def launch_instance()

in syndicate/connection/ec2_connection.py [0:0]
53 lines of code
15 McCabe index (conditional complexity)

    def launch_instance(self, image_id, instance_type,
                        security_groups_names=None,
                        security_group_ids=None,
                        iam_instance_profile=None,
                        name=None, key_name=None,
                        user_data=None, tags=None,
                        subnet_id=None, availability_zone=None):

        tags = tags or []

        if iam_instance_profile:
            if not iam_instance_profile.get('Arn') \
                    and not iam_instance_profile.get('Name'):
                raise AssertionError('Provided instance profile {0}'
                                     'is not well-formed. '
                                     'Arn or Name nodes required.'
                                     .format(iam_instance_profile))

        if name:
            tags.append({
                'Key': 'Name',
                'Value': name
            })

        instance_parameters = {
            'ImageId': image_id,
            'InstanceType': instance_type,
            'MinCount': 1,
            'MaxCount': 1
        }

        if tags:
            instance_parameters['TagSpecifications'] = [{
                'ResourceType': 'instance',
                'Tags': tags
            }]

        if availability_zone:
            instance_parameters['Placement'] = {
                'AvailabilityZone': availability_zone
            }
        if key_name:
            instance_parameters['KeyName'] = key_name
        if user_data:
            instance_parameters['UserData'] = user_data
        if iam_instance_profile:
            instance_parameters['IamInstanceProfile'] = iam_instance_profile
        if subnet_id:
            instance_parameters['SubnetId'] = subnet_id
        if security_groups_names:
            instance_parameters['SecurityGroups'] = security_groups_names
        if security_group_ids:
            instance_parameters['SecurityGroupIds'] = security_group_ids

        response = self.client.run_instances(**instance_parameters)
        # always launch only one instance
        launched_instances = response['Instances']
        if len(launched_instances) < 1:
            return 'No instances launched'
        else:
            return launched_instances[0]