Being a WordPress developer means that our main programming language is PHP. Which works for building websites but not for running tasks. In this talk I will share my experience using Node.js as a platform to build on. Explaining why I have chosen for Node.js and show you how I used Node.js to build microservices that are supporting my WordPress projects.

1. Marko Heijnen CODEKITCHEN
Node.js to the rescue
Let Node.js do things when WordPress/PHP isn’t enough

2. Marko Heijnen
• Founder of CodeKitchen
• Lead developer of GlotPress
• Core contributor for
WordPress
• Plugin developer
• Organizer for WordCamp
Belgrade 2015
• Technologist

3. Why something else?

4. Yes, you can build almost
everything in WordPress

5. But is that the smart
thing to do?

6. Can you trust on WordPress
to be always stable?

7. This summer I started moving
things away from WordPress

8. WP Central

9. WP Central
• Showing download history
• Showing version usage history
• List all locales and their current state (need update)
• Showing contributors data (currently API only)
• Collects history of locale progress
• Getting checksums for plugins & themes

10. How it works
• A lot of data handling by wp_remote_get
• Scrapping profiles.WordPress.org to read data
• Multiple API calls to api.WordPress.org
• Combine data so it can be presented

11. The problem
• Most things happened through WP Cron
• Some things happens on the front end
• Resulting a load on the webserver that could and
should be prevented

12. New server setup

13. Loadbalancer
Memcached
Elasticsearch
MariaDB
New server setup
Micro
services
Webserver 1
Webserver 2
Thumbor
Public Private

14. Service server
• MariaDB as database
• Memcached as object cache
• Moving to Redis when the PHP7 version is out
• Elasticsearch to make search better/faster

15. The microservices server
• Handles all cronjobs for the network site
• Node.js services running for WP Central
• Like getting checksums for plugins/themes
• Soon merging other WP cronjob calls for getting
all the stats

16. Microservices

17. Microservices
• Microservices are small, autonomous services that
work together
• Small, and Focused on Doing One Thing Well

18. Benefits
• Different services can use different programming
languages
• High level separation
• If WordPress breaks, the services still keep running
• Ease of Deployment
• Scale services that require more resources

19. Benefits
• In general they have an (REST) API
• Reusable
• Other microservices could call the service to run a
task

20. Node.js

21. What is Node.js
• JavaScript platform
• Uses an event-driven, non-blocking I/O model
• Lightweight and efficient
• Ideal for real time application
• Lot’s of modules you can use
• Manage with NPM - https://www.npmjs.org

22. Why to use it
• Internal webserver
• No configuration needed outside it’s code base
• You could use nginx as a proxy but not needed
• You get what you see approach

23. Who is using it
• Netflix

24. Need to know modules
• Express / Restify -> Webserver
• Socket.io -> Real time
• Request -> Doing internet requests
• async -> async calls with callback
• mysql -> MySQL driver with Pool support
• node-cmd -> Command line

25. Checksums for
plugins/themes

26. What is does
• Request checksum of a certain version from a
plugin or theme
• Download the zip and unzips it.
• Reads it in memory and get the checksum per
entry
• After everything is retrieved stores it in MySQL

27. Modules used
• Build in modules
FS
Crypto
• NPM Modules
Express
MySQL
Request
Yauzl for unzipping
• And build a little queue class

28. Calling the API
• http://wpcentral.io/api/checksums/plugin/tabify-
edit-screen/0.8.3 (REST API)
• Calls nginx by IP (10.10.10.10) which handles as a
fallback when the node.js application is down
• nginx calls then internally the node.js application
like proxy_pass http://127.0.0.1:8080

29. API calls
• /plugin/:slug/:version
http://10.10.10.10/checksums/plugin/:slug/:version
http://wpcentral.io/api/checksums/plugin/tabify-
edit-screen/0.8.3
• /theme/:slug/:version
http://10.10.10.10/checksums/theme/:slug/:version
http://wpcentral.io/api/checksums/theme/
twentyfourteen/1.2

30. nginx rules
error_page 404 @404;
error_page 500 @500;
error_page 502 @502;
location @404 {
internal;
add_header Content-Type application/json always;
return 404 '{ "status": "Route Not Found" }';
}
return 500 '{ "status": "Service is down" }';
return 502 '{ "status": "Service is down" }';

31. Going over the code

32. Basic setup
// set variables for environment
var express = require('express'),
app = express(),
mysql = require('mysql'),
request = require('request'),
fs = require('fs'),
crypto = require('crypto'),
yauzl = require("yauzl");

33. MySQL connection
var pool = mysql.createPool({
connectionLimit : 10,
host : ’10.10.10.11’,
user : 'checksums',
password : 'checksums',
database : 'checksums'
});
pool.on('enqueue', function () {
log_error('Waiting for available connection slot');
});

34. Server
app.listen(4000);
app.get( '/plugin/:slug/:version', function(req, res) {
if ( ! queue.add( 'plugin', req.params.slug,
req.params.version, res ) ) {
res.json({
'success': false,
'error': 'Generating checksums’
});
}
});

35. Server 404
app.use(function(req, res, next) {
res.status(404).json({
'success': false,
'error': "Route doesn;'t exist”
});
});

36. Lets check the rest

37. Starting the server
• The default way is: node server.js
• The production server way could be:
pm2 start server.js -u www-data --name “Cool service”

38. The new situation

39. The new situation
• No more unneeded logic in WordPress
• WordPress simple pipes the calls
• Small services that replacing it
• APIs can easily be reused
• Pushing new updates becomes easier
• Currently no caching but easily added

40. Other things you could
use node.js for

41. See my presentation:
Extending WordPress as a pro
Describing an idea of using Socket.io with WordPress

42. Other ideas
• Scheduling tasks or url
calls
• Build a central cache
point for external
sources like getting
tweets
• Real time support
• git2svn sync
• Backup service
• Real time logger
• Perform heavy tasks

43. Thank you for
listening
Questions?
@markoheijnen
markoheijnen.com
codekitchen.eu