Go beyond the web development with Firebase Cloud Functions

The main thought - developers should be able to enjoy their work.
Assume you’ve started working on development of the web application. By the time you’ve got to the spot of enjoyable developemt, you would have to go through all the complex details of building the basement for your app, taking care about the backend, servers and more...Cloud Functions allows Firebase developers to create a backend without having to worry about servers. During the talk you will learn what's possible with Cloud Functions and how it can be used for many different key use cases for your web app and not only. You'll see real world examples that show how Cloud Functions for Firebase is the programmatic glue that allows you to extend and connect Firebase products and cloud services.

Transcript

1. Go beyond web development with Firebase Cloud Functions Sofia Huts Software Engineer @ JustAnswer Manager @ GDG Lviv
8. https://firebase.google.com/
9. https://firebase.google.com/
10. Platform-as-a-Service (PaaS)
11. CLIENT WEB SERVER DATABASE
12. CLIENT WEB SERVER DATABASE
13. CLIENT WEB SERVER DATABASE
14. CLIENT WEB SERVER DATABASE
15. WEB SERVER DATABASE CLIENTS
19. But what if I want to.. • synchronize data from another source, outside the database • send an email or push notification based on changes that happened in database • perform heavy operations (e.g. image resizing, video transcoding) • expose HTTP endpoints
20. Cloud functions for Firebase
21. App + Firebase SDK Firebase Cloud Functions Database Storage
22. Event driven model Function triggered Event emitted Your code executed
23. In other words...all you know tooth fairy abracadabra result Action / trigger / event
24. • Run in serverless environment • Isolated backend code pieces as “microservice” • Autoscales up on load, and down to zero • Node JS code
25. But I am a mobile developer
26. Triggers HTTP Firebase real-time database / firestore Firebase authentication Firebase analytics / crashlytics Cloud pub / sub Cloud storage HTTP
27. What can I do with it?
28. Notify users when something interesting happens https://firebase.google.com/docs/functions/use-cases
29. Post GitHub commits to a workgroup chat room in Slack https://firebase.google.com/docs/functions/use-cases
30. Let’s code!
31. $ npm install -g firebase-tools $ firebase init functions
32. myproject +- .firebaserc # hidden file which help you quickly switch between | # Firebase projects using ‘firebase use’ | +- firebase.json # describes properties for your project | +- functions/ # directory containing all your functions code | +- package.json # npm package file describing your Cloud Functions | # code and all dependencies | +- index.js # main source file for your Cloud Functions code | +- node_modules/ # directory where your dependencies (declared in # package.json ) are installed
33. const functions = require('firebase-functions'); exports.helloWorld = functions.https.onRequest((req, res) => { res.send('Hello World!'); }); functions/index.js
34. const functions = require('firebase-functions'); exports.helloWorld = functions.https.onRequest((req, res) => { res.send('Hello World!'); }); functions/index.js
35. const functions = require('firebase-functions'); exports.helloWorld = functions.https.onRequest((req, res) => { res.send('Hello World!'); }); functions/index.js
36. const functions = require('firebase-functions'); exports.helloWorld = functions.https.onRequest((req, res) => { res.send('Hello World!'); }); functions/index.js
37. const functions = require('firebase-functions'); exports.helloWorld = functions.https.onRequest((req, res) => { res.send('Hello World!'); }); functions/index.js
38. $ firebase deploy
39. const functions = require('firebase-functions'); exports.lastUpdate = functions.database .ref("/messages/{messageId}").onUpdate(event => { const msg = event.data.val(); msg.lastUpdated = new Date().getTime(); return event.data.adminRef.set(msg); })
40. const functions = require('firebase-functions'); exports.lastUpdate = functions.database .ref("/messages/{messageId}").onUpdate(event => { const msg = event.data.val() msg.lastUpdated = new Date().getTime() return event.data.adminRef.set(msg); })
41. const functions = require('firebase-functions'); exports.lastUpdate = functions.database .ref("/messages/{messageId}").onUpdate(event => { const msg = event.data.val() msg.lastUpdated = new Date().getTime() return event.data.adminRef.set(msg); })
42. const functions = require('firebase-functions'); exports.lastUpdate = functions.database .ref("/messages/{messageId}").onUpdate(event => { const msg = event.data.val() msg.lastUpdated = new Date().getTime() return event.data.adminRef.set(msg); })
43. const functions = require('firebase-functions'); exports.lastUpdate = functions.database .ref("/messages/{messageId}").onUpdate(event => { const msg = event.data.val(); msg.lastUpdated = new Date().getTime() return event.data.adminRef.set(msg); })
44. const functions = require('firebase-functions'); exports.lastUpdate = functions.database .ref("/messages/{messageId}").onUpdate(event => { const msg = event.data.val(); msg.lastUpdated = new Date().getTime(); return event.data.adminRef.set(msg); })
45. Pricing
46. Flame Plan $25/month Spark Plan Free Blaze Plan Pay as you go 125K/month 40K/month 40K/month Google services only 2M/month 400K/month 200K/month 5 GB/month $0.40/million $0.0025/thousand $0.01/thousand $0.12/GB Invocations GB-seconds CPU-seconds Outbound networking Cloud Functions
47. Blaze Plan Calculator https://firebase.google.com/pricing/
48. Blaze Plan Calculator https://firebase.google.com/pricing/
49. Resources Invocation time • 0.7 sec RAM/CPU • 256 MB • 400 MHz Invocations • 10K Compute time (256/1024) x 0.7s = 0.175 GB-seconds per invocation (400/1000) x 0.7s = 0.280 GHz-seconds per invocation 10 000 x 0.175 = 1 175 GB-seconds per month 10 000 x 0.280 = 1 280 GHz-seconds per month Networking 0 GB egress traffic Calculations
50. Billing Metric Gross Value Free Tier Net Value Unit Price Total Price Invocations 10 000 2 000 000 -1 990 000,00 $0.0000004 $0,004 GB-seconds 1 175 400 000 -398 825,00 $0.0000025 $0,0029375 GHz-seconds 1 280 200 000 -198 720,00 $0.00001 $0,0128 Networking 0 5 -5,00 $0.12 $0 Total / Month $0,0197375
51. My own drama
52. https://2017.devfest.cz/
53. https://github.com/gdg-x/hoverboard/tree/hoverboard-v2 @ozasadnyy
54. Firebase console / real-time database
55. Firebase console / real-time database
56. https://github.com/gdg-x/hoverboard/blob/master/scripts/helper/schedule-webworker.js
57. const functions = require('firebase-functions'); const admin = require('firebase-admin'); admin.initializeApp(functions.config().firebase); const scheduleGenerator = require('./schedule-generator-helper.js').generateSchedule; exports.scheduleWrite = functions.database .ref("/schedule").onWrite(event => { const schedulePromise = event.data; const sessionsPromise = admin.database().ref('/sessions').once('value'); const speakersPromise = admin.database().ref('/speakers').once('value'); return generateScheduleOnChange(schedulePromise, sessionsPromise, speakersPromise); });
58. Firebase console / real-time database
59. Drama #2
60. Me Ostap ~ 10 min range time
61. Where the changes I’ve made?
63. My plan was • Start free 300$ trial on GCP • Use pub/sub, so we can trigger function in GCP • In Firebase function publish topic “db-updated” • In Cloud function subscribe for that topic • In Cloud function use Slack webhook to send messages in channel
64. Firebase GCP $300 free credit
65. const functions = require('firebase-functions'); const admin = require('firebase-admin'); exports.scheduleWrite = functions.database .ref("/schedule").onWrite(event => { if (event.auth.admin) { const topic = createTopic('db-changed'); const data = { changedData: event.data._delta, dataPath: '/schedule', database: functions.config().firebase.databaseURL }; publishMessage(topic, data); } }); Only if Admin changes
66. function createTopic(topicName) { const pubsubClient = pubsub(); const topic = pubsubClient.topic(topicName); if (topic) { console.log(`Topic ${topic.name} already exists.`); return topic; } pubsubClient.createTopic(topicName) .then((results) => { const topic = results[0]; console.log(`Topic ${topic.name} created.`); return topic; }); }; const pubsub = require('@google-cloud/pubsub'); Returns topic object if exists Create topic for pub / sub
67. function publishMessage (topic, data) { // Create a publisher for the topic (which can include additional batching configuration) const publisher = topic.publisher(); // Publishes the message as a string, e.g. "Hello, world!" or JSON.stringify(someObject) const dataBuffer = Buffer.from(JSON.stringify(data)); return publisher.publish(dataBuffer) .then((results) => { const messageId = results[0]; console.log(`Message ${messageId} published.`); return messageId; }) .catch((err) => { console.error(`An error occured during publish: ${err}`); }); } Accepts only encoded string Publish to pub / sub
68. Subscribe in GCP
69. Subscribe in GCP exports.subscribe = function subscribe(event, callback) { // The Cloud Pub/Sub Message object. const pubsubMessage = event.data; let data = Buffer.from(pubsubMessage.data, 'base64').toString(); let dataObj = JSON.parse(data); postToSlack(dataObj).then(() => { console.log("Message sent"); }).catch(error => { console.error(error); }); // Don't forget to call the callback. callback(); };
70. Post to Slack const rp = require('request-promise'); function postToSlack(data) { return rp({ method: 'POST', uri: 'https://hooks.slack.com/services/....', body: { text: `:fire: Hello from GCP! New changes arrived in ${data.dataPath}, attachments: [ { title: `Check ${data.database}`, title_link: `${data.database}${data.dataPath}`, text: `${JSON.stringify(data.changedData)}`, color: "#FFC107" } ] }, json: true }); }
71. Post to Slack
73. Google Cloud functions Functions for Firebase == billing billing == SDK SDK
74. const functions = require('firebase-functions'); const admin = require('firebase-admin'); exports.scheduleWrite = functions.database .ref("/schedule").onWrite(event => { if (event.auth.admin) { const topic = createTopic('db-changed'); const data = { changedData: event.data._delta, dataPath: '/schedule', database: functions.config().firebase.databaseURL }; publishMessage(topic, data); } });
75. const functions = require('firebase-functions'); const admin = require('firebase-admin'); exports.scheduleWrite = functions.database .ref("/schedule").onWrite(event => { if (event.auth.admin) { const data = { changedData: event.data._delta, dataPath: '/schedule', database: functions.config().firebase.databaseURL }; postToSlack(data).then(() => { console.log("Message sent"); }).catch(error => { console.error(error); }); } });
76. Drama #3
77. What if I... • Want to have backups of my DB • Don’t wanna enable Blaze plan • My DB is quite small, so I can store data for FREE
78. 5 Gb Free DB Function Storage
79. Let’s code!
80. const functions = require('firebase-functions'); const fse = require('fs-extra'); exports.saveBackup = functions.database.ref('/{node}').onWrite(event => { const maxBackupsCount = 10; const data = event.data.val(); fse.writeJson('/tmp/db-data.json', data) .then(() => { console.log('Successfuly written data to /tmp folder') }) .catch(err => { console.error(err) }); const gcs = require('@google-cloud/storage')(); // Reference to an existing bucket. const bucket = gcs.bucket('<PROJECT_ID>.appspot.com');
81. //Check files count. If get to limit - delete the oldest one bucket.getFiles({ prefix: 'backup/db-data'}).then((result) => { let files = result[0]; if (files.length < maxBackupsCount) { return; } else { // sort by date desc - oldest first const sortedFiles = files.sort(function(a,b) { return new Date(a.metadata.updated) - new Date(b.metadata.updated); }); const fileNameToDelete = sortedFiles[0].name; bucket .file(fileNameToDelete ) .delete() .then(() => { console.log(`${fileNameToDelete} deleted.`); }) .catch(err => { console.error('ERROR:', err); }); } }) .catch(err => console.error(err));
82. //Upload a local file to a new file to be created in bucket. bucket.upload('/tmp/db-data.json', { destination: `/backup/db-data-${new Date().getTime()}.json` }) .then(() => { console.log('Backup was successfuly uploaded!'); }) .catch((err) => { console.error(`Error occured during upload: ${err}`); }); }); //End of saveBackup functions for Firebase
83. To sum up • Let the Cloud functions help you, delegate your work • Try to write optimised function as much as you can (time of execution matters, you pay for it) • Use GSP free tier with 300$ trial, and it will apply to your Firebase project as well • Enjoy this magic!
84. Thank you! Questions? @sophie_h29 sophie.huts.7