ec2.py 文件源码

def load_user_data_as_yaml_or_die(ignore_missing=False):
    try:
        data = load_user_data_as_yaml()
    except (ConnectTimeout, ConnectionError):
        die('Could not connect to EC2 metadata service - are we on an EC2 instance?')
    except HTTPError as exc:
        if exc.response.status_code == 404 and ignore_missing:
            return {'TREEHUGGER_APP': 'Missing', 'TREEHUGGER_STAGE': 'Missing'}

        die('Got a {} from the EC2 metadata service when retrieving user data'.format(exc.response.status_code))
    except yaml.error.YAMLError:
        die('Did not find valid YAML in the EC2 user data')

    try:
        return data['treehugger']
    except TypeError:
        die('EC2 user data is not a YAML dictionary')
    except KeyError:
        die('YAML in EC2 user data does not have a key "treehugger"')