HapiJS: A delightful experience

This talk was given at the MVD-JS (Montevideo JavaScript meetup) by Matias Olivera (@moliveraf) and me (@espinosacurbelo).

Thanks to this amazing people:
- Eran Hammer (@eranhammer) - Hapi creator (http://hueniverse.com/2012/12/20/hapi-a-prologue/ & http://hueniverse.com/2014/08/20/performance-at-rest/)
- Dave Stevens (@shakefon) - Organise the project into plugins (https://medium.com/nerds-zappos/manifests-plugins-and-schemas-organizing-your-hapi-application-68cf316730ef)

Transcript

1. A delightful experience
2. Rodrigo Espinosa @espinosacurbelo Matías Olivera @moliveraf
3. So… what is hapi?
4. –Eran Hammer (hapi creator) “hapi was created around the idea that configuration is better than code, that business logic must be isolated from the transport layer...”
5. Creating a server
6. Create a new server object 1 var Hapi = require('hapi'); 2 3 var server = new Hapi.Server();
7. Then, define a connection 1 var Hapi = require('hapi'); 2 3 var server = new Hapi.Server(); 4 server.connection({ port: 3000 });
8. Specifying the port in the connection 1 var Hapi = require('hapi'); 2 3 var server = new Hapi.Server(); 4 server.connection({ port: 3000 });
9. Starting the server 1 var Hapi = require('hapi'); 2 3 var server = new Hapi.Server(); 4 server.connection({ port: 3000 }); 5 6 server.start(function () { 7 8 console.log('Server running at:', server.info.uri); 9 });
10. Adding routes
11. Adding routes 1 var Hapi = require('hapi'); 2 3 var server = new Hapi.Server(); 4 server.connection({ port: 3000 }); 5 6 server.route({ 7 method: 'GET', 8 path: '/', 9 handler: function (request, reply) { 10 reply('Hello, world!'); 11 } 12 }); 13 14 server.start(function () { 15 16 console.log('Server running at:', server.info.uri); 17 });
12. server.route takes a single configuration object { method: 'GET', path: '/', handler: function (request, reply) { reply('Hello, world!'); } }
13. The HTTP verb you're responding to doesn't dictate the API method to use unlike express app.get(), app.post(), etc.
14. Response with the reply function 1 var handler = function (request, reply) { 2 3 return reply('success'); 4 };
15. Validating with Joi
16. Input validation 1 server.route({ 2 method: 'GET', 3 path: '/hello/{name}', 4 handler: function (request, reply) { 5 reply('Hello ' + request.params.name + '!'); 6 }, 7 config: { 8 validate: { 9 params: { 10 name: Joi.string().min(3).max(10) 11 } 12 } 13 } 14 });
17. Input validation response for /hello/a { "error": "Bad Request", "message": "the length of name must be at least 3 characters long", "statusCode": 400, "validation": { "keys": [ "name" ], "source": "params" } }
18. Query validation 1 server.route({ 2 method: 'GET', 3 path: '/list', 4 handler: function (request, reply) { 5 reply(resources.slice(0, request.query.limit); 6 }, 7 config: { 8 validate: { 9 query: { 10 limit: Joi.number().integer().max(100) 11 } 12 } 13 } 14 });
19. Query validation response for /list?limit=15&offset=15 { "error": "Bad Request", "message": "the key offset is not allowed", "statusCode": 400, "validation": { "keys": [ "offset" ], "source": "query" } }
20. If you validate one key, by default you must validate them all
21. It is also possible to validate incoming headers, with a validate.headers parameter
22. You may also validate the payload data sent to a route, via the validate.payload parameter
23. As in query validation, if you validate one key, you must validate them all
24. Plugin system
25. Simple plugin 1 var myPlugin = { 2 register: function (server, options, next) { 3 next(); 4 } 5 } 6 7 myPlugin.register.attributes = { 8 name: 'myPlugin', 9 version: '1.0.0' 10 };
26. As a external module 1 exports.register = function (server, options, next) { 2 next(); 3 }; 4 5 exports.register.attributes = { 6 pkg: require('./package.json') 7 };
27. Loading a plugin 1 server.register({register: require(‘myplugin')}, 2 function (err) { 3 if (err) { 4 console.error('Failed to load plugin:’, 5 err); 6 } 7 });
28. Loading multiple plugins 1 server.register([ 2 { 3 register: require('myplugin'), 4 options: {} // options for 'myplugin' 5 },{ 6 register: require('yourplugin'), 7 options: {} // options for 'yourplugin' 8 } 9 ], function (err) { 10 if (err) { 11 console.error('Failed to load a plugin:', err); 12 } 13 });
29. How powerful it is?
30. Production ready
31. protection against your process going out of memory
32. event queue delay protection
33. client request timeouts
34. server response timeouts
35. protection against aborted requests
36. built-in request lifecycle logging
37. input validation
38. security headers
39. People who faced it
40. Walmart in Black Friday sales
41. Walmart handle all mobile Black Friday traffic using hapi
42. ~70% of their Black Friday traffic on mobile
43. with about 10 CPU cores and 28Gb RAM
44. Mind blowing traffic going through insignificant computing power (*)
45. (*) “insignificant” by Walmart
46. Composing a server
47. Creating a server 1 var Hapi = require('hapi'); 2 3 var server = new Hapi.Server(); 4 server.connection({ port: 3000 }); 5 6 server.start(function () { 7 8 console.log('Server running at:', server.info.uri); 9 });
48. Composing a server 1 var Glue = require('glue'); 2 var manifest = { 3 connections: [{ 4 port: 80 5 }] 6 }; 7 8 Glue.compose(manifest, function (err, server) { 9 10 server.start(function (err) { 11 12 console.log('Server running at:’, 13 server.info.uri); 14 }); 15 });
49. manifest.json { "server": { "app": { "slogan": "We push the web forward" } }, "connections": [ { "port": 80, "labels": ["web-ui"] }, { "port": 9000, "labels": ["api"] } ] }
50. Composing a server 1 var Glue = require('glue'); 2 3 Glue.compose(require(‘./config/manifest.json'), 4 function (err, server) { 5 6 server.start(function (err) { 7 8 // UI running on port 80, 9 // API running on port 9000 10 }); 11 });
51. Organising a hapi project
52. Organising into Controllers / |_ index.js |_ lib |_ controllers |_ about.js |_ home.js |_ search.js |_ views |_ about.html |_ home.html |_ layout.html |_ search.html
53. lib/controllers/home.js 1 module.exports = function (request, reply) { 2 3 var context = { 4 pageTitle: 'Home Page' 5 }; 6 7 reply.view('home', context); 8 };
54. index.js 1 server.route({ 2 path: '/', 3 method: 'GET', 4 handler: require('./lib/controllers/home') 5 });
55. Simple and manageable pattern, but…
56. Why don’t we modularize the different parts of functionality?
57. Organising into Plugins / |_ index.js |_ lib |_ modules |_ company |_ about.js |_ home.js |_ index.js |_ package.json |_ search |_ index.js |_ package.json |_ search.js |_ templates |_ about.html |_ home.html |_ layout.html |_ search.html
58. lib/modules/company/ index.js 1 exports.register = function (server, options, next) { 2 3 server.route({ 4 path: '/', 5 method: 'GET', 6 handler: require('./home') 7 }); 8 9 server.route({ 10 path: '/about', 11 method: 'GET', 12 handler: require('./about') 13 }); 14 15 next(); 16 }; 17 18 exports.register.attributes = { 19 pkg: require('./package.json') 20 };
59. lib/modules/company/package.json { "name": "exampleCompanySection", "version": "1.0.0" }
60. lib/modules/company/ home.js 1 module.exports = function (request, reply) { 2 3 var context = { 4 pageTitle: 'Home Page' 5 }; 6 7 reply.view('home', context); 8 };
61. manifest.json { "server": { "app": { "slogan": "We push the web forward" } }, "connections": [ { "port": 80, "labels": ["web-ui"] }, { "port": 9000, "labels": ["api"] } ], "plugins": { "./company": null, "./search": null } }
62. index.js 1 var Glue = require('glue'); 2 var manifest = require('./config/manifest.json'); 3 var options = { 4 relativeTo: process.cwd() + '/lib/modules' 5 }; 6 7 Glue.compose(manifest, options, function (err, server) { 8 9 server.start(function (err) { 10 11 // UI running on port 80, 12 // API running on port 9000 13 }); 14 });
63. Thanks.