Class: Ohai::Loader

Inherits:
Object
  • Object
show all
Defined in:
lib/ohai/loader.rb

Overview

Ohai plugin loader. Finds all the plugins specified in the Ohai.config :plugin_path (supports a single or multiple path setting here), evaluates them and returns plugin objects.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(controller) ⇒ Loader

Returns a new instance of Loader.



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# File 'lib/ohai/loader.rb', line 33

def initialize(controller)
  @controller = controller
  @logger = controller.logger.with_child(subsystem: "loader")
  @v7_plugin_classes = []
end

Instance Attribute Details

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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# File 'lib/ohai/loader.rb', line 31

def logger
  @logger
end

Instance Method Details

#load_additional(from) ⇒ Object

load additional plugins classes from a given directory

Parameters:

  • from (String) —

    path to a directory with additional plugins to load



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# File 'lib/ohai/loader.rb', line 70

def load_additional(from)
  from = [ Ohai.config[:plugin_path], from].flatten
  plugin_files_by_dir(from).collect do |plugin_file|
    logger.trace "Loading additional plugin: #{plugin_file}"
    load_v7_plugin(load_plugin_class(plugin_file))
  end
end

#load_all ⇒ Array<String>

loads all plugin classes

Returns:



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# File 'lib/ohai/loader.rb', line 60

def load_all
  plugin_files_by_dir.each do |plugin_file|
    load_plugin_class(plugin_file)
  end

  collect_v7_plugins
end

#load_plugin(plugin_path) ⇒ Object

Load a specified file as an ohai plugin and creates an instance of it. Not used by ohai itself, but is used in the specs to load plugins for testing

Parameters:



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# File 'lib/ohai/loader.rb', line 83

def load_plugin(plugin_path)
  plugin_class = load_plugin_class(plugin_path)
  return nil unless plugin_class.is_a?(Class)

  if plugin_class < Ohai::DSL::Plugin::VersionVII
    load_v7_plugin(plugin_class)
  else
    raise Exceptions::IllegalPluginDefinition, "cannot create plugin of type #{plugin_class}"
  end
end

#load_plugin_class(plugin_path) ⇒ Object

load an ohai plugin object class from file

Parameters:

  • plugin_path —

    String the path to the ohai plugin

Returns:

  • (Object) —

    class object for the ohai plugin defined in the file



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# File 'lib/ohai/loader.rb', line 98

def load_plugin_class(plugin_path)
  # Read the contents of the plugin to understand if it's a V6 or V7 plugin.
  contents = ""
  begin
    logger.trace("Loading plugin at #{plugin_path}")
    contents << IO.read(plugin_path)
  rescue IOError, Errno::ENOENT
    logger.warn("Unable to open or read plugin at #{plugin_path}")
    return nil
  end

  # We assume that a plugin is a V7 plugin if it contains Ohai.plugin in its contents.
  if contents.include?("Ohai.plugin")
    load_v7_plugin_class(contents, plugin_path)
  else
    raise Exceptions::IllegalPluginDefinition, "[DEPRECATION] Plugin at #{plugin_path}"\
    " is a version 6 plugin. Version 6 plugins are no longer supported by Ohai. This"\
    " plugin will need to be updated to the v7 Ohai plugin format. See"\
    " https://docs.chef.io/ohai_custom.html for v7 syntax."
  end
end

#plugin_files_by_dir(plugin_dir = ) ⇒ Array<String>

Searches all plugin paths and returns an Array of file paths to plugins

Parameters:

  • dir (Array, String) —

    directory/directories to load plugins from

Returns:



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# File 'lib/ohai/loader.rb', line 43

def plugin_files_by_dir(plugin_dir = Ohai.config[:plugin_path])
  Array(plugin_dir).map do |path|
    if Dir.exist?(path)
      Ohai::Log.trace("Searching for Ohai plugins in #{path}")

      escaped = ChefConfig::PathHelper.escape_glob_dir(path)
      Dir[File.join(escaped, "**", "*.rb")]
    else
      Ohai::Log.debug("The plugin path #{path} does not exist. Skipping...")
      []
    end
  end.flatten
end