122 lines
4.6 KiB
Markdown
122 lines
4.6 KiB
Markdown
---
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title: "AWS OpsWorks: Lessons Learned"
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date: 2013-10-04T00:00:00+00:00
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draft: false
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canonical_url: https://www.viget.com/articles/aws-opsworks-lessons-learned/
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references:
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- title: "Introduction to AWS OpsWorks - Artsy Engineering"
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url: https://artsy.github.io/blog/2013/08/27/introduction-to-aws-opsworks/
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date: 2024-11-21T15:35:22Z
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file: artsy-github-io-sroaub.txt
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---
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We've been using Amazon's [AWS
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OpsWorks](http://aws.amazon.com/opsworks/) to manage our infrastructure
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on a recent client project. The website describes OpsWorks as
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> a DevOps solution for managing applications of any scale or complexity
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> on the AWS cloud.
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You can think of it as a middle ground between something like Heroku and
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a manually configured server environment. You can also think of it as
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[Chef](http://www.opscode.com/chef/)-as-a-service. Before reading on,
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I'd recommend reading this [Introduction to AWS
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OpsWorks](http://artsy.github.io/blog/2013/08/27/introduction-to-aws-opsworks/),
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a post I wish had existed when I was first diving into this stuff. With
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that out of the way, here are a few lessons I had to learn the hard way
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so hopefully you won't have to.
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### You'll need to learn Chef
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The basis of OpsWorks is [Chef](http://www.opscode.com/chef/), and if
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you want to do anything interesting with your instances, you're going to
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have to dive in, fork the [OpsWorks
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cookbooks](https://github.com/aws/opsworks-cookbooks), and start adding
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your own recipes. Suppose, like we did, you want to add
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[PDFtk](http://www.pdflabs.com/tools/pdftk-the-pdf-toolkit/) to your
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servers to merge some documents:
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1. Check the [OpsCode
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Community](http://community.opscode.com/cookbooks) site for a
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recipe.
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2. [A recipe exists.](http://community.opscode.com/cookbooks/pdftk) You
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lucky dog.
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3. Add the recipe to your fork, push it up, and run it.
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4. It fails. Turns out they renamed the `gcj` package to `gcj-jdk`.
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Fix.
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5. It fails again. The recipe is referencing an old version of PDFtk.
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Fix.
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6. Great success.
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A little bit tedious compared with `wget/tar/make`, for sure, but once
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you get it configured properly, you can spin up new servers at will and
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be confident that they include all the necessary software.
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### Deploy hooks: learn them, love them
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Chef offers a number of [deploy
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callbacks](http://docs.opscode.com/resource_deploy.html#callbacks) you
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can use as a stand-in for Capistrano's `before`/`after` hooks. To use
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them, create a directory in your app called `deploy` and add files named
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for the appropriate callbacks (e.g. `deploy/before_migrate.rb`). For
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example, here's how we precompile assets before migration:
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```ruby
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rails_env = new_resource.environment["RAILS_ENV"]
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Chef::Log.info("Precompiling assets for RAILS_ENV=#{rails_env}...")
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execute "rake assets:precompile" do
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cwd release_path
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command "bundle exec rake assets:precompile"
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environment "RAILS_ENV" => rails_env
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end
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```
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### Layers: roles, but not *dedicated* roles
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AWS documentation describes
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[layers](http://docs.aws.amazon.com/opsworks/latest/userguide/workinglayers.html)
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as
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> how to set up and configure a set of instances and related resources
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> such as volumes and Elastic IP addresses.
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The default layer types ("PHP App Server", "MySQL") imply that layers
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distinguish separate components of your infrastructure. While that's
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partially true, it's better to think about layers as the *roles* your
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EC2 instances fill. For example, you might have two instances in your
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"Rails App Server" role, a single, separate instance for your "Resque"
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role, and one of the two app servers in the "Cron" role, responsible for
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sending nightly emails.
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### Altering the Rails environment
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If you need to manually execute a custom recipe against your existing
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instances, the Rails environment is going to be set to "production" no
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matter what you've defined in the application configuration. In order to
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change this value, add the following to the "Custom Chef JSON" field:
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```json
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{
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"deploy": {
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"app_name": {
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"rails_env": "staging"
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}
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}
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}
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```
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(Substituting in your own application and environment names.)
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------------------------------------------------------------------------
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We've found OpsWorks to be a solid choice for repeatable, maintainable
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server infrastructure that still offers the root access we all crave.
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Certainly, it's slower out of the gate than spinning up a new Heroku app
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or logging into a VPS and `apt-get`ting it up, but the investment up
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front leads to a more sustainable system over time. If this sounds at
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all interesting to you, seriously go check out that [introduction
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post](http://artsy.github.io/blog/2013/08/27/introduction-to-aws-opsworks/).
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It's the post this post wishes it was.
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