peers

Table of Contents

1. Description
2. Setup
3. Usage
4. Limitations
5. Development

Description

This module includes functions to obtain an array of nodes with puppet resources that match specific criteria. This is useful for things like getting a dynamic list of nodes that are cluster members. The module does not use exported resources, although puppetdb is required.

Setup

Deploying the module to an environment should be all that is necessary to use the included functions. The module does not manage any resources.

Usage

The following example uses the 'peers::resource_by_param' function in a manifest to get an array of nodes that have the 'elasticsearch' class assigned with the 'config.cluster.name' parameter set to 'cluster-1'. Based on the returned array you can do things like check if the current node is already a member, join the cluster, adjust the value for quorum, and update seed hosts.

$elk_servers = peers::resource_by_param('elasticsearch', 'config.cluster.name', 'cluster-1')

The functions default to the node's environment, but this can be overridden by passing another parameter to the function. To repeat the last Elasticsearch query, but in the "test" environment:

$elk_servers = peers::resource_by_param('elasticsearch', 'config.cluster.name', 'cluster-1', 'test')

The other module functions enable searching for nodes based on different criteria. See the module reference for details, but here's another example to get nodes with the 'elasticsearch' module assigned, this time matching nodes based on the trusted fact extension 'pp_cluster' set to the value of 'cluster-01':

$elk_servers = peers::resource_by_tx('elasticsearch', 'pp_cluster', 'cluster-01')

Besides direct configuration of the Elasticsearch cluster, the array of cluster nodes could be useful to setup a kibana resource:

$elk_servers = peers::resource_by_param('elasticsearch', 'config.cluster.name', 'cluster-1')

class { 'kibana':
  config  => {
    'server.host'         => fact('networking.ip'),
    'elasticsearch.hosts' => $elk_servers.map |$node| { "http://${node}:9200" },
  },
}

Limitations

The module uses a fairly basic puppetdb query and should work with all supported Puppet distributions where puppetdb is included.

Development

I'd appreciate any feedback. To contribute to development, fork the source and submit a pull request.

Reference

Table of Contents

Functions

• peers::resource_by_fact: Return an array of nodes by certname that have a resource matching the given class, fact value, and environment.
• peers::resource_by_param: Return an array of nodes by certname that have a resource matching the given class, parameter value, and environment.
• peers::resource_by_param_w_fact: Return a hash of certnames mapped to fact values when the node has a resource matching
• peers::resource_by_tag: Return an array of nodes by certname that have a resource matching the given class, tag, and environment.
• peers::resource_by_tx: Return an array of nodes by certname that have a resource matching the given class, trusted extension value, and environment.

Functions

peers::resource_by_fact

Type: Puppet Language

Return an array of nodes by certname that have a resource matching the given class, fact value, and environment.

Examples

Get an array of nodes with the 'elasticsearch' class assigned that have the value

of 'cluster-01' assigned as the fact named 'cluster':

$elk_servers = peers::resource_by_fact('elasticsearch', 'cluster', 'cluster-01')

peers::resource_by_fact(String $class, String $fact, String $value, String $env = $server_facts['environment'])

The peers::resource_by_fact function.

Returns: Array certnames that match function parameters

Examples

Get an array of nodes with the 'elasticsearch' class assigned that have the value

of 'cluster-01' assigned as the fact named 'cluster':

$elk_servers = peers::resource_by_fact('elasticsearch', 'cluster', 'cluster-01')

class

Data type: String

The class name associated with the resource.

fact

Data type: String

The fact name from the node with the resource.

value

Data type: String

The value of the given fact for the node.

env

Data type: String

An optional environment to search for matching resources. Defaults to the node environment.

peers::resource_by_param

Type: Puppet Language

Return an array of nodes by certname that have a resource matching the given class, parameter value, and environment.

Examples

Get an array of nodes with the 'elasticsearch' class assigned that have the value

of 'cluster-01' assigned as the class parameter 'config.cluster.name':

$elk_servers = peers::resource_by_param('elasticsearch', 'config.cluster.name', 'cluster-01')

peers::resource_by_param(String $class, String $parameter, String $value, String $env = $server_facts['environment'])

The peers::resource_by_param function.

Returns: Array certnames that match function parameters

Examples

Get an array of nodes with the 'elasticsearch' class assigned that have the value

of 'cluster-01' assigned as the class parameter 'config.cluster.name':

$elk_servers = peers::resource_by_param('elasticsearch', 'config.cluster.name', 'cluster-01')

class

Data type: String

The class name associated with the resource.

parameter

Data type: String

The parameter name associated with the resource.

value

Data type: String

The value of the given parameter associated with the resource.

env

Data type: String

An optional environment to search for matching resources. Defaults to the node environment.

peers::resource_by_param_w_fact

Type: Puppet Language

the given class, parameter value, fact name, and environment.

Examples

Get a hash where the keys are nodes with the 'elasticsearch' class assigned that have the value

of 'cluster-01' assigned as the class parameter 'config.cluster.name', and the hash values are from the
custom fact 'node_cert_serial':

$elk_servers = peers::resource_by_param('elasticsearch', 'config.cluster.name', 'cluster-01', 'node_cert_serial')

peers::resource_by_param_w_fact(String $class, String $parameter, String $value, String $fact, String $env = $server_facts['environment'])

the given class, parameter value, fact name, and environment.

Returns: Hash Hash keys are certnames with values set to value of the given fact for the node.

Examples

Get a hash where the keys are nodes with the 'elasticsearch' class assigned that have the value

of 'cluster-01' assigned as the class parameter 'config.cluster.name', and the hash values are from the
custom fact 'node_cert_serial':

$elk_servers = peers::resource_by_param('elasticsearch', 'config.cluster.name', 'cluster-01', 'node_cert_serial')

class

Data type: String

The class name associated with the resource.

parameter

Data type: String

The parameter name associated with the resource.

value

Data type: String

The value of the given parameter associated with the resource.

fact

Data type: String

The name of some fact where the value will be paired with the certname in the returned hash.

env

Data type: String

An optional environment to search for matching resources. Defaults to the node environment.

peers::resource_by_tag

Type: Puppet Language

Return an array of nodes by certname that have a resource matching the given class, tag, and environment.

peers::resource_by_tag(String $class, String $tag, String $env = $server_facts['environment'])

The peers::resource_by_tag function.

Returns: Array certnames that match function parameters

class

Data type: String

The class name associated with the resource.

tag

Data type: String

The value of a tag associated with the resource.

env

Data type: String

An optional environment to search for matching resources. Defaults to the node environment.

peers::resource_by_tx

Type: Puppet Language

Return an array of nodes by certname that have a resource matching the given class, trusted extension value, and environment.

Examples

Get an array of nodes with the 'elasticsearch' class assigned that have the value

of 'cluster-01' assigned as the trusted fact extension 'pp_cluster':

$elk_servers = peers::resource_by_tx('elasticsearch', 'pp_cluster', 'cluster-01')

peers::resource_by_tx(String $class, String $trusted_fact, String $value, String $env = $server_facts['environment'])

The peers::resource_by_tx function.

Returns: Array certnames that match function parameters

Examples

Get an array of nodes with the 'elasticsearch' class assigned that have the value

of 'cluster-01' assigned as the trusted fact extension 'pp_cluster':

$elk_servers = peers::resource_by_tx('elasticsearch', 'pp_cluster', 'cluster-01')

class

Data type: String

The class name associated with the resource.

trusted_fact

Data type: String

The name of the trusted fact extension to match.

value

Data type: String

The value of the trusted fact extension to match.

env

Data type: String

An optional environment to search for matching resources. Defaults to the node environment.

Changelog

All notable changes to this project will be documented in this file.

Release 0.1.0

Features

Bugfixes

Known Issues