Go Ethereum

The Go Ethereum provides API and blocks indexer services for interacting with the Ethereum blockchain. The application enables users to retrieve a single block, m limit blocks, and transactions with event logs by REST API. Additionally, the application includes a block indexer service that scans blocks into the database concurrently via Web 3 RPC API, allowing for constant updates to the state of Ethereum blocks.

Installation and Setup

Prerequisite

• Go 1.16+
• Docker, the project is based on docker-compose.yml to boot up all runnable services

How to use

1. Clone the repository to your local machine.
2. Ensure that Docker is installed and running on your machine.
3. Create a .env file and do some settings.

• For example, provide the Ethereum client URL to connect the Ethereum node.
• Please follow the prompt instruction!

make gen.env

4. Run make app.start
5. Test the following API endpoints

• Make sure you have started all services, before sending requests!
• And please wait for a few secs to let the indexer do its job.

# Endpoint: /blocks?limit=n
curl --url http://localhost:8080/blocks
curl --url http://localhost:8080/blocks?limit=5

# Endpoint: /blocks/:id
curl --url http://localhost:8080/blocks/1234..

# Endpoint: /tansaction/:txHash
curl --url http://localhost:8080/transaction/0xf754c..

6. Run make app.stop to clean up the containers

End! To know more about other executable commands, please check out the Makefile.

System design

Architecture

The system consists of the following components:

• API service: Handles API use cases.

  • GET /blocks?limit=n
  • GET /blocks/:id
  • GET /transaction/:txHash

• Ethereum block indexer service: Scan blocks into the database concurrently.

  • Use 4 flags (start, window, end, sleep) to regulate the rate of block scanning.
  • The start flag determines where the block starts.
  • The window flag controls the number of concurrent scans.
  • The end flag is an optional flag to decide if the indexer should keep searching for new blocks.
  • The sleep flag sets the rate of block scan to prevent the services from being throttled or seen as DOS.

• DB Service: Use Postgres as the relational database.

Key Features

• The system is designed as a command line base structure.

  • The http command to run the HTTP server and schema migrations.
  • The index command to run the block indexer service.

• API service is an HTTP service.

  • Mainly based on Gin, HTTP framework and Gorm lib as ORM.

• Ethereum block indexer service:

  • Rely on sync.WaitGroup and goroutine to achieve concurrently scan.
  • Use go-ethereum/ethclient to interact with Web3 API RPC endpoints.
  • RPC endpoints are provided by INFURA.

Contributors

• Weilong Fan (IgnacioFan): developer and maintainer