Puppet Function: role

Defined in:
modules/wmflib/lib/puppet/functions/role.rb
Function type:
Ruby 4.x API

Overview

role(String $main_role) ⇒ Any

Function: role ( string $role_name [, string $… ] )

Declare the _role variable and if the role class role::$_role is in the scope, include it. This is roughly a shortcut for

$::_role = 'foo/bar' include role::foo::bar

and has the notable advantage over that the syntax is shorter. Also, this function will refuse to run anywhere but at the node scope, thus making any additional role added to a node explicit.

You can only define one role per server. Trying to call this function multiple times will result in a compilation failure.

This function is very useful with our “role” hiera backend if you have global configs that are role-based

Example

node /^wwwd+/ 

role(mediawiki::appserver)  # this will load the role::mediawiki::appserver class
include profile::base::production  #this class will use hiera lookups defined for the role.

node monitoring.local 

role(icinga) #GOOD

node monitoring2.local 

role(icinga)
role(prometheus) #BAD, compilation fails.

Parameters:

Returns:

  • (Any) 


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# File 'modules/wmflib/lib/puppet/functions/role.rb', line 35

Puppet::Functions.create_function(:role) do
  dispatch :main do
    param 'String', :main_role
  end
  def main(main_role)
    scope = closure_scope
    # Check if the function has already been called
    if scope.include? '_role'
      raise Puppet::ParseError, "role() can only be called once per node"
    end
    role = main_role.gsub(/^::/, '')
    # This is where we're going in the future
    # Hack: we transform 'foo::bar' in 'foo/bar' so that it's easy to lookup in hiera
    scope['_role'] = role.gsub(/::/, '/')
    rolename = 'role::' + role
    call_function('include', rolename)
  end
end