E-Artspace labs

This article shows how to extract some ITSMO metadata form a subversione repository.

ITSMO is a vocabulary to annotate IT services. "Configuration Item" it is one of its main concept. An important  Configuration item property is its relation with a "configuration" stored in a CMDB . Subversion it is an easy way to manage such configuration .

The command  svn info, committed in a directory controlled by subversion produces an output like this:

Path: .
URL: https://subversion.assembla.com/svn/itsmo/trunk/v1
Repository Root: https://subversion.assembla.com/svn/itsmo
Repository UUID: aa9e2203-f931-4cdb-89b8-cce8243f9edb
Revision: 127
Node Kind: directory
Schedule: normal
Last Changed Author: e-artspace
Last Changed Rev: 127
Last Changed Date: 2011-09-04 10:01:38 +0000 (Sun, 04 Sep 2011)

From this output we can extract some meta-data that we can annotate with ITSMO ontology, mainly:

1. Configuration URI  ( itsmo:hasConfiguration)  from URL field
2. CMDB URI  ( itsmo:hasCMDB) from  Repository Root field
3. Baseline URI ( itsmo:hasBaseline ) that you can obtain from Revision field. A quick and dirty way to produce a valid URI is to concatenate the revision to the configuration URI like this:
   https://subversion.assembla.com/svn/itsmo/trunk/v1#127
   Unfortunately this UTI is not perfect dereferenziato (it does not dereference well). Another method is to compose the snapshot URI using the hints contained in  this this articole like https://subversion.assembla.com/svn/itsmo/trunk/!svn/bc/127/trunk/v1

Here is a sample php code fragment to extract and present subversion metadata:

<?php
//Place this code in the configuration directory
class SvnITSMOMetadata{
 protected function  parseInfo($s){
      return preg_match("/$s:s+(.*)/",$this->svninfo, $matches)?trim($matches[1]):"unknown";
 }
 
 public function __construct($subject) { 
  $this->subject=$subject;
  exec('svn info', $out);
  $this->svninfo=implode("n",$out);
  $this->CMDB=$this->parseInfo('Repository Root');
  $this->configuration=$this->parseInfo('URL');
  $this->revision=$this->parseInfo('Revision');
  $this->baselinePath=substr($this->configuration, strlen($this->CMDB));
  $this->baselineURI= $this->CMDB.'/!svn/bc/'.$this->revision.$this->baselinePath;
 }
 
 public function showTurtle(){
    echo "
     @prefix itsmo: <http://ontology.it/itsmo/v1#>
     <$metadata->subject> itsmo:hasConfiguration <$metadata->configuration>;
        rdfs:comment 'The based subversion configuration for $this->subject'.
        itsmo:hasCMDB <$metadata->CMDB>;
        itsmo:hasBaseline <$this->baselineURI>;
     <$this->baselineURI> rdfs:label 'Revision $this->revision';
        rdfs:comment '$this->svninfo'.
    ";
 }
}

$metadata= New SvnITSMOMetadata("http://example.com/MyConfigUri");
$metadata->showTurtle();