Implements simple microservice for moving data from SendGrid events t…

…o Mixpanel

.gitignore

@@ -1,2 +1,3 @@
 .serverless
+serverless.env.yml
 node_modules

README.md

@@ -0,0 +1,36 @@
+# SendGrid Event Webhook to Mixpanel Lambda Function
+
+A simple lambda function that can be used to transfer SendGrid event data to Mixpanel pings.
+
+## Getting Started
+
+1. To get started, you'll need the [Serverless Framework](https://serverless.com/framework/docs/providers/aws/guide/quick-start/) installed. You'll also need your environment configured with [AWS credentials](https://serverless.com/framework/docs/providers/aws/guide/credentials/).
+
+2. Recommended: Map relevant Mixpanel characteristics to [SendGrid SMTP API unique_args](https://sendgrid.com/docs/API_Reference/SMTP_API/unique_arguments.html) for the emails you are sending through SendGrid.
+
+3. Add the MIXPANEL_TOKEN env var for each environment to `serverless.env.yml`.
+
+``` yml
+  dev:
+    MIXPANEL_TOKEN: "DEV TOKEN"
+  staging:
+    MIXPANEL_TOKEN: "STAGING TOKEN"
+  prod:
+    MIXPANEL_TOKEN: "PROD TOKEN"
+```
+
+4. Deploy
+
+``` sh
+  sls deploy --stage prod
+```
+
+5. [Setup the SendGrid Event Webhook](https://sendgrid.com/docs/API_Reference/Webhooks/event.html) with the lambda endpoint.
+
+```
+  HTTP POST URL
+
+  https://EXAMPLE.execute-api.us-east-1.amazonaws.com/dev/mixpanel_sendgrid_events
+```
+
+6. 🎉 SendGrid event data is in Mixpanel and I don't have to run the webhook through our app!

mpTrackSendGrid.js

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+const serverless = require('serverless-http');
+
+const Mixpanel = require('mixpanel');
+const mixpanel = Mixpanel.init(process.env.MIXPANEL_TOKEN);
+
+function handler(event, context, callback) {
+  let body = JSON.parse(event.body);
+  let eventsTracked = 0;
+
+  body.forEach((sendGridEvent) => {
+    mixpanel.track('SendGrid: ' + sendGridEvent.event, sendGridEvent);
+    eventsTracked += 1;
+  });
+
+  const response = {
+    statusCode: 200,
+    eventsTracked: eventsTracked
+  };
+
+  callback(null, response);
+}
+
+module.exports.mixpanel = mixpanel;
+module.exports.handler = handler;

package.json

@@ -6,11 +6,14 @@
   "author": "Nick Weiland <[email protected]>",
   "license": "MIT",
   "dependencies": {
-    "express": "^4.16.2",
     "mixpanel": "^0.7.0",
     "serverless-http": "^1.5.2"
   },
   "devDependencies": {
-    "serverless-offline": "^3.16.0"
+    "chai": "^4.1.2",
+    "lambda-local": "^1.4.4",
+    "mocha": "^4.0.1",
+    "serverless-offline": "^3.16.0",
+    "sinon": "^4.1.2"
   }
 }

serverless.yml

@@ -6,9 +6,16 @@ provider:
   stage: dev
   region: us-east-1
   profile: weilandia
+  environment:
+    MIXPANEL_TOKEN: ${file(./serverless.env.yml):${self:provider.stage}.MIXPANEL_TOKEN}
 
 functions:
-  app:
-    handler: index.handler
+  trackEvents:
+    handler: mpTrackSendGrid.handler
     events:
-      - http: 'POST /mixpanel_sendgrid_event'
+      - http:
+          path: mixpanel_sendgrid_events
+          method: post
+
+plugins:
+  - serverless-offline

test/mpTrackSendGrid.test.js

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+process.env.MIXPANEL_TOKEN = "test_token";
+const expect = require('chai').expect;
+const sinon = require('sinon');
+
+const lambdaLocal = require('lambda-local');
+const mpTrackSendGrid = require('../mpTrackSendGrid');
+
+let sendGridPayload = {
+  body: JSON.stringify([
+    {
+      "distinct_id": 123,
+      "organization_id": 32,
+      "organization_size": "enterprise",
+      "user_email": "[email protected]",
+      "timestamp": 1508542936,
+      "smtp-id": "<14c5d75ce93.dfd.64b469@ismtpd-555>",
+      "event": "processed",
+      "category": "cat facts",
+      "sg_event_id": "M0KaRo92wGpS1clK5ox6gg==",
+      "sg_message_id": "14c5d75ce93.dfd.64b469.filter0001.16648.5515E0B88.0"
+    },
+    {
+      "distinct_id": 456,
+      "organization_id": 122,
+      "organization_size": "smb",
+      "user_email": "[email protected]",
+      "timestamp": 1508542936,
+      "smtp-id": "<14c5d75ce93.dfd.64b469@ismtpd-555>",
+      "event": "deferred",
+      "category": "cat facts",
+      "sg_event_id": "W5aNQjYjn5JzWnrfQ6tGuw==",
+      "sg_message_id": "14c5d75ce93.dfd.64b469.filter0001.16648.5515E0B88.0",
+      "response": "400 try again later",
+      "attempt": "5"
+    }
+  ])
+};
+
+let res;
+let err;
+let mixpanelSpy;
+
+before(function(cb) {
+  mixpanelSpy = sinon.spy(mpTrackSendGrid.mixpanel, 'track');
+  lambdaLocal.execute({
+    event: sendGridPayload,
+    lambdaFunc: mpTrackSendGrid
+  }).then(function(_res) {
+    res = _res;
+  }).catch(function(_err) {
+    err = _err;
+  });
+
+  cb();
+});
+
+describe('mpTrackSendGrid', function() {
+  it('returns a 200 status', function() {
+    expect(res.statusCode).to.equal(200);
+  });
+
+  it('counts tracked events', function() {
+    expect(res.eventsTracked).to.equal(2);
+  });
+
+  it('asks mixpanel to track the right number of events', function() {
+    expect(mixpanelSpy.callCount).to.equal(res.eventsTracked);
+  });
+
+  it('asks mixpanel to track the right data', function() {
+    let event_1 = JSON.parse(sendGridPayload.body)[0];
+    let args_1 = mixpanelSpy.firstCall.args;
+    let props_1 = args_1[1];
+
+    expect(args_1[0]).to.equal("SendGrid: " + event_1.event);
+    expect(props_1.category).to.equal(event_1.category);
+    expect(props_1.sg_event_id).to.equal(event_1.sg_event_id);
+    expect(props_1.sg_message_id).to.equal(event_1.sg_message_id);
+
+    let event_2 = JSON.parse(sendGridPayload.body)[1];
+    let args_2 = mixpanelSpy.secondCall.args;
+    let props_2 = args_2[1];
+
+    expect(args_2[0]).to.equal("SendGrid: " + event_2.event);
+    expect(props_2.category).to.equal(event_2.category);
+    expect(props_2.sg_event_id).to.equal(event_2.sg_event_id);
+    expect(props_2.sg_message_id).to.equal(event_2.sg_message_id);
+  });
+});