Definitions

[[TOC]]

A definition is the workflow itself. It's the document that describes exactly what tasks will be performed, and in what order.

Attributes

• name (String) - The name of the definition.
• content (Array) - The process definition.

Dollar notation ${...}

Mastermind scans strings in process definition for ${...} placeholders and substitutes them for fields provided by the job or fields added by providers during the execution of the process. Any field interpolated by ${...} will be the string representation of the value. If the literal value of the field is needed (for instance, if a field holds an array of values), use the $f: notation instead.

Given the job fields:

{
  :name => "Dan Ryan",
  :titles => [ "Future Mayor of Lansing, MI", "Thoulght Leader" ]
}

The following definition...

person :name => "${name}", :titles => "$f:titles"

...gets compiled to:

person :name => "Dan Ryan", :titles => [ "Future Mayor of Lansing, MI", "Thoulght Leader" ]

Example definition

Definition.new(
  :name => "standard syntax",
  :content => %q{
    run_ssh host:     '${host}',
            user:     '${user}',
            key_data: '${key_data}',
            command:  '${command}'
  }
).to_pdef

# => compiled definition
#
# ["define",
#  {"name"=>"watee"},
#  [["run_ssh",
#    {"host"=>"${host}",
#     "user"=>"${user}",
#     "key_data"=>"${key_data}",
#     "command"=>"${command}"},
#    []]]]

The previous example uses Ruby 1.9-style hash syntax. If you prefer the look of the "hash rocket", you are more than welcome to use it instead!

Definition.new(
  :name => "hash rockets",
  :content => %q{
    run_ssh :host     => '${host}', 
            :user     => '${user}', 
            :key_data => '${key_data}', 
            :command  => '${command}'
  }
).to_pdef

# => compiled definition
#
# ["define",
#  {"name"=>"watee"},
#  [["run_ssh",
#    {"host"=>"${host}",
#     "user"=>"${user}",
#     "key_data"=>"${key_data}",
#     "command"=>"${command}"},
#    []]]]

You can even mix in plain old Ruby if you're feeling adventurous!

hosts = %w( host1.example.com host2.example.com host3.example.com )

Definition.new(
  :name => "plain ol' ruby!",
  :content => %q{
    hosts = %w( host1.example.com host2.example.com host3.example.com )
    hosts.each do |host|
      run_ssh :host     => host, 
              :user     => '${user}', 
              :key_data => '${key_data}', 
              :command  => '${command}'
    end
  }
).to_pdef

# Same as:
Definition.new(
  :name => "plain ol' ruby!",
  :content => %q{
    run_ssh :host     => "host1.example.com", 
            :user     => '${user}', 
            :key_data => '${key_data}', 
            :command  => '${command}'
    run_ssh :host     => "host2.example.com", 
            :user     => '${user}', 
            :key_data => '${key_data}', 
            :command  => '${command}'
    run_ssh :host     => "host3.example.com", 
            :user     => '${user}', 
            :key_data => '${key_data}', 
            :command  => '${command}'
  }
).to_pdef

# => compiled definition
#
# ["define",
#  {"name"=>"watee"},
#  [["run_ssh",
#    {"host"=>"host1.example.com",
#     "user"=>"${user}",
#     "key_data"=>"${key_data}",
#     "command"=>"${command}"},
#    []],
#   ["run_ssh",
#    {"host"=>"host2.example.com",
#     "user"=>"${user}",
#     "key_data"=>"${key_data}",
#     "command"=>"${command}"},
#    []],
#   ["run_ssh",
#    {"host"=>"host3.example.com",
#     "user"=>"${user}",
#     "key_data"=>"${key_data}",
#     "command"=>"${command}"},
#    []]]]