Merge pull request #862 from bogdando/docs

Update docs

README.md

@@ -1,4 +1,4 @@
-![Kubespray Logo](http://s9.postimg.org/md5dyjl67/kubespray_logoandkubespray_small.png)
+![Kubernetes Logo](https://s28.postimg.org/lf3q4ocpp/k8s.png)
 
 ##Deploy a production ready kubernetes cluster
 
@@ -14,75 +14,88 @@ If you have questions, join us on the [kubernetes slack](https://slack.k8s.io),
 To deploy the cluster you can use :
 
 [**kargo-cli**](https://github.com/kubespray/kargo-cli) <br>
-**Ansible** usual commands <br>
+**Ansible** usual commands and [**inventory builder**](https://github.com/kubernetes-incubator/kargo/blob/master/contrib/inventory_builder/inventory.py) <br>
 **vagrant** by simply running `vagrant up` (for tests purposes) <br>
 
 
 *  [Requirements](#requirements)
+*  [Kargo vs ...](docs/comparisons.md)
 *  [Getting started](docs/getting-started.md)
+*  [Ansible inventory and tags](docs/ansible.md)
+*  [Deployment data variables](docs/vars.md)
+*  [DNS stack](docs/dns-stack.md)
+*  [HA mode](docs/ha-mode.md)
+*  [Network plugins](#network-plugins)
 *  [Vagrant install](docs/vagrant.md)
 *  [CoreOS bootstrap](docs/coreos.md)
-*  [Ansible variables](docs/ansible.md)
+*  [Downloaded artifacts](docs/downloads.md)
 *  [Cloud providers](docs/cloud.md)
 *  [OpenStack](docs/openstack.md)
 *  [AWS](docs/aws.md)
 *  [Azure](docs/azure.md)
-*  [Network plugins](#network-plugins)
+*  [Large deployments](docs/large-deployments.md)
+*  [Upgrades basics](docs/upgrades.md)
 *  [Roadmap](docs/roadmap.md)
 
 Supported Linux distributions
 ===============
 
-* **CoreOS**
-* **Debian** Wheezy, Jessie
-* **Ubuntu** 14.10, 15.04, 15.10, 16.04
-* **Fedora** 23
+* **Container Linux by CoreOS**
+* **Debian** Jessie
+* **Ubuntu** 16.04
 * **CentOS/RHEL** 7
 
-Versions
---------------
+Note: Upstart/SysV init based OS types are not supported.
+
+Versions of supported components
+--------------------------------
 
-[kubernetes](https://github.com/kubernetes/kubernetes/releases) v1.4.6 <br>
+[kubernetes](https://github.com/kubernetes/kubernetes/releases) v1.5.1 <br>
 [etcd](https://github.com/coreos/etcd/releases) v3.0.6 <br>
 [flanneld](https://github.com/coreos/flannel/releases) v0.6.2 <br>
-[calicoctl](https://github.com/projectcalico/calico-docker/releases) v0.22.0 <br>
+[calicoctl](https://github.com/projectcalico/calico-docker/releases) v0.23.0 <br>
+[canal](https://github.com/projectcalico/canal) (given calico/flannel versions) <br>
 [weave](http://weave.works/) v1.6.1 <br>
-[docker](https://www.docker.com/) v1.10.3 <br>
+[docker](https://www.docker.com/) v1.12.5 <br>
+[rkt](https://coreos.com/rkt/docs/latest/) v1.21.0 <br>
 
+Note: rkt support as docker alternative is limited to control plane (etcd and
+kubelet). Docker is still used for Kubernetes cluster workloads and network
+plugins' related OS services. Also note, only one of the supported network
+plugins can be deployed for a given single cluster.
 
 Requirements
 --------------
 
 * The target servers must have **access to the Internet** in order to pull docker images.
 * The **firewalls are not managed**, you'll need to implement your own rules the way you used to.
-in order to avoid any issue during deployment you should disable your firewall
+in order to avoid any issue during deployment you should disable your firewall.
+* The target servers are configured to allow **IPv4 forwarding**.
 * **Copy your ssh keys** to all the servers part of your inventory.
-* **Ansible v2.1 (or newer) and python-netaddr**
+* **Ansible v2.2 (or newer) and python-netaddr**
 
 
 ## Network plugins
-You can choose between 3 network plugins. (default: `flannel` with vxlan backend)
+You can choose between 4 network plugins. (default: `flannel` with vxlan backend)
 
 * [**flannel**](docs/flannel.md): gre/vxlan (layer 2) networking.
 
 * [**calico**](docs/calico.md): bgp (layer 3) networking.
 
-* **weave**: Weave is a lightweight container overlay network that doesn't require an external K/V database cluster. <br>
-(Please refer to `weave` [troubleshooting documentation](http://docs.weave.works/weave/latest_release/troubleshooting.html))
+* [**canal**](https://github.com/projectcalico/canal): a composition of calico and flannel plugins.
 
-The choice is defined with the variable `kube_network_plugin`
+* **weave**: Weave is a lightweight container overlay network that doesn't require an external K/V database cluster. <br>
+(Please refer to `weave` [troubleshooting documentation](http://docs.weave.works/weave/latest_release/troubleshooting.html)).
 
+The choice is defined with the variable `kube_network_plugin`. There is also an
+option to leverage built-in cloud provider networking instead.
+See also [Network checker](docs/netcheck.md).
 
 ## CI Tests
 
-[![Build Status](https://travis-ci.org/kubernetes-incubator/kargo.svg)](https://travis-ci.org/kubernetes-incubator/kargo) </br>
-
-### Google Compute Engine
+![Gitlab Logo](https://s27.postimg.org/wmtaig1wz/gitlabci.png)
 
-              | Calico        | Flannel       | Weave         |
-------------- | ------------- | ------------- | ------------- |
-Ubuntu Xenial |[![Build Status](https://ci.kubespray.io/job/kargo-gce-xenial-calico/badge/icon)](https://ci.kubespray.io/job/kargo-gce-xenial-calico/)|[![Build Status](https://ci.kubespray.io/job/kargo-gce-xenial-flannel/badge/icon)](https://ci.kubespray.io/job/kargo-gce-xenial-flannel/)|[![Build Status](https://ci.kubespray.io/job/kargo-gce-xenial-weave/badge/icon)](https://ci.kubespray.io/job/kargo-gce-xenial-weave)|
-CentOS 7      |[![Build Status](https://ci.kubespray.io/job/kargo-gce-centos7-calico/badge/icon)](https://ci.kubespray.io/job/kargo-gce-centos7-calico/)|[![Build Status](https://ci.kubespray.io/job/kargo-gce-centos7-flannel/badge/icon)](https://ci.kubespray.io/job/kargo-gce-centos7-flannel/)|[![Build Status](https://ci.kubespray.io/job/kargo-gce-centos7-weave/badge/icon)](https://ci.kubespray.io/job/kargo-gce-centos7-weave/)|
-CoreOS (stable) |[![Build Status](https://ci.kubespray.io/job/kargo-gce-coreos-calico/badge/icon)](https://ci.kubespray.io/job/kargo-gce-coreos-calico/)|[![Build Status](https://ci.kubespray.io/job/kargo-gce-coreos-flannel/badge/icon)](https://ci.kubespray.io/job/kargo-gce-coreos-flannel/)|[![Build Status](https://ci.kubespray.io/job/kargo-gce-coreos-weave/badge/icon)](https://ci.kubespray.io/job/kargo-gce-coreos-weave/)|
+[![Build graphs](https://gitlab.com/kargo-ci/kubernetes-incubator__kargo/badges/master/build.svg)](https://gitlab.com/kargo-ci/kubernetes-incubator__kargo/pipelines) </br>
 
-CI tests sponsored by Google (GCE), and [teuto.net](https://teuto.net/) for OpenStack.
+CI/end-to-end tests sponsored by Google (GCE), and [teuto.net](https://teuto.net/) for OpenStack.
+See the [test matrix](docs/test_cases.md) for details.

docs/ansible.md

@@ -45,9 +45,38 @@ kube-master
 etcd
 ```
 
-Group vars
---------------
-The main variables to change are located in the directory ```inventory/group_vars/all.yml```.
+Group vars and overriding variables precedence
+----------------------------------------------
+
+The group variables to control main deployment options are located in the directory
+```inventory/group_vars```.
+
+There are also role vars for docker, rkt, kubernetes preinstall and master roles.
+According to the [ansible docs](http://docs.ansible.com/ansible/playbooks_variables.html#variable-precedence-where-should-i-put-a-variable),
+those cannot be overriden from the group vars. In order to override, one should use
+the `-e ` runtime flags (most simple way) or other layers described in the docs.
+
+Kargo uses only a few layers to override things (or expect them to
+be overriden for roles):
+
+Layer | Comment
+------|--------
+**role defaults** | provides best UX to override things for Kargo deployments
+inventory vars | Unused
+**inventory group_vars** | Expects users to use ``all.yml``,``k8s-cluster.yml`` etc. to override things
+inventory host_vars | Unused
+playbook group_vars | Unuses
+playbook host_vars | Unused
+**host facts** | Kargo overrides for internal roles' logic, like state flags
+play vars | Unused
+play vars_prompt | Unused
+play vars_files | Unused
+registered vars | Unused
+set_facts | Kargo overrides those, for some places
+**role and include vars** | Provides bad UX to override things! Use extra vars to enforce
+block vars (only for tasks in block) | Kargo overrides for internal roles' logic
+task vars (only for the task) | Unused for roles, but only for helper scripts
+**extra vars** (always win precedence) | override with ``ansible-playbook -e @foo.yml``
 
 Ansible tags
 ------------
@@ -132,5 +161,5 @@ bastion host.
 bastion ansible_ssh_host=x.x.x.x
 ```
 
-For more information about Ansible and bastion hosts, read 
-[Running Ansible Through an SSH Bastion Host](http://blog.scottlowe.org/2015/12/24/running-ansible-through-ssh-bastion-host/)
+For more information about Ansible and bastion hosts, read
+[Running Ansible Through an SSH Bastion Host](http://blog.scottlowe.org/2015/12/24/running-ansible-through-ssh-bastion-host/)

docs/comparisons.md

@@ -1,3 +1,25 @@
 Kargo vs [Kops](https://github.com/kubernetes/kops)
 ---------------
-Kargo runs on bare metal and most clouds, using Ansible as its substrate for provisioning and orchestration. Kops performs the provisioning and orchestration itself, and as such is less flexible in deployment platforms. For people with familiarity with Ansible, existing Ansible deployments or the desire to run a Kubernetes cluster across multiple platforms, Kargo is a good choice. Kops, however, iss more tightly integrated with the unique features of the clouds it supports so it could be a better choice if you know that you will only be using one platform for the foreseeable future.
+
+Kargo runs on bare metal and most clouds, using Ansible as its substrate for
+provisioning and orchestration. Kops performs the provisioning and orchestration
+itself, and as such is less flexible in deployment platforms. For people with
+familiarity with Ansible, existing Ansible deployments or the desire to run a
+Kubernetes cluster across multiple platforms, Kargo is a good choice. Kops,
+however, is more tightly integrated with the unique features of the clouds it
+supports so it could be a better choice if you know that you will only be using
+one platform for the foreseeable future.
+
+Kargo vs [Kubeadm](https://github.com/kubernetes/kubeadm)
+------------------
+
+Kubeadm provides domain Knowledge of Kubernetes clusters' life cycle
+management, including self-hosted layouts, dynamic discovery services and so
+on. Had it belong to the new [operators world](https://coreos.com/blog/introducing-operators.html),
+it would've likely been named a "Kubernetes cluster operator". Kargo however,
+does generic configuration management tasks from the "OS operators" ansible
+world, plus some initial K8s clustering (with networking plugins included) and
+control plane bootstrapping. Kargo [strives](https://github.com/kubernetes-incubator/kargo/issues/553)
+to adopt kubeadm as a tool in order to consume life cycle management domain
+knowledge from it and offload generic OS configuration things from it, which
+hopefully benefits both sides.