AWS Lambda function to Slack Channel hookup

snsToSlack.js

var https = require('https');
var util = require('util');

exports.handler = function(event, context) {
    console.log(JSON.stringify(event, null, 2));
    console.log('From SNS:', event.Records[0].Sns.Message);

    var postData = {
        "channel": "#aws-sns",
        "username": "AWS SNS via Lamda :: DevQa Cloud",
        "text": "*" + event.Records[0].Sns.Subject + "*",
        "icon_emoji": ":aws:"
    };

    var message = event.Records[0].Sns.Message;
    var severity = "good";

    var dangerMessages = [
        " but with errors",
        " to RED",
        "During an aborted deployment",
        "Failed to deploy application",
        "Failed to deploy configuration",
        "has a dependent object",
        "is not authorized to perform",
        "Pending to Degraded",
        "Stack deletion failed",
        "Unsuccessful command execution",
        "You do not have permission",
        "Your quota allows for 0 more running instance"];

    var warningMessages = [
        " aborted operation.",
        " to YELLOW",
        "Adding instance ",
        "Degraded to Info",
        "Deleting SNS topic",
        "is currently running under desired capacity",
        "Ok to Info",
        "Ok to Warning",
        "Pending Initialization",
        "Removed instance ",
        "Rollback of environment"        
        ];
    
    for(var dangerMessagesItem in dangerMessages) {
        if (message.indexOf(dangerMessages[dangerMessagesItem]) != -1) {
            severity = "danger";
            break;
        }
    }
    
    // Only check for warning messages if necessary
    if (severity == "good") {
        for(var warningMessagesItem in warningMessages) {
            if (message.indexOf(warningMessages[warningMessagesItem]) != -1) {
                severity = "warning";
                break;
            }
        }        
    }

    postData.attachments = [
        {
            "color": severity, 
            "text": message
        }
    ];

    var options = {
        method: 'POST',
        hostname: 'hooks.slack.com',
        port: 443,
        path: '/services/your-slack-webhook-url-info-goes-here'
    };

    var req = https.request(options, function(res) {
      res.setEncoding('utf8');
      res.on('data', function (chunk) {
        context.done(null);
      });
    });
    
    req.on('error', function(e) {
      console.log('problem with request: ' + e.message);
    });    

    req.write(util.format("%j", postData));
    req.end();
};

Thanks for this! Your newest revision removed all definitions of color, which causes the dreaded "Process exited before completing request" error.

EDIT: Actually it looks like you renamed to severity. So if you change line 65's color to severity, all is good!

Hello and thank you for this. I confirm, that line 65 was causing troubles. Replace color with severity and it should be OK.

Great , after the change of line 65 it works

Sorry for the line 65 typo. Refactor oops! I wish there were Gist notifications. If you post a response to the Medium post I can address issues faster.

Anyone have any idea of how to get it to format nicely into Slack? just comes out as a huge blob of JSON that is hardly readable :(

I had to change the request portion to:

    var payload = 'payload=' + util.format('%j', postData);
    var options = {
        method: 'POST',
        hostname: 'hooks.slack.com',
        port: 443,
        path: '/services',
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded',
          'Content-Length': Buffer.byteLength(payload)
      }
    };

    var req = https.request(options, function(res) {
      res.setEncoding('utf8');
      res.on('data', function (chunk) {
        console.log(`BODY: ${chunk}`);
      });

      res.on('end', function () {
        context.done(null);
      });
    });

    req.on('error', function(e) {
      console.log('problem with request: ' + e.message);
    });    

    req.write(payload);

Can anyone please help me with this script as to how to do I alert particular owners (people) in a channel where messages are posted.

Thanks in advance

@aayushKumarJarvis You can modify line 11 (text: "...") and add @channel or @here, or specific usernames.

customized this script.

• Add reaction words from Elastic Beanstalk
• Enable use mention

https://github.com/morugu/aws-lambda-function-templates/blob/master/sns/sns-to-slack.js

I guess the "message" value has changed from formatted text to json-like string recently.
I had to format the message to get human-readable text in slack:

function toText(obj) {
     var formatted = '';
     Object.keys(obj).forEach(function(key) {
       formatted += key + ': ' + obj[key] + '\n\n'
     });
     return formatted;
}

var message = event.Records[0].Sns.Message;
var messageObj = JSON.parse(message);
var message = toText(messageObj);