/external-adapters-js

Monorepo containing JavaScript implementation of external adapters

Primary LanguageJavaScriptMIT LicenseMIT

Chainlink External Adapters (JavaScript)

This repository contains the source for Chainlink external adapters. Each adapter must document its own required parameters and output format.

Requirements

  • Yarn

Install

yarn

Installs packages for all workspaces.

Test

In order to test adapters locally, you may need to set an $API_KEY environment variable for the given API.

cd $adapter
yarn test

Creating a new external adapter

Run the command below to have the example directory cloned using the name you provide for $adapter:

make new adapter=my-adapter-name

If on a Mac, this requires gnu-sed to be installed and set as the default for the command sed.

Docker

To build a Docker container for a specific $adapter, use the following example:

make docker adapter=bravenewcoin

The naming convention for Docker containers will be $adapter-adapter.

Then run it with:

docker run -p 8080:8080 -e API_KEY='YOUR_API_KEY' -it bravenewcoin-adapter:latest

Serverless

Create the zip:

make zip adapter=bravenewcoin

The zip will be created as ./$adapter/dist/$adapter-adapter.zip.

Install to AWS Lambda

  • In Lambda Functions, create function
  • On the Create function page:
    • Give the function a name
    • Use Node.js 12.x 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 $adapter-adapter.zip file
  • Handler:
    • index.handler (same as index.awsHandlerREST) for REST API Gateways (AWS Lambda default)
    • index.awsHandlerREST for REST API Gateways
    • index.awsHandlerHTTP for HTTP API Gateways
  • Add the environment variable (repeat for all environment variables):
    • Key: API_KEY
    • Value: Your_API_key
  • Save

By default, Lambda functions time out after 3 seconds. You may want to change that to 60s in case an API takes longer than expected to respond.

To Set Up an API Gateway (HTTP API)

If using a HTTP API Gateway, Lambda's built-in Test will fail, but you will be able to externally call the function successfully.

  • Click Add Trigger
  • Select API Gateway in Trigger configuration
  • Under API, click Create an API
  • Choose HTTP API
  • Select the security for the API
  • Click Add

To Set Up an API Gateway (REST API)

If using a REST API Gateway, you will need to disable the Lambda proxy integration for Lambda-based adapter to function.

  • 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 GCP

  • In Functions, create a new function, choose to ZIP upload
  • Select Node.js 10 for the Runtime
  • Click Browse and select the $adapter-adapter.zip file
  • Select a Storage Bucket to keep the zip in
  • Function to execute: gcpHandler
  • Click More, Add variable (repeat for all environment variables)
    • NAME: API_KEY
    • VALUE: Your_API_key