Class: ConfigBuilder::Filter::Roles

Inherits:
Object
  • Object
show all
Defined in:
lib/config_builder/filter/roles.rb

Overview

The 'roles' filter adds a mechanism for defining generic VM roles and applying them to VMs.

Defining roles

This filter adds support for a top level roles key. It contains a hash of role names that define a hash containing the role behavior.

@note: The 'vms' field is of type Array, while the 'roles' field is of type Hash. This is because order of declaration matters for the actual VMs, while the order of declaration of roles does not matter.

Examples:

>> run()
=>  {
      'roles' => {
        'webserver' => {
          'synced_folders' => [
            {'host_path' => './www',                'guest_path' => '/var/www'},
            {'host_path' => './webserver-binaries', 'guest_path' => '/opt/webserver-binaries'},
          ]
        },
        'database' => {
          'provisioners' => [
            {'type' => 'puppet', 'manifest' => 'dbserver.pp'},
            {'type' => 'shell',  'path'     => 'scripts/initialize-db.sh'},
          ],
        }
      },
      'vms' => [
        {'name' => 'web',        'roles' => 'webserver'},
        {'name' => 'db',         'roles' => 'database'},
        {'name' => 'standalone', 'roles' => ['webserver', 'database']},
      ],
    }

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#roles ⇒ Object (readonly)

Returns the value of attribute roles.



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# File 'lib/config_builder/filter/roles.rb', line 42

def roles
  @roles
end

Instance Method Details

#filter_vm(old_vm) ⇒ Hash

Returns The filtered VM.

Parameters:

  • old_vm (Hash)

Returns:

  • (Hash) —

    The filtered VM



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# File 'lib/config_builder/filter/roles.rb', line 60

def filter_vm(old_vm)
  role_list  = old_vm.delete('roles')
  node_stack = roles_by_name(role_list)

  node_stack << old_vm

  new_vm = node_stack.inject({}) do |accumulator, role|
    merge_nodes(accumulator, role)
  end

  new_vm
end

#role(name) ⇒ Hash<String, Object>

Fetch the role associated with the given name

Parameters:

  • name (String)

Returns:

  • (Hash<String, Object>) 


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# File 'lib/config_builder/filter/roles.rb', line 78

def role(name)
  if (retval = @roles[name])
    retval
  else
    raise ArgumentError, "Requested role #{name.inspect} is not defined, available roles: #{@roles.keys}."
  end
end

#roles_by_name(name) ⇒ Array<Hash> #roles_by_name(names) ⇒ Array<Hash> #roles_by_name(nothing) ⇒ Array<>

Overloads:

  • #roles_by_name(name) ⇒ Array<Hash>

    Returns An array containing the requested role.

    Parameters:

    • name (String) —

      A single role name

    Returns:

    • (Array<Hash>) —

      An array containing the requested role

  • #roles_by_name(names) ⇒ Array<Hash>

    Returns An array containing all of the requested roles in the order requested.

    Parameters:

    • names (Array<String>) —

      A list of role names

    Returns:

    • (Array<Hash>) —

      An array containing all of the requested roles in the order requested.

  • #roles_by_name(nothing) ⇒ Array<>

    Returns An empty array.

    Parameters:

    • nothing (NilClass) —

      nil

    Returns:

    • (Array<>) —

      An empty array

Returns:

  • (Array) 


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# File 'lib/config_builder/filter/roles.rb', line 100

def roles_by_name(field)

  case field
  when Array    then names = field
  when String   then names = [field]
  when NilClass then names = []
  end

  names.map { |name| role(name) }
end

#run ⇒ Object 



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# File 'lib/config_builder/filter/roles.rb', line 50

def run
  return @root_config if @vms.nil?

  @root_config['vms'] = @vms.map { |vm_hash| filter_vm(vm_hash) }
  @root_config
end

#set_config(root_config) ⇒ Object 



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# File 'lib/config_builder/filter/roles.rb', line 44

def set_config(root_config)
  @root_config = root_config
  @roles       = @root_config.delete('roles')
  @vms         = @root_config.delete('vms')
end