Chainlink External Adapters (TypeScript)

This repository contains the source code for Chainlink external adapters. If you would like to contribute, please see the Contributing page for more details.

Table of Contents

1. Getting Started
2. How to Run
3. Testing
4. Deployment
5. EA Versioning
6. Advanced Features

Getting Started

Requirements

• Node.js v16
• Yarn

Install

yarn

Installs the dependencies for all workspaces.

Setup

yarn setup

Runs the setup step for all adapters. Typically this step just compiles TypeScript, but may involve other tasks.

Clean

yarn clean

Clears all build files/directories. Useful in case of issues when installing dependencies or running setup.

Folder Structure

╠═.github - scripts automatically ran by the CI/CD workflow
║
╠═.husky - git hooks
║
╠═.vscode - code editor specific configuration
║
╠═.yarn - yarn 2 dependencies
║
╠═grafana - utilities and configurations related to Grafana
║
╚═packages
    ║
    ╠══ composites - adapters composed of multiple other adapters for complex functionality
    ║
    ╠══ core - the internal framework used across all external adapters
    ║
    ╠══ k6 - performance testing scripts and configurations using k6
    ║
    ╠══ non-deployable - adapters that are not meant to be ran independently
    ║
    ╠══ scripts - additional Node.js scripts for mono-repository management
    ║
    ╠══ sources - adapters that read data from a data provider's API.
    ║
    ╚══ targets - adapters that write data to a location, often a blockchain.

How to Run

External adapters should be run as long-lived processes, either directly as HTTP Server, Docker Container, or Single-Command Docker App. Each adapter may have configuration that is required to be supplied through environment variables.

Configuration

There may be required environment variables that must be provided to run an External Adapter. Please see the respective adapter's README for more specific information on the External Adapter that you would like to run.

Every External Adapter has some optional environment variables for customizing behavior and turning on advanced features. The list of all available options can be seen here.

Run as HTTP server

Use the start command while in the directory of the adapter that you would like to run. For example:

cd packages/sources/coingecko
yarn start

Run as Docker Container

1. All of the external-adapters have a service that is created when the repo's docker-compose file is generated.

This can be done by running the following command in the root of the repository (after yarn && yarn setup):

yarn generate:docker-compose

2. Next create a container image. Use the generated docker-compose.generated.yaml file along with docker-compose build.

docker-compose -f docker-compose.generated.yaml build [adapter-name]

Where [adapter-name] is replaced with the following:

Parameter	Description	Options
adapter-name	name of the external adapter package, usually the folder name with -adapter as a suffix	See docker-compose.generated.yaml for list of services that can be used as options

For example the bravenewcoin external adapter uses bravenewcoin-adapter:

docker-compose -f docker-compose.generated.yaml build bravenewcoin-adapter

3. Then run it with:

docker-compose -f docker-compose.generated.yaml run -p 8080:8080 -e API_KEY='YOUR_API_KEY' bravenewcoin-adapter

Environment files can also be passed through a file:

docker run -p 8080:8080 --env-file="~/PATH_TO_ENV" -it proof-of-reserves-adapter:latest

Single-Command Docker App

This command will start all of your external adapters with performance features enabled and with pre-defined metrics charts for each EA on a single server.

The first step will be to load up all of the environment variables that are needed across all of the External Adapters that will be ran. These can either be already be loaded into the environment or supplied to the startup script as a text file. Also make sure that Grafana dependencies are installed.

Starting from the root of the repository:

1. Ensure that the project is setup and that the docker-compose file has been generated

yarn && yarn setup && yarn generate:docker-compose

2. Use the startup script by supplying every External Adapter that you would like to run and monitor.

The adapter will have the format of [[ADAPTER NAME]]-adapter.

For example:

cd grafana && ./scripts/compose.sh coingecko-adapter coinmarketcap-adapter

3. The running services can be found at the following ports:

• External Adapters - search docker-compose.generated.yaml for the name of your EA. The port it is running on will be found as the first number before the colon under ports.

coincodex-adapter:
  image: coincodex-adapter:0.0.4
  ports:
    - 8112:8080 <----------- The first number before the colon here
  build:
    context: ..
    dockerfile: ./Dockerfile
    args:
      location: packages/sources/coincodex
      package: '@chainlink/coincodex-adapter'
    labels:
      com.chainlinklabs.external-adapter-type: sources
  environment:
    - EA_PORT=${EA_PORT}

• Prometheus - http://localhost:9090/graph

• Grafana - http://localhost:3000/

  The default login is:

  • Username: admin
  • Password: admin

Testing

In order to e2e test adapters locally, you may need to set environment variables such as $API_KEY. These can be found in the README.md for every adapter. Integration and unit tests use mocks, so there is no need to set environment variables.

Make sure you run these commands from the ROOT of this monorepo.

# Build all packages
yarn setup

# Run all unit tests
yarn test:unit

# Run all integration tests
yarn test:integration

export adapter=myadapter # Your adapter name, coinmarketcap, coingecko, etc

# Run integration tests for that adapter
yarn test $adapter/test/integration

# Run unit tests for that adapter
yarn test $adapter/test/unit

# Run a specific test for that adapter
yarn test $adapter/test/unit/my-specific-test.test.ts

# Run a tests in watch mode, re-running tests that have code changes or dependency changes in them
yarn test --watch $adapter/test/unit

Deployment

Container Images

Images are being published to Chainlink's public AWS ECR repositories: public.ecr.aws/chainlink/adapters

They can also be found in the public gallery, the registry name is chainlink (e.g. https://gallery.ecr.aws/chainlink/adapters/1forge-adapter).

The External Adapters are being tagged with semantic releases to allow for automated upgrades.

Running from ECR

The EA container image can be download by using the docker pull command. For example:

docker pull public.ecr.aws/chainlink/adapters/1forge-adapter:latest

To run the image use the docker run command. For example:

docker run -p 8080:8080 -e API_KEY='YOUR_API_KEY' public.ecr.aws/chainlink/adapters/1forge-adapter:latest

It can be helpful to pass a text file to the container to handle giving multiple environment variables:

docker run -p 8080:8080 --env-file=[[path to your env file]] public.ecr.aws/chainlink/adapters/1forge-adapter:latest

External Adapters Versioning

For a full rundown on how versioning works, see semver.

What you need to know is that we make releases with the following versioning scheme: major.minor.patch.

• A patch version change usually has small changes/bug fixes. Upgrading/downgrading the patch version number should never break compatibility.
• A minor version change usually adds functionality. Upgrading should never break compatibility, but you might not be able to downgrade the minor version.
• A major version change usually introduces a breaking change. Both upgrading and downgrading the major version number might require additional work. Proceed with caution!

Best practice is to try to always keep it up to date!

Why do the versions jump up sometimes?

Sometimes when looking at the releases for an EA you might see it jumped a version number. For example, the previous release might be 1.2.3 and then the next release is 1.2.5. The reason being is that each week we publish a new release. Whenever we make a change it includes a changeset, which uses versioning semantics above (major, minor, and patch). Sometimes over the course of a given week, more than one changes are included in an adapter, so more than one changeset gets ingested into the release, thus causing the release number to jump. So if a version went from 1.2.3 to 1.2.5, that means two patches were pushed that week.

Advanced Features

Please refer to ea-framework-js docs for topics like performance, rate limiting, caching, overrides and other advanced features.