* Upgrade kubernetes to v1.12.0

Use kubeadm v1alpha3 config

* Upgrade coredns and etcd

* Upgrage docker to 18.06

Add note to README about offline environments

Internet access is not mandatory as long as the user configures all container image repositories to point to internal container registries, in case of on-premises installation with firewall rules preventing direct Internet access.

* Fix the jinja expression for openstack_tenant_id

OS_PROJECT_ID is obsolete in keystone v3 and jinja expression
doesn't set openstack_tenant_id as expected because of
undefined env var. Fixed the expression.

* Fix the dic iteration method in the kubelet template

Kubelet template rendering errors when additional Node lables are
added and using Python3. Update the method to be compatible to both
python2/3

Node lables doesn't work

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.

* Replace `openstack_compute_secgroup_v2` with `openstack_networking_secgroup_v2`

The `openstack_networking_secgroup_v2` resource allow specifications of
both ingress and egress. Nova security groups define ingress rules only.

This change will also allow for more user-friendly specified security
rules, as the different security group resources have different HCL
syntax.