consul is an orchestration mechanism with fault-tolerance based on the gossip protocol and a key/value store that is strongly consistent. Hiera-consul will allow hiera to write to the k/v store for metadata centralisation and harmonisation.

The following hiera.yaml should get you started.

:backends:
  - consul

:consul:
  :host: 127.0.0.1
  :port: 8500
  :base: /v1/kv/configuration

:hierarchy:
  - "%{fqdn}
  - common

As this module uses http to talk with Consul API the following parameters are also valid and available

:consul:
  :host: 
    - 127.0.0.1
    - 10.10.1.1
    - 172.16.1.1
  :port: 8500
  :use_ssl: false
  :ssl_verify: false
  :ssl_cert: /path/to/cert
  :ssl_key: /path/to/key
  :ssl_ca_cert: /path/to/ca/cert
  :failure: graceful
  :ignore_404: true
  :token: acl-uuid-token
  :paths:
    - /v1/kv/configuration/%{fqdn}
    - /v1/kv/configuration/common

Note that :base and :paths are mutually exclusive parameters.

You can also query the Consul catalog for values by adding catalog resources in your paths, the values will be returned as an array so you will need to parse accordingly.

:backends:
  - consul

:consul:
  :host: 127.0.0.1
  :port: 8500
  :paths:
    - /v1/kv/configuration/%{fqdn}
    - /v1/kv/configuration/common
    - /v1/catalog/service
    - /v1/catalog/node

This function will allow you to read information out of a consul Array, as an example here we recover node IPs based on a service:

$consul_service_array = hiera('rabbitmq',[])
$mq_cluster_nodes = consul_info($consul_service_array, 'Address')

In this example $mq_cluster_nodes will have a hash with all the IP addresses related to that service

You can also feed it more than one field and a separator and it will generate a composed string

$consul_service_array = hiera('rabbitmq',[])
$mq_cluster_nodes = consul_info($consul_service_array, [ 'Address', 'Port' ], ':')

The result will return an array like this: [ AddressA:PortA, AddressB:PortB ]

If you want to flatten the output array you can always use join from the Puppet stdlib.

$myresult = join($mq_cluster_nodes, ",")

Codebase borrowed wholesale (before refactoring) from lynxman which in turn was heavily based on etcd-hiera written by @garethr which was inspired by hiera-http from @crayfishx.

Thanks to @mitchellh for writing such wonderful tools and the API Documentation

Thanks for their contributions to Wei Tie, Derek Tracy, Michael Chapman, Kyle O'Donnell and AJ