Dynamic Rack Generation from ServiceNow CMDB Rack Sys_ID

RackImage.php

<?php
include('../common.inc.php'); // Contains defintions for INSTANCE, USER, PASS

//////////////////////////////////
// GET THE RACK FROM sys_id in URL
$q='sys_id='.$_GET[sys_id];
$query=urlencode($q);

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://'.INSTANCE.'.service-now.com/cmdb_ci_rack_list.do?XML&useUnloadFormat=true&sysparm_query='.$query);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
curl_setopt($ch, CURLOPT_USERPWD, USER.':'.PASS); // locate in common.inc.php
$data = curl_exec($ch);
curl_close($ch);

$xmlIterator = new SimpleXMLIterator($data);
for( $xmlIterator->rewind(); $xmlIterator->valid(); $xmlIterator->next() ) {
    foreach($xmlIterator->getChildren() as $name => $data) {
        $RACK[(string)$name]=(string)$data;
    } // end foreach
} // end for


//////////////////////////////
// GET ALL THE CIS IN THE RACK
$q='u_in_rack.sys_id='.$RACK[sys_id];
$query=urlencode($q);

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://'.INSTANCE.'.service-now.com/cmdb_ci_hardware_list.do?XML&useUnloadFormat=true&sysparm_query='.$query);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
curl_setopt($ch, CURLOPT_USERPWD, USER.':'.PASS);
$data = curl_exec($ch);
curl_close($ch);

$xmlIterator = new SimpleXMLIterator($data);
for( $xmlIterator->rewind(); $xmlIterator->valid(); $xmlIterator->next() ) { $K++;
    foreach($xmlIterator->getChildren() as $name => $data) {
        if ($name=="u_rack_position")   $CIS[$K][$name]=(string)$data;
        if ($name=="sys_id")            $CIS[$K][$name]=(string)$data;
        if ($name=="name")              $CIS[$K][$name]=(string)$data;
        if ($name=="u_rack_units")      $CIS[$K][$name]=(string)$data;
    } // end for each
} // end for
unset($K);

/////////////////////////////////////
// SORT THE CI ARRAY BY RACK POSITION
function aasort (&$array, $key) {
    $sorter=array();
    $ret=array();
    reset($array);
    foreach ($array as $ii => $va) {
        $sorter[$ii]=$va[$key];
    }
    asort($sorter);
    foreach ($sorter as $ii => $va) {
        $ret[$ii]=$array[$ii];
    }
    $array=$ret;
}
aasort($CIS,"u_rack_position");

///////////////////////////////
// BUILD THE RACK DISPLAY ARRAY
# Populate with device label, and how many rack units of space it takes up
# Two special cases... 'rackname' gets applied to the top nameplate area
# 'blankXX' append random strings or numbers to avoid a name collision in php arrays
$rack['rackname']=$RACK[name];
for($i=$RACK[rack_units]; $i>=1; $i--){
    foreach($CIS as $v) {
        if($i==$v[u_rack_position]+$v[u_rack_units]-1) {
            $F = array( 'name'=>$v[name], 'units'=>$v[u_rack_units] );
            $i=$i-$v[u_rack_units]+1;
        }
    }// end foreach
    if($F) {
        $rack[$F[name]]=$F[units];
    } else {
        $rack['blank'.$i]=1;
    } // end if
    unset($F);
} // end for


//////////////////////////////////////////////////////////////////////////////////
// DRAW THE RACK
// http://www.jaredwatkins.com/2011/10/dynamic-rack-face-diagrams-with-php-and-gd/
// DOWNLOAD :: http://www.jaredwatkins.com/uploads/DynamicRackFaces1.zip
// All drawRack() code below this point courtesy of Jared Watkins
drawRack($rack, 'BlankRack'.$RACK[rack_units].'u.png');

function drawRack($r, $racktemplate) {
    $template = imagecreatefrompng($racktemplate);
    # Initial offset from the top left corner to begin placing 'servers'
    $dstX = 27;
    $dstY = 22;
    foreach ($r as $name => $u) {
        # This defines the nameplate at the top of the rack
        if ($name == 'rackname') {
            $nameplate = imagecreate(150,20);
            $background = imagecolorallocate( $nameplate, 255, 255, 255 );
            $text_colour = imagecolorallocate( $nameplate, 0, 0, 0 );
            imageCenterString($nameplate, 5, $u, $text_colour);
            imagecopy ($template, $nameplate, 52, 1, 0, 0, 150, 20);
            continue;
        } // end if
        $deviceimg = imagecreate (200, (20*$u));
        drawRackDevice(&$deviceimg,$name);
        imagecopy($template, $deviceimg, $dstX, $dstY, 0, 0, 200, (20*$u));
        $dstY += (20*$u);
        imagedestroy($deviceimg);
    } // end foreach

    # You could also save it to a file on disk
    header( "Content-type: image/png" );
    imagepng( $template );
    imagedestroy($template);
}

function drawRackDevice ($img, $text) {

    // sys_class_name color picked from ServiceNow
    // extended by AJ Simpkin 2013.12.19 hohoho!
    if($sys_class_name=='cmdb_ci_linux_server') { // blue
        $background = imagecolorallocate( $img, 100, 150, 200 );
    } elseif($sys_class_name=='cmdb_ci_win_server') { // red
        $background = imagecolorallocate( $img, 200, 100, 100 );
    } else {
        $background = imagecolorallocate( $img, 200, 200, 200 );
    }

    $text_colour = imagecolorallocate( $img, 0, 0, 0 );
    $line_colour = imagecolorallocate( $img, 0, 0, 0 );
    # If this should be a blank space.. make a transparent 'server' to fill the gap
    if ((strlen($text) == 0) or strstr($text, 'blank')) {
        imagecolortransparent ($img, $background);
    } else {
        imageCenterString($img, 5, $text, $text_colour);
        imageline ($img, 0,0,200,0, $line_colour);
        imageline ($img, 0,imagesy($img)-1,200,imagesy($img)-1, $line_colour);
    } // end if
} // end function

function imageCenterString(&$img, $font, $text, $color) {
    if($font < 0 || $font > 5){ $font = 0; }
    $num = array(array(4.6, 6),
                 array(4.6, 6),
                 array(5.6, 12),
                 array(6.5, 12),
                 array(7.6, 16),
                 array(8.5, 16));
    $width = ceil(strlen($text) * $num[$font][0]);
    $x     = imagesx($img) - $width - 8;
    $y     = Imagesy($img) - ($num[$font][1] + 2);
    imagestring($img, $font, $x/2, $y/2, $text, $color);
} // end function

?>