Chainlink Python Serverless External Adapter Template

This template shows a basic usecase of an external adapter written in Python for the CryptoCompare API. It can be ran locally, in Docker, AWS Lambda, or GCP Functions.

Install

pipenv install

Test

pipenv run pytest

Run with Docker

Build the image

docker build . -t cl-ea

Run the container

docker run -it -p 8080:8080 cl-ea

Run with Serverless

Create the zip

pipenv lock -r > requirements.txt
pipenv run pip install -r requirements.txt -t ./package
pipenv run python -m zipfile -c cl-ea.zip main.py adapter.py bridge.py ./package/*

Install to AWS Lambda

• In Lambda Functions, create function
• On the Create function page:
  • Give the function a name
  • Use Python 3.7 for the runtime
  • Choose an existing role or create a new one
  • Click Create Function
• Under Function code, select "Upload a .zip file" from the Code entry type drop-down
• Click Upload and select the cl-ea.zip file
• Change the Handler to main.lambda_handler
• Save

To Set Up an API Gateway

An API Gateway is necessary for the function to be called by external services.

• Click Add Trigger
• Select API Gateway in Trigger configuration
• Under API, click Create an API
• Choose REST API
• Select the security for the API
• Click Add
• Click the API Gateway trigger
• Click the name of the trigger (this is a link, a new window opens)
• Click Integration Request
• Uncheck Use Lamba Proxy integration
• Click OK on the two dialogs
• Return to your function
• Remove the API Gateway and Save
• Click Add Trigger and use the same API Gateway
• Select the deployment stage and security
• Click Add

Install to Google Cloud Funcions

• In Functions, create a new function
• Use HTTP for the Trigger
• Optionally check the box to allow unauthenticated invocations
• Choose ZIP upload under Source Code
• Use Python 3.7 for the runtime
• Click Browse and select the cl-ea.zip file
• Select a Storage Bucket to keep the zip in
• Function to execute: gcs_handler
• Click Create