lambda-requests 1.5

Use Requests to invoke AWS Lambdas

Lambda-requests use the well familiar requests library to access your HTTP enabled AWS Lambda functions.

Quick start

Installation

pip intall lambda-requests

Usage

>>> import lambda_requests
>>> lr = lambda_requests.Session()
>>> lr.get("http+lambda://flaskexp-test/test/foo")
<Response [200]>

In short, start a lambda_requests.Session() and then access you lambdas by passing http+lambda://{name-of-lambda-function}/… as the uri to the common requests methods such as get, post and the usual parameters such as query strings, form data and so on.

Lambda authorization is configured via boto3, and can be set up using environment variables or a configuration file. Configuration file is recommended. Example credential file ~/.aws/credentials:

[default]
aws_access_key_id =  XXXXXXXXXXXXXXXXXXXX
aws_secret_access_key = XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Similar to authorization, region can be configured either via the environment variable AWS_DEFAULT_REGION, configuration file. Region can also be set on initialization of Session(region=”us-west-2”). Example configuration file ~/.aws/config:

[profile default]
region = us-west-2

The lambdas must support proxy integration, which is used commonly by frameworks such as Zappa, Mangum.

Why

In using REST microservice architecture it is important to be able to conveniently make calls from one service to another. To use this pattern in AWS serverless ecosphere along with Lambda one is practically forced to stand up an API Gateway in front of the lambda. This has several distinct disadvantages, all mostly along the lines of security.

• API Gateway publicly exposes endpoints

• API Gateway uses own authentication / authorization schema. While Lambda already supplies us with IAM.

• Extra dependencies in call chain. While availability is high, latency may still be of concern.

Over all, to reduce exposure of private sub-services, re-use IAM authentication / authorization and reduce latency.

How does its work

Simple, we register a new protocol name with requests and use a lambda specific transport adapter which translates a requests request to lambda invoke compatible with AWS API Gateway simple proxy format.

Limitations

Following functionality has not been tested and is likely to not be functional:

• Cookies

• Basicauth