simple serverless plugin to notify Slack channel about deployment

package.json

{
    "name": "serverless-aci-slack-plugin",
    "version": "1.0.0",
    "description": "A plugin to notify slack channel when deployment is complete",
    "author": "VB",
    "license": "MIT",
    "dependencies": {
        "superagent": "^3.6.3",
        "superagent-proxy": "^1.0.2",
        "superagent-retry": "^0.6.0"
    }
}

sls_slack.js

'use strict';

const spawnSync = require('child_process').spawnSync;
const request = require('superagent');
require('superagent-proxy')(request);
require('superagent-retry')(request);

class ServerlessPlugin {
  constructor(serverless, options) {
    //console.log('serverless-aci-slack-plugin instantiated');
    this.serverless = serverless;
    this.options = options;
    this.commands = {
      notifySlack: {
        usage: 'Notifies slack channel after deployement',
        lifecycleEvents: [
          'push',
        ],
      }
    };
    this.hooks = { 
        'after:deploy:deploy': this.notifySlack.bind(this)
      };
  }
  notifySlack() {
      //console.log('ready to push data in slack');
      var endPoint ='https://hooks.slack.com/services/<XXXXXXX>';
      var stackName = this.serverless.providers.aws.naming.getStackName(this.options.stage);
      this.endpointInfo(function(reply){
        var text = stackName + " deployed";
        if (reply && reply.length>0) text += ". Service Endpoint: "+reply;
        var notification = {"text": text};

        var publishReq = request.post(endPoint);
        if (process.env.http_proxy) {
            publishReq = publishReq.proxy(process.env.http_proxy);
        } 
        //console.log(notification);
        
        publishReq.retry(3)
            .send(notification)
            .end(function (err, apiResponse) {
                if (err) {
                    console.log(JSON.stringify(err));
                }
        });
      });  
    }
    endpointInfo(cb) {
        const provider = this.serverless.getProvider('aws');
        const stackName = provider.naming.getStackName(this.options.stage);
        return provider
        .request(
            'CloudFormation',
            'describeStacks',
            { StackName: stackName },
            this.options.stage,
            this.options.region 
        )
        .then((result) => {
            const outputs = result.Stacks[0].Outputs;
            const output = outputs.find(entry => entry.OutputKey === 'ServiceEndpoint');
            if (output.OutputValue) {
            this.serverless.cli.log(`ServiceEndpoint: ${output.OutputValue}`);
            cb(`${output.OutputValue}`);
            } else {
            this.serverless.cli.log('ServiceEndpoint: Not Found');
            cb('');
            }
        });
    }
}

module.exports = ServerlessPlugin;