Class: MCollective::DDL::AgentDDL
- Defined in:
- lib/mcollective/ddl/agentddl.rb
Overview
A DDL class specific to agent plugins.
A full DDL can be seen below with all the possible bells and whistles present.
metadata :name => “Utilities and Helpers for SimpleRPC Agents”,
:description => "General helpful actions that expose stats and internals to SimpleRPC clients",
:author => "R.I.Pienaar <[email protected]>",
:license => "Apache License, Version 2.0",
:version => "1.0",
:url => "http://marionette-collective.org/",
:timeout => 10
action “get_fact”, :description => “Retrieve a single fact from the fact store” do
display :always
input :fact,
:prompt => "The name of the fact",
:description => "The fact to retrieve",
:type => :string,
:validation => '^[\w\-\.]+$',
:optional => false,
:maxlength => 40
output :fact,
:description => "The name of the fact being returned",
:display_as => "Fact"
output :value,
:description => "The value of the fact",
:display_as => "Value",
:default => ""
summarize do
aggregate summary(:value)
end
end
Instance Attribute Summary
Attributes inherited from Base
#entities, #meta, #pluginname, #plugintype, #requirements, #usage
Instance Method Summary collapse
-
#action(name, input, &block) ⇒ Object
Creates the definition for an action, you can nest input definitions inside the action to attach inputs and validation to the actions.
-
#action_interface(name) ⇒ Object
Returns the interface for a specific action.
-
#actions ⇒ Object
Returns an array of actions this agent support.
-
#aggregate(function, format = {:format => nil}) ⇒ Object
Sets the aggregate array for the given action.
-
#display(pref) ⇒ Object
Sets the display preference to either :ok, :failed, :flatten or :always operates on action level.
-
#initialize(plugin, plugintype = :agent, loadddl = true) ⇒ AgentDDL
constructor
A new instance of AgentDDL.
- #input(argument, properties) ⇒ Object
-
#is_function?(method_name) ⇒ Boolean
Checks if a method name matches a aggregate plugin.
-
#method_missing(name, *args, &block) ⇒ Object
If the method name matches a # aggregate function, we return the function with args as a hash.
-
#summarize(&block) ⇒ Object
Calls the summarize block defined in the ddl.
-
#validate_rpc_request(action, arguments) ⇒ Object
Helper to use the DDL to figure out if the remote call to an agent should be allowed based on action name and inputs.
Methods inherited from Base
#findddlfile, #help, #loadddlfile, #metadata, #output, #requires, #template_for_plugintype, #validate_input_argument, #validate_requirements
Constructor Details
#initialize(plugin, plugintype = :agent, loadddl = true) ⇒ AgentDDL
Returns a new instance of AgentDDL.
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# File 'lib/mcollective/ddl/agentddl.rb', line 40 def initialize(plugin, plugintype=:agent, loadddl=true) @process_aggregate_functions = nil super end |
Dynamic Method Handling
This class handles dynamic methods through the method_missing method
#method_missing(name, *args, &block) ⇒ Object
If the method name matches a # aggregate function, we return the function with args as a hash. This will only be active if the @process_aggregate_functions is set to true which only happens in the #summarize block
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# File 'lib/mcollective/ddl/agentddl.rb', line 134 def method_missing(name, *args, &block) unless @process_aggregate_functions || is_function?(name) raise NoMethodError, "undefined local variable or method `#{name}'", caller end return {:function => name, :args => args} end |
Instance Method Details
#action(name, input, &block) ⇒ Object
Creates the definition for an action, you can nest input definitions inside the action to attach inputs and validation to the actions
action "status", :description => "Restarts a Service" do
display :always
input "service",
:prompt => "Service Action",
:description => "The action to perform",
:type => :list,
:optional => true,
:list => ["start", "stop", "restart", "status"]
output "status",
:description => "The status of the service after the action"
end
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# File 'lib/mcollective/ddl/agentddl.rb', line 111 def action(name, input, &block) raise "Action needs a :description property" unless input.include?(:description) unless @entities.include?(name) @entities[name] = {} @entities[name][:action] = name @entities[name][:input] = {} @entities[name][:output] = {} @entities[name][:display] = :failed @entities[name][:description] = input[:description] end # if a block is passed it might be creating input methods, call it # we set @current_entity so the input block can know what its talking # to, this is probably an epic hack, need to improve. @current_entity = name block.call if block_given? @current_entity = nil end |
#action_interface(name) ⇒ Object
Returns the interface for a specific action
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# File 'lib/mcollective/ddl/agentddl.rb', line 175 def action_interface(name) @entities[name] || {} end |
#actions ⇒ Object
Returns an array of actions this agent support
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# File 'lib/mcollective/ddl/agentddl.rb', line 180 def actions @entities.keys end |
#aggregate(function, format = {:format => nil}) ⇒ Object
Sets the aggregate array for the given action
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# File 'lib/mcollective/ddl/agentddl.rb', line 69 def aggregate(function, format = {:format => nil}) raise(DDLValidationError, "Formats supplied to aggregation functions should be a hash") unless format.is_a?(Hash) raise(DDLValidationError, "Formats supplied to aggregation functions must have a :format key") unless format.keys.include?(:format) raise(DDLValidationError, "Functions supplied to aggregate should be a hash") unless function.is_a?(Hash) unless (function.keys.include?(:args)) && function[:args] raise DDLValidationError, "aggregate method for action '%s' missing a function parameter" % entities[@current_entity][:action] end entities[@current_entity][:aggregate] ||= [] entities[@current_entity][:aggregate] << (format[:format].nil? ? function : function.merge(format)) end |
#display(pref) ⇒ Object
Sets the display preference to either :ok, :failed, :flatten or :always operates on action level
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# File 'lib/mcollective/ddl/agentddl.rb', line 84 def display(pref) # defaults to old behavior, complain if its supplied and invalid unless [:ok, :failed, :flatten, :always].include?(pref) raise "Display preference #{pref} is not valid, should be :ok, :failed, :flatten or :always" end action = @current_entity @entities[action][:display] = pref end |
#input(argument, properties) ⇒ Object
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# File 'lib/mcollective/ddl/agentddl.rb', line 46 def input(argument, properties) raise "Input needs a :optional property" unless properties.include?(:optional) super end |
#is_function?(method_name) ⇒ Boolean
Checks if a method name matches a aggregate plugin. This is used by method missing so that we dont greedily assume that every method_missing call in an agent ddl has hit a aggregate function.
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# File 'lib/mcollective/ddl/agentddl.rb', line 145 def is_function?(method_name) PluginManager.find("aggregate").include?(method_name.to_s) end |
#summarize(&block) ⇒ Object
Calls the summarize block defined in the ddl. Block will not be called if the ddl is getting processed on the server side. This means that aggregate plugins only have to be present on the client side.
The @process_aggregate_functions variable is used by the method_missing block to determine if it should kick in, this way we very tightly control where we activate the method_missing behavior turning it into a noop otherwise to maximise the chance of providing good user feedback
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# File 'lib/mcollective/ddl/agentddl.rb', line 60 def summarize(&block) unless @config.mode == :server @process_aggregate_functions = true block.call @process_aggregate_functions = nil end end |
#validate_rpc_request(action, arguments) ⇒ Object
Helper to use the DDL to figure out if the remote call to an agent should be allowed based on action name and inputs.
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# File 'lib/mcollective/ddl/agentddl.rb', line 151 def validate_rpc_request(action, arguments) # is the action known? unless actions.include?(action) raise DDLValidationError, "Attempted to call action #{action} for #{@pluginname} but it's not declared in the DDL" end input = action_interface(action)[:input] || {} input.keys.each do |key| unless input[key][:optional] unless arguments.keys.include?(key) raise DDLValidationError, "Action #{action} needs a #{key} argument" end end if arguments.keys.include?(key) validate_input_argument(input, key, arguments[key]) end end true end |