How to fetch aws ecs container ip address in nodejs project

Question

I have uploaded my API project (Node.js project) to AWS ECS container and my project contains swagger documentation. In swagger I want to indicate the current host Ip address that the API is run on but I cannot find the right code to fetch it. There is a solution for that? since I have managed to implement it on .NetCore API.

How does it looks right now:

Thx in advance.

Answer 1

You can make use of AWS ECS metadata endpoint http://172.17.0.1:51678/v1/metadata from an ECS task to fetch details about the container instance. The details fetched can then be used to get the private/public ip address of the instance. Example:

import http from 'http';
import util from 'util';
import AWS from 'aws-sdk';

export const getIPAddresses = async () => {
  try {
    let options: any = {
      hostname: '172.17.0.1',
      port: 51678,
      path: '/v1/metadata',
      method: 'GET'
    }
    let containerInstanceDetails: any = await httpGet(options);
    containerInstanceDetails = JSON.parse(containerInstanceDetails);
    const cluster = containerInstanceDetails["Cluster"];
    const containerInstanceArn = containerInstanceDetails["ContainerInstanceArn"];
    const containerInstanceUUID = containerInstanceArn.split('/')[2];
    let params: any = {
      cluster: cluster,
      containerInstances: [containerInstanceUUID]
    }

    if (!AWS.config.region) {
      AWS.config.update({
        region: <your_aws_region>
      });
    }

    const ecs = new AWS.ECS({ 'region': <your_aws_region> });
    const ec2 = new AWS.EC2({ 'region': <your_aws_region> });

    const describeContainerInstancesAsync = util.promisify(ecs.describeContainerInstances).bind(ecs);
    const describeInstancesAsync = util.promisify(ec2.describeInstances).bind(ec2);
    let data = await describeContainerInstancesAsync(params);
    const ec2InstanceId = data.containerInstances[0].ec2InstanceId;

    params = {
      InstanceIds: [
        ec2InstanceId
      ]
    }

    data = await describeInstancesAsync(params);
    return [data.Reservations[0].Instances[0].PrivateIpAddress, data.Reservations[0].Instances[0].PublicIpAddress];
  }
  catch(err) {
    console.log(err);
  }
}

async function httpGet(options) {
  return new Promise((resolve, reject) => {
    http.get(options, response => {
      response.setEncoding('utf8');
      response.on('data', data => {
        resolve(data);
      });
    }).on('error', error => {
      reject(error.message);
    });
  });
}