Print ansible roles dependencies

ansible-roles-tree.py

#!/usr/bin/env python2
 
import yaml
from sets import Set
from os import path
import sys

roles_dirs = ['roles', '.']

loaded_roles = Set()

def get_tree(role_name):
  if role_name in loaded_roles:
    return role_name
  try:
    dependencies = get_dependencies(role_name)
    if len(dependencies) > 0:
      return {role_name: dependencies}
    else:
      return role_name
  except RoleNotFoundException:
    return "%s (NOT FOUND)" % role_name


def get_dependencies(role_name):
  role_dir = find_role_dir(role_name)
  if role_dir is None:
    raise RoleNotFoundException()
  
  loaded_roles.add(role_name)
  meta_file = path.join(role_dir, 'meta/main.yml')
  if path.isfile(meta_file):
    meta = {}
    with file(meta_file, 'r') as f:
      meta = yaml.load(f)
    if 'dependencies' in meta:
      return [get_tree(normalize_dependency(role)) for role in meta['dependencies'] ]
  return []

def normalize_dependency(role):
  if isinstance(role, basestring):
    return role
  elif 'name' in role:
    return role['name']
  elif 'role' in role:
    return role['role']
  else:
    return role

def find_role_dir(role_name):
  for parent in roles_dirs:
    role_dir = path.join(parent, role_name)
    if path.isdir(role_dir):
      return role_dir
  return None

class RoleNotFoundException(Exception):
  pass

if len(sys.argv) > 1:
  print(yaml.dump(get_tree(sys.argv[1]), default_flow_style=False))
else:
  print('Usage: %s role_name' % sys.argv[0])