Till's blog | Entries tagged as pear

Entries tagged as pear

Vagrant: ShellProvisioner vs. Chef

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

I run apt-get update using Chef's execute resource.
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.)
I run pear upgrade-all using the execute resource.
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.

Fin

Save, and enjoy — vagrant up.

Vagrant sans Ruby

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:

Do not fear the Ruby.
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?

Update local package sources.
Install php5, cli interpreter and PEAR installer
reload environment
upgrade all installed PEAR packages
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
[email protected]:~$ 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

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.

Twitter bootstrap + Zend_Form = ♥

I dig Twitter's bootstrap library because as a developer, it helps me produce good looking forms without a lot of effort. Especially when administration interfaces are concerned, ~~you~~ I can only go so far — my first constraint is not being a great designer (to confirm, check out this blog) and two: I don't like working with ugly interfaces.

To cut to the chase...

Easybib_Form_Decorator

It's a decorator library for Zend_Form. Among the Twitter Bootstrap style, it also supports simple <div> and <table> styles — all courtesy of the awesome Michael Scholl. The code is MIT licensed: it should suit your budget just fine. ;-)

Installation

(Side-note: We got a PEAR channel.)

$ pear channel-discover easybib.github.com/pear
$ pear install easybib/Easybib_Form_Decorator-alpha

Usage

See the docs folder on github.

Fin

Questions, comments and feedback are always appreciated — pull requests are most welcome.

A roundhouse kick, or the state of PHP

Last week the usual round of PEAR-bashing on Twitter took place, then this morning Marco Tabini asked if PHP (core) was running out of scratches to itch. He also suggests he got this idea from Cal Evan's blog post about Drupal forking PHP.

http://blog.tabini.ca/2011/04/is-php-running-out-of-itches-to-scratch/
http://blog.calevans.com/2011/04/07/four-reasons-why-drupal-should-fork-php/

[Not submitting to your linkbait.]

Pecl and PHP

So first off — moving libraries from the core to an external repository was done for various reasons. One of them is to not have to maintain more and more in the core — keep it small and lean. Though small is pretty relative in this respect.

Of course doing so, means that people who do not have root on a server cannot install the module in most cases. But I'm inclined to suggest that when a pecl extension is (really) required, there should be nothing holding you back.

And if there is no way, thanks to PHP's extentability there's almost always a PHP-equivalent to any c-extension available.

Drupal and PHP

I know a couple Drupal people myself and most of them consider themselves to be Drupal developers before PHP. Why is that? It's because Drupal found a great way to abstract whatever people annoys about PHP from its developers, thus enabling them to build websites.

Is this a good or bad thing?

Of course it's a good thing because it makes people productive.

It's also a bad thing, because it seems that some (Drupal) people are rather disconnected from upstream [PHP].

Enabling people

Whatever people think about Drupal or any other framework, keep in mind that apparently it's PHP (and not Ruby, Python or pure C) which is more than a good enough enabler because PHP allows people to build a sophisticated content-management-framework like Drupal on top of it.

Drupal is of course no exception here. Despite e.g. the standstill in Ruby-land, in PHP other tools developer over the years who are a defacto standard: take a look at Wordpress or phpBB.

If you'd like to take it down to the framework-level there are projects like Symfony, CodeIgniter, Zend Framework, ezComponents/Zeta and also PEAR.

Fork vs. wat?

I think that forking PHP is a joke and I believe that Cal doesn't know the difference between a fork and a custom package (or a distribution).

A fork usually adds or removes features from the actual code base, but reading Cal's blog post he suggests a custom package. [Woo! Technical details! They get lost along the way!]

The thing is that a lot of people do this already. The people maintain a PHP package for a certain Linux or Unix distribution — Debian/Ubuntu, Gentoo or FreeBSD — there are doing it already. Using these as an example, whatever OS is used, it already runs a customized version PHP; some distributions customize more than others.

No one objects to the Drupal community suggesting ./configure flags or maintaining packages for the various flavours of Linux and Unix, or even Windows.

I would even go as far and say that in order to optimize the stack completely, it wouldn't hurt Drupal if its community recommended flags and extensions for people who run Drupal sites.

I doubt though that anyone will maintain packages for a couple distributions in their spare time and that the majority will not benefit from this effort because they don't run Drupal on their own server. But generally this optimization is enterprisey enough and indeed what I call a business opportunity.

Moving Drupal to ...

So what's "..."? Moving it to Python or Ruby, or maybe Scala? Good luck with that.

While the majority of Drupal developers don't consider themselves to be PHP developers, they still live and benefit off the PHP ecosystem. Think libraries used in modules or used for other areas like testing. Good luck porting those.

Then add PHP's vast adoption among webhosts.

Last but not least

Which brings me to the in my opinion biggest selling point: Doing PHP has another slight advantage over Ruby, Python and the other languages — it's installed on over 90% of the shared webhosts out there.

I invite everyone to google php hosting. It's trivial to find a host for as low as a Dollar per month — you just can't beat that.

Dear Cal, if you call this a business opportunity, I wonder why there's no Dollar Ruby hosting yet. Or Java hosting for a Dollar. But maybe someone is just not seeing this great business opportunity? [Note, Sarcasm.]

PEAR and PHP

What really bothers me about flaming PEAR is that the most vocal people in these flamewars never contributed any code. Open source is different from the Monday morning meetings some people are used to and where they talk people against the wall.

In open source land actual code contributions take the lead.

And while a lot of people complain about PEAR in general, here's something else:

thriving download stats of packages
PEAR package usage in other projects
adoption of the PEAR coding standards and conventions
PEAR channels thriving
overall installer adoption

Despite being called a mess, PEAR is an enabler for many.

Point taken

PEAR being so many things is confusing!

PEAR packages are not as easy to use as some code you copy-pasted off the Zend devzone or phpclasses. While I agree, that we should try to make it just as easy, it's just not one PEAR's goals right now.

Scratching my own itch

Scratching your own itch, is what code contributions to PEAR are currently all about. Maybe always have been.

Active package maintainers most often contribute to packages they use themselves and they contribute to PEAR's environment to move development forward in areas where its beneficial to them. Call that selfish, but the reality is that most of us contributors actually work in this web industry and we know what we want and therefor we do it.

At the same time PEAR has coding standards and convention which are in place to ensure code is written so its to the benefit of most people.

Maintainership burden

The offiside to this situation is of course that components none of the maintainers have a use for get neglected — but calling this a PEAR-only problem really one-side.

Not even company-driven frameworks like the Zend Framework are prone to this; Zend_GData is/was rather unmaintained for a long time. Or frameworks where the proposal process and architecture are valued above all; I could point how broken ezcFeed is for me. Or general issues I see in projects where decisions are primarily driven by a single person — catch my drift?

This is not meant a pissing contest between frameworks, but I just can't hear it anymore.

Developer-friendly

Is PHP generally developer-friendly?

At the expense of watering the term developer, I'd say yes.

It is extremely easy to get started — embed the following into a .php file:

<?php
echo "Hello World";
?>

There's your PHP. It doesn't require a custom webserver process, root server or anything else. It really doesn't get any easier.

Are PHP frameworks easier than frameworks in [your other favorite language]?

Probably not! Or, hell no!

But that's the barrier of entry to any if not all frameworks on the planet. Some frameworks allow you to write your own blog in 10 steps, but you will soon discover that writing your own blog is not a great indicator for a quality framework.

Indiciators are:

maintained code
coding standards
tests

And if I'm allowed a snarky remark — these are areas Drupal is literally just getting around to.

PHP vs PHP

Destruction breeds creation — but I get the impression that all these fights inside the PHP community don't really make it foster more.

Fighting and trolling may be an art for some and I agree they are entertaining at times, but when it becomes the only way people ~~communicate~~ contribute then let me be clear: it doesn't help.

The PHP community seems to be unaware how thriving PHP is and also its ecosystem. People often mistake stabilization for decline. There's nothing wrong if we don't crank out five new major versions every year.

People in the real world are conservative anyway and adoption is slow. [Not a PHP-only problem either, just ask the Ruby folks.]
People in the real world don't mind a more stable PHP environment, at the expense of buzzwords and all that crap.

Fin

In hindsight everyone always knew.

I feel like the more vocal people sharing their opinion, are pretty disconnected from the reality. That is dispite them running a magazine or a podcast about the community.

When people resort to flaming others in order to make themselves look smarter or their own project better, then that's just poor judgement on their part. Projects often die off as fast as they came about.