jeffy 0.1.1

Event and Contract Driven Serverless "Application" Framework

Jeffy(Beta)

Description

Event and Contract Driven Serverless "Application" Framework. Utilities for Lambda functions to make it easy to develop serverless applications.

Install

$ pip install jeffy

Features

Logger

Jeffy logger automatically inject some Lambda context infomation.

from jeffy.framework import setup
app = setup()

def handler(event, context):
    app.logger.info({"foo":"bar"})

Output in CloudWatchLogs

{
   "message": {
       "foo":"bar","item":"aa"
    },
   "aws_region":"us-east-1",
   "function_name":"jeffy-dev-hello",
   "function_version":"$LATEST",
   "function_memory_size":"1024",
   "log_group_name":"/aws/lambda/jeffy-dev-hello",
   "log_stream_name":"2020/01/21/[$LATEST]d7729c0ea59a4939abb51180cda859bf",
   "correlation_id":"f79759e3-0e37-4137-b536-ee9a94cd4f52"
}

You can inject some infomation you want to output with using setup method.

from jeffy.framework import setup
app = setup()

app.logger.setup({
   "username":"user1",
   "email":"[e-mail]"
})

def handler(event, context):
    app.logger.info({"foo":"bar"})

Output in CloudWatchLogs

{
   "message": {
       "foo":"bar","item":"aa"
    },
   "username":"user1",
   "email":"[e-mail]",
   "aws_region":"us-east-1",
   "function_name":"jeffy-dev-hello",
   "function_version":"$LATEST",
   "function_memory_size":"1024",
   "log_group_name":"/aws/lambda/jeffy-dev-hello",
   "log_stream_name":"2020/01/21/[$LATEST]d7729c0ea59a4939abb51180cda859bf",
   "correlation_id":"f79759e3-0e37-4137-b536-ee9a94cd4f52"
}

auth_logging decorator allows you to output event, response and stacktrace when you face Exceptions

from jeffy.framework import setup
app = setup()

app.logger.setup({
   "username":"user1",
   "email":"[e-mail]"
})

@app.decorator.auto_logging
def handler(event, context):
    ...

Error output with auto_logging

{
   "error_message": "JSONDecodeError('Expecting value: line 1 column 1 (char 0)')", 
   "stack_trace":"Traceback (most recent call last):
  File '/var/task/jeffy/decorators.py', line 41, in wrapper
    raise e
  File '/var/task/jeffy/decorators.py', line 36, in wrapper
    result = func(event, context)
  File '/var/task/handler.py', line 8, in hello
    json.loads('s')
  File '/var/lang/lib/python3.8/json/__init__.py', line 357, in loads
    return _default_decoder.decode(s)
  File '/var/lang/lib/python3.8/json/decoder.py', line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File '/var/lang/lib/python3.8/json/decoder.py', line 355, in raw_decode
    raise JSONDecodeError('Expecting value', s, err.value) from None",
   "function_name":"jeffy-dev-hello",
   "function_version":"$LATEST",
   "function_memory_size":"1024",
   "log_group_name":"/aws/lambda/jeffy-dev-hello",
   "log_stream_name":"2020/01/21/[$LATEST]90e1f70f6e774e07b681e704646feec0"
}

Decorators

Decorators make simple to implement common lamdba tasks, such as parsing array from Kinesis, SNS, SQS events etc.

Here are provided decorators

• auto_logging: Automatically logs payload event and return value of lambda and when error occurs.

• schedule: Decorator for schedule event. just captures correlation id before main process.

• sqs: Decorator for sqs event. Automaticlly divide"Records" for making it easy to treat it inside main process of Lambda.

• dynamodb_stream: Decorator for Dynamodb stream event. Automatically divide"Records" for making it easy to treat it inside main process of Lambda.

• kinesis_stream: Decorator for Kinesis stream event. Automatically divide"Records" for making it easy to treat it inside main process of Lambda.

• sns: Decorator for SNS event. Automatically divide"Records" for making it easy to treat it inside main process of Lambda.

• s3: Decorator for S3 event. Automatically parse object body stream to Lambda.

• api: Decorator for API Gateway event. Automatically parse string if the"body" can be parsed as Dictionary. Automatically returs 500 error if unexpected error happens.

Using above decorators, inject decorator name to <decorator name> in the folloing example.

from jeffy.framework import setup
app = setup()
@app.decorator.<decorator name>
@app.decorator.sns
@app.decorator.auto_logging
def handler(event, context):
    ...

• json_scheme_validator: Decorator for Json scheme valiidator. Automatically validate body with following json scheme.

from jeffy.framework import setup
app = setup()
@app.decorator.json_scheme_validator(
    json_scheme={
       "type":"object",
       "properties": {
           "message": {"type":"string"}
        }
    }
)
def handler(event, context):
    return event["body"]["foo"]

• api_json_scheme_validator: Decorator for Json scheme valiidator for api. Automatically validate body with following json scheme. Returns 400 error if the validation failes.

from jeffy.framework import setup
app = setup()
@app.decorator.api_json_scheme_validator(
    json_scheme={
       "type":"object",
       "properties": {
           "message": {"type":"string"}
        }
    },
    response_headers={
       "Content-Type":"application/jsoset=utf-8"
    }
)
def handler(event, context):
    return event["body"]["foo"]

CorrelationIDs

CorrelationID is to trace subsequent Lambda functions and services. Jeffy automatically extract correlation IDs and caputure logs from the invocation event.

Also, Jeffy provide boto3 wrapper client to create and inject correlation IDs.

Kinesis Clinent

from jeffy.sdk.kinesis import Kinesis

def handler(event, context):
    Kinesis.put_record(
        stream_name=os.environ["STREAM_NAME"],
        data={"foo": "bar"},
        partition_key="uuid",
        correlation_id=event.get("correlation_id")
    )

SNS Client

from jeffy.sdk.sns import Sns

def handler(event, context):
    Sns.publish(
        topic_arn=os.environ["TOPIC_ARN"],
        message="message",
        subject="subject",
        correlation_id=event.get("correlation_id")
    )

SQS Client

from jeffy.sdk.sqs import Sqs

def handler(event, context):
    Sqs.send_message(
        queue_url=os.environ["QUEUE_URL"],
        message="message",
        correlation_id=event.get("correlation_id")
    )

S3 Client

from jeffy.sdk.s3 import S3

def handler(event, context):
    S3.upload_file(
        file_path="path/to/file", 
        bucket_name=os.environ["BUCKET_NAME"],
        object_name="path/to/object",
        correlation_id=event.get("correlation_id")
    )

Requirements

• Python 3

Development

• Source hosted at GitHub
• Report issues/questions/feature requests on GitHub Issues

Pull requests are very welcome! Make sure your patches are well tested. Ideally create a topic branch for every separate change you make. For example:

1. Fork the repo
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am"Added some feature")
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Authors

• Bought up initial idea by Masashi Terui ([e-mail])
• Created and maintained by Serverless Operations, Inc

License

MIT License (see LICENSE)