# Copyright 2017-2018 Capital One Services, LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import base64
import copy
import zlib
from .core import EventAction
from c7n import utils
from c7n.exceptions import PolicyValidationError
from c7n.resolver import ValuesFrom
[docs]class BaseNotify(EventAction):
batch_size = 250
[docs] def expand_variables(self, message):
"""expand any variables in the action to_from/cc_from fields.
"""
p = copy.deepcopy(self.data)
if 'to_from' in self.data:
to_from = self.data['to_from'].copy()
to_from['url'] = to_from['url'].format(**message)
if 'expr' in to_from:
to_from['expr'] = to_from['expr'].format(**message)
p.setdefault('to', []).extend(ValuesFrom(to_from, self.manager).get_values())
if 'cc_from' in self.data:
cc_from = self.data['cc_from'].copy()
cc_from['url'] = cc_from['url'].format(**message)
if 'expr' in cc_from:
cc_from['expr'] = cc_from['expr'].format(**message)
p.setdefault('cc', []).extend(ValuesFrom(cc_from, self.manager).get_values())
return p
[docs] def pack(self, message):
dumped = utils.dumps(message)
compressed = zlib.compress(dumped.encode('utf8'))
b64encoded = base64.b64encode(compressed)
return b64encoded.decode('ascii')
[docs]class Notify(BaseNotify):
"""
Flexible notifications require quite a bit of implementation support
on pluggable transports, templates, address resolution, variable
extraction, batch periods, etc.
For expedience and flexibility then, we instead send the data to
an sqs queue, for processing. ie. actual communications can be enabled
with the c7n-mailer tool, found under tools/c7n_mailer.
Attaching additional string message attributes are supported on the SNS
transport, with the exception of the ``mtype`` attribute, which is a
reserved attribute used by Cloud Custodian.
:example:
.. code-block:: yaml
policies:
- name: ec2-bad-instance-kill
resource: ec2
filters:
- Name: bad-instance
actions:
- terminate
- type: notify
to:
- event-user
- resource-creator
- email@address
owner_absent_contact:
- other_email@address
# which template for the email should we use
template: policy-template
transport:
type: sqs
region: us-east-1
queue: xyz
- name: ec2-notify-with-attributes
resource: ec2
filters:
- Name: bad-instance
actions:
- type: notify
to:
- event-user
- resource-creator
- email@address
owner_absent_contact:
- other_email@address
# which template for the email should we use
template: policy-template
transport:
type: sns
region: us-east-1
topic: your-notify-topic
attributes:
attribute_key: attribute_value
attribute_key_2: attribute_value_2
"""
C7N_DATA_MESSAGE = "maidmsg/1.0"
schema_alias = True
schema = {
'type': 'object',
'anyOf': [
{'required': ['type', 'transport', 'to']},
{'required': ['type', 'transport', 'to_from']}],
'properties': {
'type': {'enum': ['notify']},
'to': {'type': 'array', 'items': {'type': 'string'}},
'owner_absent_contact': {'type': 'array', 'items': {'type': 'string'}},
'to_from': ValuesFrom.schema,
'cc': {'type': 'array', 'items': {'type': 'string'}},
'cc_from': ValuesFrom.schema,
'cc_manager': {'type': 'boolean'},
'from': {'type': 'string'},
'subject': {'type': 'string'},
'template': {'type': 'string'},
'transport': {
'oneOf': [
{'type': 'object',
'required': ['type', 'queue'],
'properties': {
'queue': {'type': 'string'},
'type': {'enum': ['sqs']}}},
{'type': 'object',
'required': ['type', 'topic'],
'properties': {
'topic': {'type': 'string'},
'type': {'enum': ['sns']},
'attributes': {'type': 'object'},
}}]
},
'assume_role': {'type': 'boolean'}
}
}
def __init__(self, data=None, manager=None, log_dir=None):
super(Notify, self).__init__(data, manager, log_dir)
self.assume_role = data.get('assume_role', True)
[docs] def validate(self):
if self.data.get('transport', {}).get('type') == 'sns' and \
self.data.get('transport').get('attributes') and \
'mtype' in self.data.get('transport').get('attributes').keys():
raise PolicyValidationError(
"attribute: mtype is a reserved attribute for sns transport")
return self
[docs] def get_permissions(self):
if self.data.get('transport', {}).get('type') == 'sns':
return ('sns:Publish',)
if self.data.get('transport', {'type': 'sqs'}).get('type') == 'sqs':
return ('sqs:SendMessage',)
return ()
[docs] def process(self, resources, event=None):
alias = utils.get_account_alias_from_sts(
utils.local_session(self.manager.session_factory))
message = {
'event': event,
'account_id': self.manager.config.account_id,
'account': alias,
'region': self.manager.config.region,
'execution_id': self.manager.ctx.execution_id,
'execution_start': self.manager.ctx.start_time,
'policy': self.manager.data}
message['action'] = self.expand_variables(message)
for batch in utils.chunks(resources, self.batch_size):
message['resources'] = self.prepare_resources(batch)
receipt = self.send_data_message(message)
self.log.info("sent message:%s policy:%s template:%s count:%s" % (
receipt, self.manager.data['name'],
self.data.get('template', 'default'), len(batch)))
[docs] def prepare_resources(self, resources):
"""Resources preparation for transport.
If we have sensitive or overly large resource metadata we want to
remove or additional serialization we need to perform, this
provides a mechanism.
TODO: consider alternative implementations, at min look at adding
provider as additional discriminator to resource type. One alternative
would be dynamically adjusting buffer size based on underlying
transport.
"""
handler = getattr(self, "prepare_%s" % (
self.manager.type.replace('-', '_')),
None)
if handler is None:
return resources
return handler(resources)
[docs] def prepare_launch_config(self, resources):
for r in resources:
r.pop('UserData', None)
return resources
[docs] def prepare_asg(self, resources):
for r in resources:
if 'c7n:user-data' in r:
r.pop('c7n:user-data', None)
return resources
[docs] def prepare_ec2(self, resources):
for r in resources:
if 'c7n:user-data' in r:
r.pop('c7n:user-data')
return resources
[docs] def send_data_message(self, message):
if self.data['transport']['type'] == 'sqs':
return self.send_sqs(message)
elif self.data['transport']['type'] == 'sns':
return self.send_sns(message)
[docs] def send_sns(self, message):
topic = self.data['transport']['topic'].format(**message)
user_attributes = self.data['transport'].get('attributes')
if topic.startswith('arn:'):
region = region = topic.split(':', 5)[3]
topic_arn = topic
else:
region = message['region']
topic_arn = utils.generate_arn(
service='sns', resource=topic,
account_id=message['account_id'],
region=message['region'])
client = self.manager.session_factory(
region=region, assume=self.assume_role).client('sns')
attrs = {
'mtype': {
'DataType': 'String',
'StringValue': self.C7N_DATA_MESSAGE,
},
}
if user_attributes:
for k, v in user_attributes.items():
if k != 'mtype':
attrs[k] = {'DataType': 'String', 'StringValue': v}
client.publish(
TopicArn=topic_arn,
Message=self.pack(message),
MessageAttributes=attrs
)
[docs] def send_sqs(self, message):
queue = self.data['transport']['queue'].format(**message)
if queue.startswith('https://queue.amazonaws.com'):
region = 'us-east-1'
queue_url = queue
elif 'queue.amazonaws.com' in queue:
region = queue[len('https://'):].split('.', 1)[0]
queue_url = queue
elif queue.startswith('https://sqs.'):
region = queue.split('.', 2)[1]
queue_url = queue
elif queue.startswith('arn:'):
queue_arn_split = queue.split(':', 5)
region = queue_arn_split[3]
owner_id = queue_arn_split[4]
queue_name = queue_arn_split[5]
queue_url = "https://sqs.%s.amazonaws.com/%s/%s" % (
region, owner_id, queue_name)
else:
region = self.manager.config.region
owner_id = self.manager.config.account_id
queue_name = queue
queue_url = "https://sqs.%s.amazonaws.com/%s/%s" % (
region, owner_id, queue_name)
client = self.manager.session_factory(
region=region, assume=self.assume_role).client('sqs')
attrs = {
'mtype': {
'DataType': 'String',
'StringValue': self.C7N_DATA_MESSAGE,
},
}
result = client.send_message(
QueueUrl=queue_url,
MessageBody=self.pack(message),
MessageAttributes=attrs)
return result['MessageId']