Class: Ohai::Runner

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

Instance Method Summary collapse

Constructor Details

#initialize(controller, safe_run = false) ⇒ Runner

safe_run: set to true if this runner will run plugins in safe-mode. default false.


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# File 'lib/ohai/runner.rb', line 27

def initialize(controller, safe_run = false)
  @provides_map = controller.provides_map
  @safe_run = safe_run
end

Instance Method Details

#fetch_plugins(attributes) ⇒ Object


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# File 'lib/ohai/runner.rb', line 89

def fetch_plugins(attributes)
  @provides_map.find_closest_providers_for(attributes)
end

#get_cycle(plugins, cycle_start) ⇒ Object

Given a list of plugins and the first plugin in the cycle, returns the list of plugin source files responsible for the cycle. Does not include plugins that aren't a part of the cycle


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# File 'lib/ohai/runner.rb', line 96

def get_cycle(plugins, cycle_start)
  cycle = plugins.drop_while { |plugin| !plugin.eql?(cycle_start) }
  names = []
  cycle.each { |plugin| names << plugin.name }
  names
end

#run_plugin(plugin) ⇒ Object

Runs plugins and any un-run dependencies. If force is set to true, then this plugin and its dependencies will be run even if they have been run before.


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# File 'lib/ohai/runner.rb', line 35

def run_plugin(plugin)
  unless plugin.kind_of?(Ohai::DSL::Plugin)
    raise Ohai::Exceptions::InvalidPlugin, "Invalid plugin #{plugin} (must be an Ohai::DSL::Plugin or subclass)"
  end

  begin
    case plugin.version
    when :version7
      run_v7_plugin(plugin)
    when :version6
      run_v6_plugin(plugin)
    else
      raise Ohai::Exceptions::InvalidPlugin, "Invalid plugin version #{plugin.version} for plugin #{plugin}"
    end
  rescue Ohai::Exceptions::Error
    raise
  rescue Exception,Errno::ENOENT => e
    Ohai::Log.debug("Plugin #{plugin.name} threw exception #{e.inspect} #{e.backtrace.join("\n")}")
  end
end

#run_v6_plugin(plugin) ⇒ Object


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# File 'lib/ohai/runner.rb', line 56

def run_v6_plugin(plugin)
  return true if plugin.has_run?

  @safe_run ? plugin.safe_run : plugin.run
end

#run_v7_plugin(plugin) ⇒ Object


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# File 'lib/ohai/runner.rb', line 62

def run_v7_plugin(plugin)
  visited = [ plugin ]
  while !visited.empty?
    next_plugin = visited.pop

    next if next_plugin.has_run?

    if visited.include?(next_plugin)
      raise Ohai::Exceptions::DependencyCycle, "Dependency cycle detected. Please refer to the following plugins: #{get_cycle(visited, plugin).join(", ") }"
    end

    dependency_providers = fetch_plugins(next_plugin.dependencies)

    # Remove the already ran plugins from dependencies if force is not set
    # Also remove the plugin that we are about to run from dependencies as well.
    dependency_providers.delete_if { |dep_plugin|
      dep_plugin.has_run? || dep_plugin.eql?(next_plugin)
    }

    if dependency_providers.empty?
      @safe_run ? next_plugin.safe_run : next_plugin.run
    else
      visited << next_plugin << dependency_providers.first
    end
  end
end