Making Consensus API calls to an Ethereum node in Amazon Managed Blockchain (AMB)

Copy the contents of the script that follows and save it to a file on your machine (for example, consensus-ethereum-example.js).

Contents of consensus-ethereum-example.js

const AWS = require('aws-sdk');
const REGION = process.env.AWS_DEFAULT_REGION || 'us-east-1';

async function signedManagedBlockchainRequest(endpoint, credentials, host) {
    const awsRequest = new AWS.HttpRequest(new AWS.Endpoint(endpoint), REGION);
    awsRequest.method = 'GET';
    awsRequest.headers['host'] = host;
    const signer = new AWS.Signers.V4(awsRequest, 'managedblockchain');
    signer.addAuthorization(credentials, new Date());

    return awsRequest
}

/**
 * Sends Consensus API requests to AMB Ethereum node.
 * @param {*} nodeId - Node ID
 * @param {*} consensusApi - Consensus API to invoke, such as "/eth/v1/beacon/genesis".
 * @param {*} credentials - AWS credentials.
 * @returns A promise with invocation result.
 */
async function sendRequest(nodeId, consensusApi, credentials) {
    const host = `${nodeId}.ethereum.managedblockchain.${REGION}.amazonaws.com`
    const endpoint = `https://${host}${consensusApi}`;
    request = await signedManagedBlockchainRequest(endpoint, credentials, host)
    const client = new AWS.HttpClient();
    return  await  new Promise((resolve, reject) => {
        client.handleRequest(request, null, response => {
            let data = []
            response.on('data', chunk => {
                data.push(chunk);
            });
            response.on('end', () => {
            var responseBody = Buffer.concat(data);
                resolve(responseBody.toString('utf8'))
            });
        })
    });
}

const nodeId = process.env.NODE_ID;
new AWS.CredentialProviderChain()
    .resolvePromise()
    .then(credentials => sendRequest(nodeId, '/eth/v1/beacon/states/finalized/root', credentials))
    .then(console.log)
    .catch(err => console.error('ERROR: ' + err))

Run the script to call the Consensus API method over HTTP on your Ethereum node.

NODE_ID=nd-6eaj5va43jggnpxouzp7y47e4y AWS_DEFAULT_REGION=us-east-1 node consensus-ethereum-example.js

Copy the contents of the script that follows and save it to a file on your machine (for example, consensus-ethereum-example.js).

Contents of consensus-ethereum-example.js

const AWS = require('aws-sdk');
const REGION = process.env.AWS_DEFAULT_REGION || 'us-east-1';

function getManagedBlockchainClient(){
    const endpoint = `https://managedblockchain.${REGION}.amazonaws.com`;
    const client = new AWS.ManagedBlockchain();
    client.setEndpoint(endpoint);
    return client;
}

async function getAccessTokenFromManagedBlockChain() {
    const client = getManagedBlockchainClient();
    const accessorType = { AccessorType : "BILLING_TOKEN"};
    const networkType = { NetworkType : "ETHEREUM_MAINNET"};
    const tokenResponse = await new Promise((resolve, reject) => {
        client.createAccessor( accessorType, networkType, (err, data) => {
            if (err) {
                console.error(err);
                reject(err.message);
            }
            else {
		resolve(data);
	    }
        });
    });
    return tokenResponse;
}

async function deleteAccessTokenFromManagedBlockChain(accessorId) {
    const client = getManagedBlockchainClient();
    const id = { AccessorId : accessorId };
    const tokenResponse = await new Promise((resolve, reject) => {
        client.deleteAccessor( id, (err, data) => {
            if (err) {
                console.error(err);
                reject(err.message);
            }
            else resolve(data);
        });
    });
}

function getManagedBlockchainRequest(endpoint, host) {

    const awsRequest = new AWS.HttpRequest(new AWS.Endpoint(endpoint), REGION);
    awsRequest.method = "GET";
    awsRequest.headers['host'] = host;
    awsRequest.headers['Content-Type'] = 'application/json'

    return awsRequest
}

/**
 * Sends Consensus API requests to AMB Ethereum node.
 * @param {*} nodeId - Node ID
 * @param {*} consensusApi - Consensus API to invoke, such as "/eth/v1/beacon/genesis".
 * @param {*} credentials - AWS credentials.
 * @returns A promise with invocation result.
 */
async function sendRequest(nodeId, consensusApi) {
    const token = await getAccessTokenFromManagedBlockChain();

    const host = `${nodeId}.t.ethereum.managedblockchain.${REGION}.amazonaws.com`;
    const endpoint = `https://${host}${consensusApi}?billingtoken=${token.BillingToken}`;
    request = getManagedBlockchainRequest(endpoint, host)
    const client = new AWS.HttpClient();

    const promise =  await  new Promise((resolve, reject) => {
        client.handleRequest(request, null, response => {
            let data = []
            response.on('data', chunk => {
                data.push(chunk);
            });
            response.on('end', () => {
            var responseBody = Buffer.concat(data);
                resolve(responseBody.toString('utf8'))
            });
        })
    });
    deleteAccessTokenFromManagedBlockChain(token.AccessorId);
    return promise;
}

const nodeId = process.env.NODE_ID;
new AWS.CredentialProviderChain()
    .resolvePromise()
    .then(() => sendRequest(nodeId, '/eth/v1/beacon/states/finalized/root'))
    .then(console.log)
    .catch(err => console.error('ERROR: ' + err))

Run the script to call the Consensus API method over HTTP on your Ethereum node.

NODE_ID=nd-6eaj5va43jggnpxouzp7y47e4y AWS_DEFAULT_REGION=us-east-1 node consensus-ethereum-example.js