Configurable Parameters in Kargo
================================

#### Generic Ansible variables

You can view facts gathered by Ansible automatically
[here](http://docs.ansible.com/ansible/playbooks_variables.html#information-discovered-from-systems-facts).

Some variables of note include:

* *ansible_user*: user to connect to via SSH
* *ansible_default_ipv4.address*: IP address Ansible automatically chooses.
  Generated based on the output from the command ``ip -4 route get 8.8.8.8``

#### Common vars that are used in Kargo

* *calico_version* - Specify version of Calico to use
* *calico_cni_version* - Specify version of Calico CNI plugin to use
* *docker_version* - Specify version of Docker to used (should be quoted
  string)
* *etcd_version* - Specify version of ETCD to use
* *ipip* - Enables Calico ipip encapsulation by default
* *hyperkube_image_repo* - Specify the Docker repository where Hyperkube
  resides
* *hyperkube_image_tag* - Specify the Docker tag where Hyperkube resides
* *kube_network_plugin* - Changes k8s plugin to Calico
* *kube_proxy_mode* - Changes k8s proxy mode to iptables mode
* *kube_version* - Specify a given Kubernetes hyperkube version
* *searchdomains* - Array of DNS domains to search when looking up hostnames
* *nameservers* - Array of nameservers to use for DNS lookup

#### Addressing variables

* *ip* - IP to use for binding services (host var)
* *access_ip* - IP for other hosts to use to connect to. Often required when
  deploying from a cloud, such as OpenStack or GCE and you have separate
  public/floating and private IPs.
* *ansible_default_ipv4.address* - Not Kargo-specific, but it is used if ip
  and access_ip are undefined
* *loadbalancer_apiserver* - If defined, all hosts will connect to this
  address instead of localhost for kube-masters and kube-master[0] for
  kube-nodes. See more details in the
  [HA guide](https://github.com/kubernetes-incubator/kargo/blob/master/docs/ha-mode.md).
* *loadbalancer_apiserver_localhost* - If enabled, all hosts will connect to
  the apiserver internally load balanced endpoint.  See more details in the
  [HA guide](https://github.com/kubernetes-incubator/kargo/blob/master/docs/ha-mode.md).

#### Cluster variables

Kubernetes needs some parameters in order to get deployed. These are the
following default cluster paramters:

* *cluster_name* - Name of cluster (default is cluster.local)
* *domain_name* - Name of cluster DNS domain (default is cluster.local)
* *kube_network_plugin* - Plugin to use for container networking
* *kube_service_addresses* - Subnet for cluster IPs (default is
  10.233.0.0/18). Must not overlap with kube_pods_subnet
* *kube_pods_subnet* - Subnet for Pod IPs (default is 10.233.64.0/18). Must not
  overlap with kube_service_addresses.
* *kube_network_node_prefix* - Subnet allocated per-node for pod IPs. Remainin
  bits in kube_pods_subnet dictates how many kube-nodes can be in cluster.
* *dns_setup* - Enables dnsmasq
* *dns_server* - Cluster IP for dnsmasq (default is 10.233.0.2)
* *skydns_server* - Cluster IP for KubeDNS (default is 10.233.0.3)
* *cloud_provider* - Enable extra Kubelet option if operating inside GCE or
  OpenStack (default is unset)
* *kube_hostpath_dynamic_provisioner* - Required for use of PetSets type in
  Kubernetes

Note, if cloud providers have any use of the ``10.233.0.0/16``, like instances'
private addresses, make sure to pick another values for ``kube_service_addresses``
and ``kube_pods_subnet``, for example from the ``172.18.0.0/16``.

#### DNS variables

By default, dnsmasq gets set up with 8.8.8.8 as an upstream DNS server and all
other settings from your existing /etc/resolv.conf are lost. Set the following
variables to match your requirements.

* *upstream_dns_servers* - Array of upstream DNS servers configured on host in
  addition to Kargo deployed DNS
* *nameservers* - Array of DNS servers configured for use in dnsmasq
* *searchdomains* - Array of up to 4 search domains
* *skip_dnsmasq* - Don't set up dnsmasq (use only KubeDNS)

For more information, see [DNS
Stack](https://github.com/kubernetes-incubator/kargo/blob/master/docs/dns-stack.md).

#### Other service variables

* *docker_options* - Commonly used to set
  ``--insecure-registry=myregistry.mydomain:5000``
* *http_proxy/https_proxy/no_proxy* - Proxy variables for deploying behind a
  proxy

#### User accounts

Kargo sets up two Kubernetes accounts by default: ``root`` and ``kube``. Their
passwords default to changeme. You can set this by changing ``kube_api_pwd``.

