Carabiner 1.4: Asset Management Library

[eluser]topherdan1[/eluser]
I think I have Amazon S3/CDN integration with Caribinner working pretty well now. Here are the steps I took:

1. Add an S3 library to your application/libraries folder. I used the one available here: http://undesigned.org.za/2007/10/22/amazon-s3-php-class and then customized it so that it pulled the variables from my config file. The only thing I changed in the S3.php file (which is the one to add to application/libraries) was the __construct on line 57 so that it looked like this:

Code:

public function __construct($accessKey = null, $secretKey = null, $useSSL = true) {
      //Start Customizations
      $this->CI = get_instance();
    $accessKey = $this->CI->config->item('key_id');
    $secretKey = $this->CI->config->item('secret_key');
    //End Customizations
        if ($accessKey !== null && $secretKey !== null)
            self::setAuth($accessKey, $secretKey);
        self::$useSSL = $useSSL;
    }

2. Next, update the carabiner config file with the following variables

Code:

$config['key_id'] = 'XXXXXXXX'; //Your Amazon key_id
$config['secret_key'] = 'XXXXX'; //Your Amazon secret_key
$config['cdn_bucket'] = 'yourcdnbucket'; //The bucket that will act as your CDN
$config['use_cdn'] = TRUE; //Enabling the CDN functions in carabiner
$config['cdn_url'] = 'http://cdn.example.com/'; //The URL used to access your CDN

3. Finally, modify the carabiner library in two spots:
The _cache function should look like this:

Code:

private function _cache($filename, $file_data)
    {

        $filepath = $this->cache_path . $filename;
        $success = file_put_contents( $filepath, $file_data );

        if($success) :
            log_message('debug', 'Carabiner: Cache file '.$filename.' was written to '.$this->cache_path);
      
      if($this->CI->config->item('use_cdn') == TRUE)
      {
        //If it's a production environment, move the file to the Amazon S3 CDN bucket
        if($this->dev == FALSE)
        {
          $this->CI->load->library('S3');
          $this->CI->s3->putObjectFile($filepath, $this->CI->config->item('cdn_bucket'), $this->cache_dir.$filename, S3::ACL_PUBLIC_READ);
        }
      }

      
            return TRUE;
        else :
            log_message('error', 'Carabiner: There was an error writing cache file '.$filename.' to '.$this->cache_path);
            return FALSE;
        endif;
    }

The _tag function should look like this:

Code:

private function _tag($flag, $ref, $cache = FALSE, $media = 'screen')
    {

        switch($flag){
        
            case 'css':
                
                $dir = ( $this->isURL($ref) ) ? '' : ( ($cache) ? $this->cache_uri : $this->style_uri );
        
        if($this->CI->config->item('use_cdn') === TRUE && $this->dev == FALSE)
        {
          $dir = $this->CI->config->item('cdn_url').$this->cache_dir;
        }
                
                return '<link type="text/css" rel="stylesheet" href="'.$dir.$ref.'" media="'.$media.'" />'."\r\n";
            
            break;

            case 'js':
                
                $dir = ( $this->isURL($ref) ) ? '' : ( ($cache) ? $this->cache_uri : $this->script_uri );
                
        if($this->CI->config->item('use_cdn') === TRUE && $this->dev == FALSE)
        {
          $dir = $this->CI->config->item('cdn_url').$this->cache_dir;
        }
        
                return '[removed]CI->config->item('charset').'">[removed]'."\r\n";
            
            break;
        
        }
    
    }

That should be it. Now when you are in a production environment, anytime a new cache file is created it will automatically be loaded into Amazon S3, which can act as a CDN. Then, on the site, the files use the CDN domain instead of the normal domain. Let me know if you have suggestions on how to improve this.