Wanderlust

Tuesday, April 16. 2013
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At the last meetup of the Berlin PHP Usergroup, Christoph gave a talk about Vagrant.

Good enough of a reason to write down or re-cap some things I've learned with or about Vagrant over the last two years.

Base boxes

There are lots of base boxes available, but don't be tempted to rely on them (e.g. via config.vm.box_url).

  1. Vagrantbox.es doesn't actually mirror images and that is a huge pain.
  2. Available base boxes tend to be outdated. (Think kernel, packages, etc.) Running updates each time you provision is painful.
  3. Available base boxes use U.S. mirrors only/mostly/always — because we all live in the U.S. of A..
  4. Your VirtualBox guest additions may not match with your system and this may create random issues.

Your best bet is to create your own base box and establish a workflow e.g. using veewee or bento.

At EasyBib, we use bento and we created a definition which replaces the sources with Ubuntu's nifty mirror syntax (since we're pretty distributed at times, everyone appreciates this) and upgrades the base system. Either one of these tools introduce more Ruby into your organization and you may think "WTF — why do I need this?!", but the clear advantage is that no one has to write down a lot of steps how to recreate these boxes and anyone can do it.

In bento's case, the requirement is Ruby 1.9.1+ (getting this installed is IMO the hardest) and bundler. bundle install in your bento-clone gets you everything needed and then the three commands require build, validate and export a box which is ready to use. Ensure to put whatever you need into the definition — for example in the update.sh. Avoid too many manual steps before you export because the next person will have to know and repeat them. Bento serves as documentation as well.

I version our boxes with like easybib-something-10.04.4_vbox-4.1.8_0.1.box and upload them to an S3 bucket. The first number is the Ubuntu release and the second is the version of the VirtualBox guest additions. Simple. The third version is our internal iteration — typically a base box isn't perfect from the beginning while e.g. the Ubuntu and VirtualBox part are settled, there might be other improvements. With an extra version you avoid conflicts and extra work like vagrant box delete etc. and ensure the latest box is always used.

Also — in case the software stack is very different across your projects, it also helps to to create different boxes which come with different software pre-installed.

Standardize on versions

Vagrant and VirtualBox have frequent releases. I suggest to standardize on one so members of your team don't have random issues at hand and fires to fight.

Even for a small team of up to ten developers this makes a lot of sense. Because people tend to add a lot of randomness anyway — different hardware, operating systems and so on. Fight only the battles you want to fight, and deploy otherwise.

Vagrant also recently went from being a rubygem to providing installers. I haven't had the time to roll this out yet, but I expect this to help as well since at least as far as ruby is concerned all the dependencies are bundled.

This of course still implies that testing is required so you and your team don't walk into a stupid little regression and waste away the day trying to figure out what went wrong. And of course even if Vagrant is smoother, it still leaves you with VirtualBox and tools like bento and plenty of potential breakage.

Chef Versions

On a side-note — Chef 10 and 11 may also introduce a lot of breakage in recipes. It helps to roll your base box with a specific version as well. With bento the work-around was pretty straight forward: I replaced the chef-client.sh and installed Chef 10 (instead of 11 — or whatever the latest is).

VirtualBox and guest additions

In theory, it's alright to run with different guest additions in a box than the version of VirtualBox you have installed on the host. It should at least match the main release — for example: 4.1.8 guest additions and 4.1.12 VirtualBox should do fine. That's a big should though, because it also may cause random issues like crashes and hangs.

If you don't want or cannot rebuild the base box for some reason, you can also use vbguest which is a Vagrant plugin to update the guest additions when you start the virtual machine. Keep in mind that this adds a couple minutes to the bootstrapping.

Learn some Ruby

There are little things where it helps to know a little Ruby. And by Ruby, I don't mean Rails. A Vagrantfile itself is Ruby code — this implies that it is fully customizable.

An example of something we as a team couldn't agree on is the location of where projects (and essentially cookbooks) are located on your local disk. Every other team member has a different preference:

case ENV['USER']
when 'till'
  local_cookbook_dir = "~/Documents/workspaces/easybib-cookbooks"
when 'someonelse'
  local_cookbook_dir = "~/dev/till/easybib-cookbooks"
else
  local_cookbook_dir = "~/Sites/easybib/cookbooks"
end

if not File.directory?(File.expand_path(local_cookbook_dir))
  raise "You need to checkout your cookbooks into #{local_cookbook_dir}"
end

# ...

web_config.vm.provision :chef_solo do |chef|
  chef.cookbooks_path = local_cookbook_dir
  chef.add_recipe "ohai"
  # ...
end

It's as simple as that.

Another example — setting VirtualBox options for everyone but a certain user:

web_config.vm.boot_mode = :gui unless ENV['USER'] == 'mr_I_dont_run_X'

Bonus tip: Once you made changes, make sure to at least re-provision. Commit and push after!

Learn Chef or Puppet

I often see projects where developers end up writing a lot of shell script to bootstrap VMs, but learning Chef or Puppet is not really that hard.

I find it harder to validate exit codes (again and again and again) in bash than using a DSL (which is what Chef and Puppet essentially are). The code in your cookbooks (Chef) or manifests (Puppet) is certainly not faster than a shell script but a lot easier to read and more maintainable in the end.

Bash-scripting is not hard either, but in order to produce a set of scripts which can be ran again and again (not just to bootstrap a fresh VM but e.g. also to run updates on one that is running), defensive coding is paramount. And while that is certainly not impossible, it's often a waste of time when frameworks like Chef or Puppet have that covered.

But let's skip on the benefits of using identical tools to bootstrap Vagrant, staging and production because I find them more than obvious.

Learn some Linux

Every once in a while you will run into weird issues with the VMs. These may include one of your VMs losing connectivity (sudo restart networking to the rescue) or weird behavior like assets not refreshing (sendfile off; in nginx). Take it as an opportunity to learn some about the system that is run in production.

In the end all required configuration changes will go back into your provisioning and make sure to share your experience with at least the people on your team.

Backup everything

Whatever you find and use — make a copy of it and put it on Amazon S3 or the local network. With larger teams even a local Ubuntu mirror (or whatever you use) can come in handy.

This includes base boxes, packages, etc.. Nothing is more annoying than waking up and not being able to bootstrap your VMs because someone decided to remove something in order to force you to upgrade.

Don't dumb it down!

Typically, PHP applications are developed on a single host — Apache, PHP and MySQL on localhost. With Vagrant it becomes surprisingly easy to mimic production.

Not to say that I have to run 20 virtual machines to copy my cluster of application servers, but it's perfectly acceptable to set up an environment with four VMs where one is a loadbalancer, two are application servers and then a database server.

Networking and port forwards

Unless you regulary let others use your VMs, don't add port forwards — or at least install a firewall.

For networking, I suggest you either use static IPs (and keep track of them in a sheet) or DHCP. I prefer static IPs though since that makes configuration (e.g. of an application to connect to the database) easier.

It also doesn't hurt to assign names, so you know which VM you're dealing with when GUI is enabled:

    db_config.vm.customize [
      "modifyvm", :id,
      "--name", "DB",
    ]

Hardware

It doesn't hurt to have lots of CPU and RAM, but also configure the VMs accordingly. I run up to four virtual machines on a Macbook Air — usually configured with 256 to 512 MB. I imagine this would go smoother with VMWare Fusion, but since our team contains Mac and Linux as well, we haven't moved on this.

Here's an example how to give 512 MB RAM to a virtual machine:

    db_config.vm.customize [
      "modifyvm", :id,
      "--memory", "512"
    ]

Fin

That's all I can think of right now. Happy development!

Vagrant: ShellProvisioner vs. Chef

Wednesday, June 20. 2012
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In my last blog entry, I demo'd how to get started with Vagrant and the ShellProvisioner.

To further illustrate how amazingly simple it is to get started on some Ruby, I'll convert the shell script from my last blog post to a little recipe for chef. Same objective, we install a PEAR package — but it could be anything really.

Follow me.

Shell

This is the shell script from before:

#!/bin/sh

apt-get update

apt-get install -y php5 php5-cli php-pear
hash -r

pear upgrade-all
pear install -f HTTP_Request2

Ruby

Create a cookbooks directory and create structure for your first cookbook in it:

$ mkdir -p my-cookbooks/first/recipes/

Create a default.rb file with the following content:

# my-cookbooks/first/recipes/default.rb
execute "apt-get update"

packages = ["php5", "php5-cli", "php-pear"]

packages.each|p| do
  package p
end

execute "pear upgrade-all"
execute "pear install -f HTTP_Request2"

The recipe is later referred to as first or first::default (name of the recipe directory, name of the .rb).

It's so simple it hurts. ;)

Step by step

  1. I run apt-get update using Chef's execute resource.
  2. I create an array of the packages (Arrays are ordered in Ruby, hashes are not (up until Ruby 1.9.x). Order is important here.)
  3. I run pear upgrade-all using the execute resource.
  4. I run pear install using the execute resource.

Vagrantfile

The Vagrantfile looks slightly different when you provision with chef-solo:

Vagrant::Config.run do |config|

  config.vm.define :web do |web_config|
    web_config.vm.box       = "lucid64"
    web_config.vm.host_name = "web"

    web_config.vm.provision :chef_solo do |chef|
      chef.cookbooks_path = "PATH-TO-YOUR-COOKBOOKS"
      chef.add_recipe "first"
      chef.log_level = :debug
    end
  end

end

The important bit: the path to the location of your cookbooks — could be an /absolute/path or ./../relative/path.

Because a Vagrantfile is essentially Ruby code, anything goes here.

Further reading

Getting started with Chef and Ruby can be intimidating or even frustrating at times. Google "chef cookbooks" and you know what I mean.

These links are what you need:

Fin

Save, and enjoy — vagrant up.

Vagrant sans Ruby

Tuesday, June 5. 2012
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Development, testing, staging and production — this is how most people devide up different environments for application development.

Maintenance and setup of these environments is often not a trivial goal to achieve. Having worked with a couple different code bases and setups over the last decade, I often noticed things like environment specific hacks (if ($env == 'testing') { ... }) in application code and service configurations and a lot of manual labour all around. It's still very common that code deployed to staging does not work — but it worked for you right?

And it's also too common that members of a team do not know how something works because whoever set it up is currently out sick or on vacation.

My opinion is that the best setup currently available is something like: chef(-solo) on the server and Vagrant on the desktop. Something like because aside from chef, there is also puppet, cfengine and a couple others. Leaving specific projects aside, it really just boils down to automation (within reason).

Automation in my opinion is not just the easiest but the only viable way to setup development, testing, staging and production environments. Without some automation in place it's required that all team members know how all of it works when maybe that is not yet important and the end goal is that all environments actually resemble each other.

Enter Vagrant

Vagrant is a very nifty toolkit to bootstrap Virtualbox images. Bootstrapping means installing your application stack into one or multiple virtual machines in order to resemble production a lot better.

So a lot of times when I rave about how useful Vagrant and chef are, I get the crazy eye from PHP developers:

You want me to learn Ruby to setup my local development environment?

My response:

  1. Do not fear the Ruby.
  2. You don't have to. (Well, not a whole lot!)

Real talk

First off, of course you need Virtualbox — get a download from their website or use your package manager.

Then, it's not possible to avoid Ruby a 100% — after all Vagrant is written in Ruby.

When you're on a Linux or a Mac, this is usually enough (you may need sudo unless you RVM):

$ sudo gem install vagrant

For a sudo-less install, use RVM:

$ sudo gem install rvm
...
$ rvm install
...
$ rvm use 1.8.7
...

When set up, this is what you do:

$ gem install vagrant
...

RVM allows me to run multiple versions of ruby side by side and also leverage local gem installs — per Ruby version. Think of it as a nifty way to run multiple PHP versions and have a PEAR install per version — similar projects exist for PHP today:

To learn more about RVM, visit their website.

Once vagrant is installed, we can continue!

ShellProvisioner for fun and profit

So, in case you are more comfortable writing some shell script for the time being — Vagrant got you covered!

First off, create a new Vagrantfile for your project:

$ mkdir -p Documents/workspaces/blog-example/
$ cd Documents/workspaces/blog-example
$ vagrant init lucid64
A `Vagrantfile` has been placed in this directory. You are now
ready to `vagrant up` your first virtual environment! Please read
the comments in the Vagrantfile as well as documentation on
`vagrantup.com` for more information on using Vagrant.

lucid64 (Ubuntu Lucid 10.04, 64bit) is the name of one of my local box files for Vagrant. In case you haven't got a box yet, head over to vagrantbox.es. There are a couple images you (aka box files) you can download. To get the lucid64 box, use the following command:

$ vagrant box add lucid64 http://files.vagrantup.com/lucid64.box

Once you made it past vagrant init, you should have a Vagrantfile with a lot of stuff in there.

While it's not important for my tutorial, I recommend you review it some (other time). The created Vagrantfile contains examples for all the provisioners (puppet, chef and shell) and a couple other configuration options, etc..

Let's skip over this and get to the ShellProvisioner.

This is all you need

First off, let's create a shell script setup.sh in the same directory and put something like this in it:

#!/bin/sh

apt-get update

apt-get install -y php5 php5-cli php-pear
hash -r

pear upgrade-all
pear install -f HTTP_Request2

What does it do?

  1. Update local package sources.
  2. Install php5, cli interpreter and PEAR installer
  3. reload environment
  4. upgrade all installed PEAR packages
  5. install PEAR HTTP_Request2

When you're done editing, make sure to chmod +x it.

Simple as that.

Putting your shell script to use

Replace your Vagrantfile with the following:

Vagrant::Config.run do |config|

  config.vm.box = "lucid64"
  config.vm.provision :shell, :path => "./setup.sh"

end

Then, run vagrant up and watch it provision. :)

Enter your virtual machine with vagrant ssh and verify HTTP_Request2 is installed:

$ vagrant ssh                                                                                                                                                               [14:16:08]
Linux lucid64 2.6.32-33-server #70-Ubuntu SMP Thu Jul 7 22:28:30 UTC 2011 x86_64 GNU/Linux
Ubuntu 10.04.3 LTS

Welcome to the Ubuntu Server!
 * Documentation:  http://www.ubuntu.com/server/doc
Last login: Thu Jul 21 14:08:15 2011 from 10.0.2.2
vagrant@lucid64:~$ pear list -c pear
Installed packages, channel pear.php.net:
=========================================
Package          Version State
Archive_Tar      1.3.10  stable
Console_Getopt   1.3.1   stable
HTTP_Request2    2.1.1   stable
Net_URL2         2.0.0   stable
PEAR             1.9.4   stable
Structures_Graph 1.0.4   stable
XML_Util         1.2.1   stable

Yay — your first steps into automation!

Fin

That's all for today — Vagrant with almost no Ruby. I hope this gets many more started!

Deploying PHP applications: PEAR and composer resources for chef

Thursday, February 23. 2012
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This is something experimental I have been working on for our chef deployments. So the objective was/is to find a sane way to install PEAR packages and install dependencies with composer.

execute in chef recipes

In chef recipes, almost everything is a resource. In case you're just getting started with Chef, a list of current resources is available on the Opscode Wiki. It's a link I put in my browser bar since I frequently work on chef recipes.

Some examples for resources are:

  • package (to install software)
  • cron (setup a crontab)
  • directory (create directories)
  • template (install customized configuration files)
  • user and group (to create users and groups)
  • mdadm (to setup a RAID)

The above list are examples — so there is more. But if there isn't a designated resource, you can always use an execute block.

An example for an execute block is the following:

execute "discover a pear channel" do
  command "pear channel-discover easybib.github.com/pear"
end

This works pretty well, but it is also not very robust.

Fail hard

By default whenever a command fails, chef fails hard.

To illustrate what I'm talking about, let's test and execute the command from our execute block multiple times on the shell to see its exit status ($?):

till:~/ $ pear channel-discover easybib.github.com/pear
Adding Channel "easybib.github.com/pear" succeeded
Discovery of channel "easybib.github.com/pear" succeeded
till:~/ $ echo $?
0
till:~/ $ pear channel-discover easybib.github.com/pear
Channel "easybib.github.com/pear" is already initialized
till:~/ $ echo $?
1

So whenever a command returns not 0, chef will bail.

One solution is to brute-force your way through these things with ignore_failure true in your execute block. But that's usually not a great idea either because it hides other issues from you (and me) when we need to debug this later on.

For example, if this PEAR channel is unavailable during your next chef-run, it would be much, much harder to find the root cause as of why the install commands failed.

Another solution is using the not_if or only_if options with execute:

execute "discover a pear channel" do
  command "pear channel-discover easybib.github.com/pear"
  not_if do
    `pear channel-info easybib.github.com/pear`
  end
end

If the command wrapped in not_if succeeds (success is exit status), we would skip the execute block.

Optimize?

Since I discovered not_if and only_if, it allows me write recipes which work in most cases. More robust code, which allows me to re-execute recipes on already running instances. So for example when I update a recipe or configuration file which is distributed through a recipe I can re-run the entire recipe and it will not fail but instead complete successfully.

One problem remains with this approach I end up doing the same checks again and again.


Continue reading "Deploying PHP applications: PEAR and composer resources for chef"

Cooking PHPUnit (and a chef-solo example on top)

Sunday, December 4. 2011
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I'm sure most of you noticed that with the recent upgrade of PHPUnit to version 3.6, a lot of breakage was introduced in various projects.

And for example Zend Framework 1.x won't update to the latest version either. When I ranted on twitter someone send me Christer Edvartsen's blog post on how to setup multiple versions of PHPUnit. It's really neat since it walks you through the setup step by step and you learn about things such as --installroot on the way. --installroot in particular is something I never ever saw before and I've been using PEAR for more than a few years now. So kudos to Christer for introducing myself to it.

The only thing to add from my side would be, Why are you guys not aggregated on planet-php?.

Cooking with Chef

Another reason why I decided to write this blog entry was that I created a chef-recipe based on Christer's blog entry.

If you follow my blog for a while, you might have noticed that I'm a huge fan of automation. I just moved one of our development servers the other day and had one of these moments where something just paid off. Taking for granted that I can spin up fully operational EC2 instances in minutes, I also had our development stack installed and configured in an instant.

My recipe basically follows Christer's instructions and because I distribute phpunit's command along with it, editing of the file is no longer required: when the chef run completes, phpunit34 is installed and ready to be used.

Get started

I'm doing the following commands as root — my setup is in /root/chef-setup.

Install chef(-solo) and clone my cookbooks

shell# gem install --no-ri --no-rdoc chef
... 
shell# git clone git://github.com/till/easybib-cookbooks.git
...

Chef configuration

Then setup a node.json file which chef-solo will need to run:

{
  "run_list": [
    "recipe[phpunit]"
  ]
}

Then create a solo.rb:

file_cache_path "/var/chef-solo"
cookbook_path ["/root/chef-setup/easybib-cookbooks"]

Chef run

Finally we start chef-solo with following command:

shell# chef-solo -c /root/chef-setup/solo.rb -j /root/chef-setup/node.json -l debug
...

The command runs chef-solo (which is part of the gem we installed) and reads the basic configuration from the solo.rb-file. This file contains the location of the cookbooks (remember git clone ...) and a path to cache files. You don't need to create anything, it should be all taken care of.

The node.json-part allows us to set node-specific values. The prime example is the run-list, but it allows you to set attributes as well. Attributes contain values for variables used in recipes, but are not used in this example.

Last but not least: -l debug — a lot of useful output, but we usually run with -l warn. And if this is interesting enough for you, I suggest the other blog entries I wrote on this topic.

Did it work?

Depending on the location of your pear setup — usually /usr/bin/pear or /usr/local/bin/pear — the phpunit34 script is created in the same path:

shell# which phpunit34
/usr/local/bin/phpunit34

Yay!

Fin

This feels like hitting two birds with one stone. Though just by figure of speech! I object to violence against birds.

It might be overkill to setup chef to just install phpunit 3.4 by itself, but I think this serves as a stellar example of how you can leverage the power of chef to get more done. Writing a couple more recipes to install and configure the rest of your stack shouldn't be too hard.

If you'd like to see anything in particular: I'll take requests via email, Twitter or in the comments.