lambda_codedeploy-to-slack.js

// Adapted from:
//    AWS cloudwatch-alarm-to-slack blueprint
//    https://gist.github.com/lukehutton/74c47f7fd0dfdf08cc26d6e3403fd61a
//    https://github.com/chizou/codedeploy-slack/blob/master/lambda_function_slack.py

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

var webhookUrl, slackChannel;

webhookUrl = '<WEBHOOK_URL>';
slackChannel = '<SLACK_CHANNEL>';


var postMessage = function(message, callback) {
    var body = JSON.stringify(message);
    var options = url.parse(webhookUrl);
    options.method = 'POST';
    options.headers = {
        'Content-Type': 'application/json',
        'Content-Length': Buffer.byteLength(body),
    };

    var postReq = https.request(options, function(res) {
        var chunks = [];
        res.setEncoding('utf8');
        res.on('data', function(chunk) {
            return chunks.push(chunk);
        });
        res.on('end', function() {
            var body = chunks.join('');
            if (callback) {
                callback({
                    body: body,
                    statusCode: res.statusCode,
                    statusMessage: res.statusMessage
                });
            }
        });
        return res;
    });

    postReq.write(body);
    postReq.end();
};

// Adapted from: http://stackoverflow.com/a/34270811
var humanizeDuration = function (seconds) {
    var levels = [
        [Math.floor(seconds / 31536000), 'years'],
        [Math.floor((seconds % 31536000) / 86400), 'days'],
        [Math.floor(((seconds % 31536000) % 86400) / 3600), 'hours'],
        [Math.floor((((seconds % 31536000) % 86400) % 3600) / 60), 'minutes'],
        [(((seconds % 31536000) % 86400) % 3600) % 60, 'seconds'],
    ];
    var returntext = '';

    for (var i = 0, max = levels.length; i < max; i++) {
        if ( levels[i][0] === 0 ) continue;
        returntext += ' ' + levels[i][0] + ' ' + (levels[i][0] === 1 ? levels[i][1].substr(0, levels[i][1].length-1): levels[i][1]);
    }
    return returntext.trim();
};

var getDeploymentLink = function(region, deploymentId) {
    return util.format("<https://%s.console.aws.amazon.com/codedeploy/home?region=%s#/deployments/%s|%s>",
        region, region, deploymentId, deploymentId);
};

var getDeployMessage = function(message) {
    var slackMessage = {
        channel: slackChannel,
        text: util.format('_%s_ *%s* deployment *%s* for `%s`',
            getDeploymentLink(message["region"], message["deploymentId"]),
            message["deploymentGroupName"],
            message["status"],
            message["applicationName"])
    };
    
    var deploymentOverview = message["deploymentOverview"];
    if (deploymentOverview) {
        deploymentOverview = JSON.parse(deploymentOverview);
        
        var duration = humanizeDuration((Date.parse(message["completeTime"]) - Date.parse(message["createTime"]))/1000);
        var fields = [ {
            title: 'Duration',
            value: duration,
            short: false
        }];
        for (var key in deploymentOverview) {
            fields.push({
                title: key,
                value: deploymentOverview[key],
                short: true
            }); 
        }
        
        slackMessage["attachments"] = [
            {
                title: "Deployment Overview",
                fields: fields
            }
        ];
    }
    
    return slackMessage; 
};

var getDeployInstanceMessage = function(message) {
    return {
        channel: slackChannel,
        text: util.format('_%s_ deployment to instance (%s) *%s*',
            getDeploymentLink(message["region"], message["deploymentId"]),
            message["instanceId"],
            message["instanceStatus"])
    };
};

var processEvent = function(event, context) {
    try {
        console.log("Message received: " + event.Records[0].Sns.Message);
        var message = JSON.parse(event.Records[0].Sns.Message);
    } catch (error) {
        // Ignore non-JSON messages.
        return;
    }
    
    var slackMessage;
    if (message["status"]) {
        slackMessage = getDeployMessage(message);
    } else {
        slackMessage = getDeployInstanceMessage(message);
    }

    console.log(slackMessage);

    postMessage(slackMessage, function(response) {
        if (response.statusCode < 400) {
            console.info('Message posted successfully');
            context.succeed();
        } else if (response.statusCode < 500) {
            console.error("Error posting message to Slack API: " + response.statusCode + " - " + response.statusMessage);
            context.succeed();  // Don't retry because the error is due to a problem with the request
        } else {
            // Let Lambda retry
            context.fail("Server error when processing message: " + response.statusCode + " - " + response.statusMessage);
        }
    });
};


exports.handler = function(event, context) {
    processEvent(event, context);
};