generate_graph.py

# ex: python generate_graph.py | dot -Tpng -o output_file.png

import yaml

edges = []


def create_edges(stuff, parent):
    if isinstance(stuff, str):
        if parent != stuff:
            edges.append((parent, stuff))
    elif isinstance(stuff, list):
        for item in stuff:
            create_edges(item, parent)
    elif isinstance(stuff, dict):
        for k, v in stuff.items():
            if k == 'description':  # later
                continue
            create_edges(v, k)
            create_edges(k, parent)


def main():
    data = yaml.load(open('gist.yaml'))

    # create edges for Graphviz DOT, will fix later for component notation
    for k, v in data.items():
        if v.get('tree'):
            if len(v['tree']) == 1:
                create_edges(v['tree'], parent=list(v['tree'].keys())[0])
            else:
                create_edges(v['tree'], parent='top')

    print('strict digraph tree {')
    for row in edges:
        print('    {0} -> {1};'.format(*row))
    print('}')


if __name__ == '__main__':
    main()

gist.yaml

Handlers:
  lifecycle: |
    Handlers from roles and tasks are loaded and combined in PlaybookExecutor.run.
    The strategy handles the rest. It tracks the listening and notified handlers lists, determines
    if the handlers notified exist, and executes the handlers at the end of a play or when
    a flush_handlers meta task is provided, and waits on the results.
  notes: |
    This is unused code https://github.com/ansible/ansible/blob/651ea5da446887619f875e354903fe4df27b19f0/lib/ansible/executor/task_queue_manager.py#L229.
    iterator._play.handlers is a list of handler block objects (one per play/role)
    https://github.com/ansible/ansible/blob/651ea5da446887619f875e354903fe4df27b19f0/lib/ansible/plugins/strategy/__init__.py#L834.
    Bug - as of 651ea5da446887619f875e354903fe4df27b19f0 handlers from the play override handlers from roles.
  tree:
    PlaybookCLI:
      PlaybookExecutor_func_run:
        Play_func_compile_roles_handlers:
          description: load role handlers
        Playbook_func__load_playbook_data:
          description: load play handlers
        TaskQueueManager_func_run:
          StrategyModule_func_run:
            StrategyBase_func__execute_meta:
              description: check for flush_handlers
              run_handlers:
                _do_handler_run:
                  _queue_task:
                    TaskExecutor:
                      _execute:
                        description: set ansible_notify for result
                  _wait_on_handler_results:
                    _process_pending_results:
                      description: check for ansible_notify in each result item
                      search_handler_blocks_by_name:
                        Handler_func___init__:
                      Handler_func_notify_host:
            StrategyBase_func_run:
              run_handlers: