Infura Proxy Service

The Infura Proxy Service demonstrates how to build a caching layer for an Ethereum application - and makes it super easy to implement!

Why

Blockchains hold large amounts of data. Service providers like Infura help developers access that data. Browsers can directly request from Inufra, but this leads to higher costs, due to the significant request traffic generated from each user.

How

The Infura Proxy Service acts as a caching layer between Frontend Applications and Infura Service endpoints.

Install:

[Docker](https://www.docker.com/)

[Node v10.X](https://nodejs.org/en/)

[Npm](https://docs.npmjs.com/getting-started/installing-node)
[Yarn](https://classic.yarnpkg.com/en/docs/install/#mac-stable)

$ git clone https://github.com/kamescg/infura-proxy-service docker-express-postgresql-react-starter
$ cd infura-proxy-service
$ npm install || yarn

Running the app:

First Time:

Builds the app and starts all the containers

$ bash run.sh build

Running:

Runs all the containers

$ bash run.sh run

Note: Example .env file located at "./server/.env.sample

Run Dev Server

Runs the database container and one app instance

$ bash run.sh dev

---

Deploying to Digital Ocean

You only need to run three commands on the droplet you create

You will need at least 1GB box (postgres needs at least 1GB to handle 3 connections)

I suggest a Ubuntu 16.04x64 box (1GB/1CPU, 30GB SSD, 2TB Transfer)

$ git clone https://github.com/rapid-eth/infura-proxy-service.git app
$ cd app
$ bash deploy.sh

Usage

START

$ docker-compose up

STOP

$ docker-compose down

Docker will initialize 2 services:

• PostgreSQL Database
• pgAdmin (PostgreSQL Tool)

The services will be initialized using parameters included in the .env file.

• PostgreSQL: `http://localhost:3131/
  • username: infura
  • password: infura
• pgAdmin: http://127.0.0.1:5050/
  • username: infura
  • password: infura

The pgAdmin dashboard requires authentication with PostgreSQL Database.

Click Add New Server and enter the following details

• Name: infura // Recommended Name
• Host name/Address: postgres
• Port: 5432
• username: infura
• password: infura

Overview

The Infura Proxy Service provides a data caching layer that lives between a frontend application and Infura endpoints. By routing requests via a proxy service developers/businesses can better manage costs and even also gain insights into what data is actually being requested by users. Often times the same blockchain data is requested 10's, 100's and likely 1,000's of times before it's "stale" or no longer important state.

The infura-proxy-service is a basic implementation which demonstrates how to cache transaction and receipt requests made from a frontend application to a blockchain node service provider - in this instance, that node provider is Infura.

Models

The infura-proxy-service repo includes several core models for storing common blockchain data.

• Block
• Transaction
• Receipt
• ENS

Each model matches the data structure of succesful JSON-RPC data calls associated with "GET_TRANSACTION", "GET_RECEIPT"

In addition to the core (Block, Transaction, Receipt, ENS) database models, smart contact specific database models are created when the server is initialized. By automatically generating models using smart contract artifacts (ABI JSON files) developers can avoid manually creating new Postgres database models for new/existing smart contracts.

Simplifying the process for creating a cahcing servie for specific smart contracts.

Routes

The server is includes 3 core application routes:

• events
• infura
• cache

Events

The events route(s) is a static route, but outputs are determined by the smart contracts provided at server runtime.

• /events
• /event/[INSERT_EVENT_NAME]

Infura

The infura route(s) provide a "direct line" to the Inufra API endpoints. The routes exists primarily for demonstration purposes, but it's also conceivable an application might want to limit data calls to authenicated users. In other words, additional middleware could be added to the express server routes to limit access to the Infura endpoints.

• /block
• /gas
• /transaction/:hash
• /receipt/:hash
• /ens/resolve/:name
• /ens/lookup/:address

Cache

The cache route(s) are similar to several of the infura routes, but instead of directly calling the Infura API endpoints, the database is first queried for the relevant data (transactions and transaction receipts). If the database returns null then an additional request is dispatched to Infura services to retrieve the requested blockchain data. If Infura returns the data, it's passed back to the requesting application and also stored in the caching layer (postgres) for future requests.

• /cache/transaction/:hash
• /cache/receipt/:hash

Troubleshoot

Scan for Existing Postgres Containers lsof -n -i:5432 | grep LISTEN