Creating a Varnish Load Balancer for Opsworks

Posted on Fri 15 January 2016 in aws • Tagged with scaling, infrastructure, opsworks, varnish, chef

Varnish is an amazing platform -- it can easily help you handle 100x traffic and is easy to add to your existing frontend or API layer with little to no change to your app.

Here we'll go over some neat tricks leveraging chef, the AWS Opsworks API and the opsworks configure lifecycle event to create a lighting fast load balancer & reverse proxy that automatically updates itself.

Setup

  1. Create a new varnish layer that installs the varnish and jq packages

  2. Activate custom cookbooks. It's easiest to just use s3 deployments so you don't need a separate git repo.

The varnish::backends recipe …

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Wordpress Cron on Opsworks

Posted on Thu 27 August 2015 in aws • Tagged with opsworks, chef

By default Wordpress uses it's own pseudo-cron which triggers with every request. Obviously this is wasteful since (a) the queue needs to be inspected with every GET and (b) jobs like publishing articles will interfere with serving content.

Some suggest calling the wp-cron.php GET request with curl in a cron like this

* * * * * curl http://www.mysite.com/wp-cron.php

but that's sub-optimal since it needlessly ties up a worker during the cron execution.

If you're using chef or Opsworks, here's a tidy way to install the system cron to execute without interfering with your webserver.

First, disable the Wordpress …

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Opsworks -- Quickly Listing Hosts on the Command Line

Posted on Tue 11 August 2015 in aws • Tagged with aws, opsworks, cli

Here's a great example of using the aws-cli to speed up your life. Uses jq and aws-cli

  # bash / zsh function
  function opsworks-hosts-prod () {
    aws opsworks describe-instances --stack-id=fffff-fffff-ffff-fff-fffffff | jq '.Instances[].PublicDns' | grep -v null | sed s/\"//g
  }
  # usage
  $ opsworks-hosts-prod
  XXXXX.compute-1.amazonaws.com
  XXXXX.compute-1.amazonaws.com
  XXXXX.compute-1.amazonaws.com
  XXXXX.compute-1.amazonaws.com
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Opsworks before-migrate.rb

Posted on Tue 09 June 2015 in aws • Tagged with chef, opsworks, aws, devops

Opsworks is a convenient, powerful and free service provided by AWS to simplify the management of EC2 nodes.  The real power of the system is exposed through customizing various stages of the instance lifecycle by creating custom-tailored chef-solo recipes.

While Amazon provides a powerful deployment layer for PHP applications, it stops short once the PHP code has been checked out of git.  For Laravel or other composer apps, you’ll have to customize your deployment.  The most elegant and straightforward method is through custom deployment hooks.  Here’s how to build a before_migration.rb script to build a Laravel app …

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