feat(parser): add KafkaMskEventModel and KafkaSelfManagedEventModel (#1499)

Co-authored-by: Leandro Damascena <[email protected]>
Co-authored-by: Heitor Lessa <[email protected]>
Co-authored-by: heitorlessa <[email protected]>
Co-authored-by: Release bot <[email protected]>
Co-authored-by: Peter Schutt <[email protected]>
Co-authored-by: Ran Isenberg <[email protected]>
Co-authored-by: Ran Isenberg <[email protected]>

Author: 7 people

CHANGELOG.md

@@ -2393,4 +2393,4 @@
 [v1.0.1]: https://github.com/awslabs/aws-lambda-powertools-python/compare/v1.0.0...v1.0.1
 [v1.0.0]: https://github.com/awslabs/aws-lambda-powertools-python/compare/v0.11.0...v1.0.0
 [v0.11.0]: https://github.com/awslabs/aws-lambda-powertools-python/compare/v0.10.1...v0.11.0
-[v0.10.1]: https://github.com/awslabs/aws-lambda-powertools-python/compare/v0.10.0...v0.10.1
+[v0.10.1]: https://github.com/awslabs/aws-lambda-powertools-python/compare/v0.10.0...v0.10.1

aws_lambda_powertools/shared/functions.py

@@ -1,5 +1,10 @@
+import base64
+import logging
+from binascii import Error as BinAsciiError
 from typing import Optional, Union
 
+logger = logging.getLogger(__name__)
+
 
 def strtobool(value: str) -> bool:
     """Convert a string representation of truth to True or False.
@@ -58,3 +63,18 @@ def resolve_env_var_choice(
         resolved choice as either bool or environment value
     """
     return choice if choice is not None else env
+
+
+def base64_decode(value: str) -> bytes:
+    try:
+        logger.debug("Decoding base64 Kafka record item before parsing")
+        return base64.b64decode(value)
+    except (BinAsciiError, TypeError):
+        raise ValueError("base64 decode failed")
+
+
+def bytes_to_string(value: bytes) -> str:
+    try:
+        return value.decode("utf-8")
+    except (BinAsciiError, TypeError):
+        raise ValueError("base64 UTF-8 decode failed")

aws_lambda_powertools/utilities/data_classes/kafka_event.py

@@ -85,10 +85,11 @@ def get_header_value(
 
 
 class KafkaEvent(DictWrapper):
-    """Self-managed Apache Kafka event trigger
+    """Self-managed or MSK Apache Kafka event trigger
     Documentation:
     --------------
     - https://docs.aws.amazon.com/lambda/latest/dg/with-kafka.html
+    - https://docs.aws.amazon.com/lambda/latest/dg/with-msk.html
     """
 
     @property
@@ -98,7 +99,7 @@ def event_source(self) -> str:
 
     @property
     def event_source_arn(self) -> Optional[str]:
-        """The AWS service ARN from which the Kafka event record originated."""
+        """The AWS service ARN from which the Kafka event record originated, mandatory for AWS MSK."""
         return self.get("eventSourceArn")
 
     @property

aws_lambda_powertools/utilities/parser/envelopes/__init__.py

@@ -4,6 +4,7 @@
 from .cloudwatch import CloudWatchLogsEnvelope
 from .dynamodb import DynamoDBStreamEnvelope
 from .event_bridge import EventBridgeEnvelope
+from .kafka import KafkaEnvelope
 from .kinesis import KinesisDataStreamEnvelope
 from .lambda_function_url import LambdaFunctionUrlEnvelope
 from .sns import SnsEnvelope, SnsSqsEnvelope
@@ -20,5 +21,6 @@
     "SnsEnvelope",
     "SnsSqsEnvelope",
     "SqsEnvelope",
+    "KafkaEnvelope",
     "BaseEnvelope",
 ]

aws_lambda_powertools/utilities/parser/envelopes/kafka.py

@@ -0,0 +1,44 @@
+import logging
+from typing import Any, Dict, List, Optional, Type, Union, cast
+
+from ..models import KafkaMskEventModel, KafkaSelfManagedEventModel
+from ..types import Model
+from .base import BaseEnvelope
+
+logger = logging.getLogger(__name__)
+
+
+class KafkaEnvelope(BaseEnvelope):
+    """Kafka event envelope to extract data within body key
+    The record's body parameter is a string, though it can also be a JSON encoded string.
+    Regardless of its type it'll be parsed into a BaseModel object.
+
+    Note: Records will be parsed the same way so if model is str,
+    all items in the list will be parsed as str and npt as JSON (and vice versa)
+    """
+
+    def parse(self, data: Optional[Union[Dict[str, Any], Any]], model: Type[Model]) -> List[Optional[Model]]:
+        """Parses data found with model provided
+
+        Parameters
+        ----------
+        data : Dict
+            Lambda event to be parsed
+        model : Type[Model]
+            Data model provided to parse after extracting data using envelope
+
+        Returns
+        -------
+        List
+            List of records parsed with model provided
+        """
+        event_source = cast(dict, data).get("eventSource")
+        model_parse_event = KafkaMskEventModel if event_source == "aws:kafka" else KafkaSelfManagedEventModel
+
+        logger.debug(f"Parsing incoming data with Kafka event model {model_parse_event}")
+        parsed_envelope = model_parse_event.parse_obj(data)
+        logger.debug(f"Parsing Kafka event records in `value` with {model}")
+        ret_list = []
+        for records in parsed_envelope.records.values():
+            ret_list += [self._parse(data=record.value, model=model) for record in records]
+        return ret_list

aws_lambda_powertools/utilities/parser/models/__init__.py

@@ -17,6 +17,7 @@
 from .cloudwatch import CloudWatchLogsData, CloudWatchLogsDecode, CloudWatchLogsLogEvent, CloudWatchLogsModel
 from .dynamodb import DynamoDBStreamChangedRecordModel, DynamoDBStreamModel, DynamoDBStreamRecordModel
 from .event_bridge import EventBridgeModel
+from .kafka import KafkaBaseEventModel, KafkaMskEventModel, KafkaRecordModel, KafkaSelfManagedEventModel
 from .kinesis import KinesisDataStreamModel, KinesisDataStreamRecord, KinesisDataStreamRecordPayload
 from .lambda_function_url import LambdaFunctionUrlModel
 from .s3 import S3Model, S3RecordModel
@@ -98,4 +99,8 @@
     "APIGatewayEventRequestContext",
     "APIGatewayEventAuthorizer",
     "APIGatewayEventIdentity",
+    "KafkaSelfManagedEventModel",
+    "KafkaRecordModel",
+    "KafkaMskEventModel",
+    "KafkaBaseEventModel",
 ]

aws_lambda_powertools/utilities/parser/models/kafka.py

@@ -0,0 +1,65 @@
+from datetime import datetime
+from typing import Dict, List, Type, Union
+
+from pydantic import BaseModel, validator
+
+from aws_lambda_powertools.shared.functions import base64_decode, bytes_to_string
+from aws_lambda_powertools.utilities.parser.types import Literal
+
+SERVERS_DELIMITER = ","
+
+
+class KafkaRecordModel(BaseModel):
+    topic: str
+    partition: int
+    offset: int
+    timestamp: datetime
+    timestampType: str
+    key: bytes
+    value: Union[str, Type[BaseModel]]
+    headers: List[Dict[str, bytes]]
+
+    # validators
+    _decode_key = validator("key", allow_reuse=True)(base64_decode)
+
+    @validator("value", pre=True, allow_reuse=True)
+    def data_base64_decode(cls, value):
+        as_bytes = base64_decode(value)
+        return bytes_to_string(as_bytes)
+
+    @validator("headers", pre=True, allow_reuse=True)
+    def decode_headers_list(cls, value):
+        for header in value:
+            for key, values in header.items():
+                header[key] = bytes(values)
+        return value
+
+
+class KafkaBaseEventModel(BaseModel):
+    bootstrapServers: List[str]
+    records: Dict[str, List[KafkaRecordModel]]
+
+    @validator("bootstrapServers", pre=True, allow_reuse=True)
+    def split_servers(cls, value):
+        return None if not value else value.split(SERVERS_DELIMITER)
+
+
+class KafkaSelfManagedEventModel(KafkaBaseEventModel):
+    """Self-managed Apache Kafka event trigger
+    Documentation:
+    --------------
+    - https://docs.aws.amazon.com/lambda/latest/dg/with-kafka.html
+    """
+
+    eventSource: Literal["aws:SelfManagedKafka"]
+
+
+class KafkaMskEventModel(KafkaBaseEventModel):
+    """Fully-managed AWS Apache Kafka event trigger
+    Documentation:
+    --------------
+    - https://docs.aws.amazon.com/lambda/latest/dg/with-msk.html
+    """
+
+    eventSource: Literal["aws:kafka"]
+    eventSourceArn: str

docs/utilities/parser.md

@@ -168,6 +168,8 @@ Parser comes with the following built-in models:
 | **APIGatewayProxyEventModel**   | Lambda Event Source payload for Amazon API Gateway                 |
 | **APIGatewayProxyEventV2Model** | Lambda Event Source payload for Amazon API Gateway v2 payload      |
 | **LambdaFunctionUrlModel**      | Lambda Event Source payload for Lambda Function URL payload        |
+| **KafkaSelfManagedEventModel**  | Lambda Event Source payload for self managed Kafka payload         |
+| **KafkaMskEventModel**          | Lambda Event Source payload for AWS MSK payload                    |
 
 ### extending built-in models
 
@@ -308,6 +310,7 @@ Parser comes with the following built-in envelopes, where `Model` in the return
 | **ApiGatewayEnvelope**        | 1. Parses data using `APIGatewayProxyEventModel`. <br/> 2. Parses `body` key using your model and returns it.                                                                                               | `Model`                            |
 | **ApiGatewayV2Envelope**      | 1. Parses data using `APIGatewayProxyEventV2Model`. <br/> 2. Parses `body` key using your model and returns it.                                                                                             | `Model`                            |
 | **LambdaFunctionUrlEnvelope** | 1. Parses data using `LambdaFunctionUrlModel`. <br/> 2. Parses `body` key using your model and returns it.                                                                                                  | `Model`                            |
+| **KafkaEnvelope**             | 1. Parses data using `KafkaRecordModel`. <br/> 2. Parses `value` key using your model and returns it.                                                                                                       | `Model`                            |
 
 ### Bringing your own envelope
 

tests/events/kafkaEventSelfManaged.json

@@ -1,5 +1,5 @@
 {
-  "eventSource":"aws:aws:SelfManagedKafka",
+  "eventSource":"aws:SelfManagedKafka",
   "bootstrapServers":"b-2.demo-cluster-1.a1bcde.c1.kafka.us-east-1.amazonaws.com:9092,b-1.demo-cluster-1.a1bcde.c1.kafka.us-east-1.amazonaws.com:9092",
   "records":{
      "mytopic-0":[

tests/functional/parser/schemas.py

@@ -91,3 +91,7 @@ class MyApiGatewayBusiness(BaseModel):
 class MyALambdaFuncUrlBusiness(BaseModel):
     message: str
     username: str
+
+
+class MyLambdaKafkaBusiness(BaseModel):
+    key: str