Linux recursive directory listings

It’s sometimes really useful to recursively generate a list of directories, excluding the files.

I use this in build scripts to create lists of directories that will need to be generated on the remote server – this is useful for things like upload directories for user generated content that wouldn’t necessarily be under version control.

 
find . -type d

To exclude a directory within this path you can use:

 
find . -type d -not -path "./directory_to_ignore/*"

Modify an existing database column in a Laravel migration

I’ve been messing around with Laravel – the ‘Clean & Classy PHP Framework’… I’m not totally sold yet, but there is a lot to like, so I am persevering.

One useful feature that Laravel includes is migrations – in essence the ability to place your database schema under version control along with your code.

Laravel handles migrations though it’s CLI ‘Artisan

Rather inexplicably (to me at least*) the migrations tool – Schema Builder does include the ability to modify columns once they have been created, however you can use use raw SQL as a workaround.

*Schemas evolve. I find myself often adding columns, tweaking existing columns regularly and dropping columns rather rarely…

Let’s build some migrations…

First things first – create the migrations table. This is used to keep track of migration within your application.

1. Open a terminal in the root of your application.

2. Create the migrations table:

 
php artisan migrate:install

3. Create an empty migrations script

 
php artisan migrate:make create_users

create_users is simply a descriptive name for your migration – you can call it anything you want…

This will create a skeleton file in /path_to_laravel/application/migrations that includes the timestamp in it’s name e.g.

2013_05_23_201939_create_users.php

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
 
class Create_Users {
 
	/**
	 * Make changes to the database.
	 *
	 * @return void
	 */
	public function up()
	{
		//
	}
 
	/**
	 * Revert the changes to the database.
	 *
	 * @return void
	 */
	public function down()
	{
		//
	}
 
}

This isn’t much use – we need to:

4. Write our migration – edit the file that we just created. Create the table and insert some test data.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
 
class Create_Users {
 
	/**
	 * Make changes to the database.
	 *
	 * @return void
	 */
	public function up()
	{
		Schema::create('users',function($table){
			$table->increments('id');
			$table->string('username', 20); 
			$table->string('email', 255); 
			$table->string('password', 255); 
			$table->boolean('active');
			$table->timestamps(); 
		});
 
		DB::table('users')->insert(array(
					'username' => 'admin',
					'email' => 'test@test.com',
					'password' => Hash::make('123456'),
					'active' => 1
 
		));
	}
 
	/**
	 * Revert the changes to the database.
	 *
	 * @return void
	 */
	public function down()
	{
		//
	}

5. Run the migration:

 
php artisan migrate

6. Ooops – forgotten to set a default on one of the fields.

Unfortunately you can’t change this via the Schema Builder, but we can still use another migration:

 
php artisan migrate:make update_users

This will create a file called something like 2013_05_23_202930_update_users.php

7. We need to write our migration. This needs to be actual SQL which we call with DBquery e.g.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
 
class Modify_Users {
 
	/**
	 * Make changes to the database.
	 *
	 * @return void
	 */
	public function up()
	{
		DB::query("ALTER TABLE `ltest`.`users` CHANGE COLUMN `active` `active` tinyint(1) NOT NULL DEFAULT '1';");
 
		DB::table('users')->insert(array(
				'username' => 'test2',
				'email' => 'test2@test.com',
				'password' => Hash::make('123456'),
 
 
		));
	}
 
	/**
	 * Revert the changes to the database.
	 *
	 * @return void
	 */
	public function down()
	{
		//
	}
 
}

I’ll insert another user and see if the default for the ‘active’ column is set correctly.

8. Run the migrations again.

 
php artisan migrate

Done!

Installing Homebrew & Fabric on OSX

I recently started using Fabric to simplify my deployment process.

Fabric is a Python (2.5 or higher) library and command-line tool for streamlining the use of SSH for application deployment or systems administration tasks.

I quite like Fabric – I’m not 100% sold, but it’s easy to get started with and it won’t be long until you can write complex scripts.

Being able to deploy a complex app with a single command is great. I do not miss long checklists and having to run through step after step in a hurry.

fab deploy

Pretty easy isn’t it?

Why Fabric? To be honest – why not. I know a little bit of Python, so why not learn a bit more? I like the glueyness, the fact that it (mostly) lets you get on with things and doesn’t force you to work in a particular way.

I had a devil of a time getting it up and running though on my Mac running 10.6.8 (Snow Leopard).

Getting started…

Homebrew http://mxcl.github.io/homebrew/
is a package manager for OSX and alternative to MacPorts. Install Fabric and Python via Homebrew to (hopefully) make your life a bit easier…

Install Homebrew

Open a terminal. Run the commands as your user, not sudo

ruby -e "$(curl -fsSL https://raw.github.com/mxcl/homebrew/go)"

Install Homebrew and then check the install.

brew doctor

Running brew doctor will identify any problems with your install. Any problems are displayed. Work through any issues it flags up one by one. In my case I ended up having to remove MacPorts and had to reinstall Xcode.

Remove MacPorts

MacPorts is another package manager, but apparently it often doesn’t play with Homebrew.

Follow the instructions http://guide.macports.org/chunked/installing.macports.uninstalling.html

sudo port -fp uninstall installed
sudo rm -rf \
    /opt/local \
    /Applications/DarwinPorts \
    /Applications/MacPorts \
    /Library/LaunchDaemons/org.macports.* \
    /Library/Receipts/DarwinPorts*.pkg \
    /Library/Receipts/MacPorts*.pkg \
    /Library/StartupItems/DarwinPortsStartup \
    /Library/Tcl/darwinports1.0 \
    /Library/Tcl/macports1.0 \
    ~/.macports

Remove Xcode

Xcode is Apple’s Integrated Development Environment (IDE) containing tools for developing software for OS X and iOS.

Based on issues listed by brew doctor I removed Xcode and the re-installed it.

sudo /Developer/Library/uninstall-devtools --mode=all

Make sure you have your Apple ID to hand if you don’t have the .dmg and need to download it from Apple.

Install Git

Next I installed Git using Homebrew if you do not already have it (I use Mercurial day to day, so I didn’t)

brew install git
brew upgrade git

Install python

brew install python

Update your paths to use the version of Python that you’ve just installed.

sudo nano /etc/paths
nano ~/.bashrc

Install Fabric

pip install fabric

Edit: To install Fabric you need to use the pip package manager which was installed as part of Python.

Phew! Everything should be working now… time to write a fabfile.py