RackTablesDevelGuide

Working with SVN repository

getting a working copy of maintenance line

# Anyone can read from the repository, but writing requires an account on the server.
svn co https://racktables.svn.sourceforge.net/svnroot/racktables/branches/RackTables/maintenance-0.17.x/

# Above command is for the maintenance line. For the trunk (see roadmap picture for exact
# difference between two) respective command is:
svn co https://racktables.svn.sourceforge.net/svnroot/racktables/trunk/RackTables/

editing files

Use your favourite editor. Consider existing code style (tabbed indentation, K&R-styled curly braces).

viewing exact changes

svn stat
svn diff

submitting work

# if you have an account
svn commit

# and if you don't
svn diff > my-cool-feature.patch
# send the patch file by e-mail

Cutting a release

pre-release checklist

First make sure, that all necessary changes are already committed into the repository:

• Update inc/config.php:$max_dict_key.
• Function database.php:getDictStats() must indicate all chapters, which belong to dictionary in tarball. Otherwise the stats are shown wrong.
• All release notes, if any, must appear both in upgrade script and in the README.
• Add current date to the version line in !ChangeLog.
• Make sure, that upgrade.php has new version listed in $versionhistory and executeUpgradeBatch(). It is normal to accumulate updates in executeUpgradeBatch() long before the release, this way on the release day you will have nothing to do in upgrade.php. But if you had no changes to DB since the last release, you are likely to see there changes missing. Just make sure the new version is in both places anyway.
• Bump up CODE_VERSION in inc/config.php and DB_VERSION in install/init-dictbase.sql. DON'T do this unless you really intend to make a release right now.
• svn stat; svn commit

Then export from the trunk (or maintenance branch) and test the codebase.

• The source must be installable from the web. Click next-next-next and you're done. Dump the DB.
• Demo data must also be loadable and functional.
• The source must detect and upgrade the previous release correctly. Load the last release with its demo data, then upgrade it and dump the DB. Now compare to the previous dump, there must be no meaningful differences.

mysqldump --extended-insert=FALSE --order-by-primary racktables > ~/tmp/dump-upgraded.sql
mysqldump --extended-insert=FALSE --order-by-primary racktables > ~/tmp/dump-fresh.sql
diff -u ~/tmp/dump-fresh.sql ~/tmp/dump-upgraded.sql

• Now click a couple of links.
• Look into the error log of the server you used for the tests. There shouldn't be any messages produced by any test.

The above may happen repeated more, than once, until everything is fixed consistently.

the release itself

# from trunk (like early 0.16.x):
svn cp https://racktables.svn.sourceforge.net/svnroot/racktables/trunk/RackTables https://racktables.svn.sourceforge.net/svnroot/racktables/tags/RackTables-X.Y.Z
# from maintenance (like 0.17.x):
svn cp https://racktables.svn.sourceforge.net/svnroot/racktables/branches/RackTables/maintenance-X.Y.x https://racktables.svn.sourceforge.net/svnroot/racktables/tags/RackTables-X.Y.z

rolling out

• Make a tarball:

svn export https://racktables.svn.sourceforge.net/svnroot/racktables/tags/RackTables-X.Y.z
tar czf RackTables-X.Y.z.tar.gz RackTables-X.Y.z

• Upload the tarball onto the distibution site.
• Update the live demo page: create a new database, export source tree, add a crontab line. Let old demo run for a couple of days more.
• Update Trac records (roadmap is updated from web):

[root@racktables ~]# trac-admin /srv/trac/
Welcome to trac-admin 0.10.5
Interactive Trac administration console.
Copyright (c) 2003-2006 Edgewall Software

Type:  '?' or 'help' for help on commands.

Trac [/srv/trac]> version add X.Y.Z YYYY-MM-DD

• Edit /var/www/vhosts/racktables.org/header.php to update $lastrelease. Make sure "download" and "demo" do work.
• Write a Freshmeat release announce.
• Send a letter to the racktables-users list, if necessary.

Config options

Variables are stored in the Config SQL table:

mysql> describe Config;
+-------------+-----------------------+------+-----+---------+-------+
| Field       | Type                  | Null | Key | Default | Extra |
+-------------+-----------------------+------+-----+---------+-------+
| varname     | varchar(32)           | NO   | PRI |         |       | 
| varvalue    | varchar(255)          | NO   |     |         |       | 
| vartype     | enum('string','uint') | NO   |     | string  |       | 
| emptyok     | enum('yes','no')      | NO   |     | no      |       | 
| is_hidden   | enum('yes','no')      | NO   |     | yes     |       | 
| description | text                  | YES  |     | NULL    |       | 
+-------------+-----------------------+------+-----+---------+-------+
6 rows in set (0.00 sec)

Options are read and written with getConfigVar() and setConfigVar() functions respectively. The current naming convention for new options is to use descriptive expressions in ALL_CAPITAL_LETTERS with spaces REPLACED_WITH_UNDERSCORES. When adding a new option, check the following places:

1. upgrade.php
2. install/init-dictbase.sql
3. inc/ophandlers.php:resetUIConfig()

Default values must match regardless of the way they were set: initial setup, upgrade or UI reset.

Exceptions and error handling (in development)

Error handling now can be done by exceptions mechanism. index.php and process.php have been wrapped in

ob_start(); 
try{
  ...
  ob_end_flush();
} catch {
  print_error_nicely();
}

kind of code, so every exception you miss and not catch will be printed instead of the page that had to be printed.

This saves a lot of code, take a look at a function

// before

function commitUpdateDictionary ($chapter_no = 0, $dict_key = 0, $dict_value = '')
{
        if ($chapter_no <= 0)
        {
                showError ('Invalid args', __FUNCTION__);
                die;
        }
        global $dbxlink;
        $query =
                "update Dictionary set dict_value = '${dict_value}' where chapter_id=${chapter_no} " .
                "and dict_key=${dict_key} limit 1";
        $result = $dbxlink->query ($query);
        if ($result == NULL)
        {
                showError ('SQL query failed', __FUNCTION__);
                die;
        }
        return TRUE;
}

// and after

function commitUpdateDictionary ($chapter_no = 0, $dict_key = 0, $dict_value = '')
{
        if ($chapter_no <= 0) 
                   throw InvalidArgException('$chapter_no', $chapter_no);
        Database::updateWhere(array('dict_value'=>$dict_value), 'Dictionary', array('chapter_id'=>$chapter_no, 'dict_key'=>$dict_key));
        return TRUE;
}

Function Database::updateWhere throws an exception if query is bad, and you can catch it if you want and handle it as necessary, or you can just ignore it and application will display error message with s stacktrace and such.

Exceptions registered so far:

class name	by	when
NotAuthorizedException		Authentication failed or user is not authorized to view current page
CodeCompilationError		RackCode compilcation failed
RealmNotFoundException		Realm not found
EntityNotFoundException		when an entity cannot be found in the database
NotUniqueException		when a record cannot be INSERTed into SQL table due to UNIQUE KEY constraint
InvalidArgException	lots of places	when at least one of the arguments provided to a function has invalid value
InvalidRequestArgException	usually thrown by assert*Arg() functions	wrong argument in Request
Exception		When it's not worth to create a special exception class

---

RackCode

BNF/regexp	description
ID ::= ^[[:alnum:]]([\. _~-]?[[:alnum:]])*$	identifier
PREDICATE ::= [ID]	identifier in brackets
DEFINE ::= define PREDICATE
TAG ::= {ID}	identifier in curly braces
AUTOTAG ::= {$ID}	identifier in curly braces, starting with dollar sign
CTXMOD ::= clear | insert TAG | remove TAG	context modifier
CTXMODLIST ::= CTXMODLIST CTXMOD | CTXMOD	context modifier list
UNARY_EXPRESSION ::= true | false | TAG | AUTOTAG | PREDICATE | (EXPRESSION) | not UNARY_EXPRESSION
AND_EXPRESSION ::= AND_EXPRESSION and UNARY_EXPRESSION | UNARY_EXPRESSION	logical AND
EXPRESSION ::= EXPRESSION or AND_EXPRESSION | AND_EXPRESSION	logical OR
GRANT ::= allow EXPRESSION | deny EXPRESSION
DEFINITION ::= DEFINE EXPRESSION
ADJUSTMENT ::= context CTXMODLIST on EXPRESSION
CODETEXT ::= CODETEXT GRANT | CODETEXT DEFINITION | CODETEXT ADJUSTMENT | GRANT | DEFINITION | ADJUSTMENT	RackCode permission text

Comments in RackCode last from the first # character to the end of current line and are filtered out automatically:

allow {tech support} # or {admins} <--- note where comment starts
and {assets} # <--- this is still a part of "allow" statement

deny {guests}

API

Hello, World!

To enable all RackTables functions and load all necessary system data, it is enough to include one file.

<?php

include ('inc/init.php');
// do something

?>

There is a special parameter, which tells, if current file is intended to be run by web-server or from a command line. In the latter case neither authentication nor authorization is performed.

<?php

$script_mode = TRUE;
include ('inc/init.php');

echo "I am a crontab script!\n";
// do something

?>

Realms

There are several principal realms in !RackTables database. Any realm contains zero, one or more records. Each such record is addressed by its ID (primary key).

object

All servers, switches, UPSes, wireless, cable management and any other stuff, which is viewed and managed on the main "Objects" page.

ipv4net

All IPv4 networks.

user

All local accounts. There is at least one local account in any RackTables system (admin). There may be more.

rack

All racks.

file

All files.

ipv4vs

All IPv4 virtual services.

ipv4rspool

All IPv4 real server pools.

function scanRealmByText ($realm, $ftext = "")

realm

String equal to one of the realms shown above.

ftext

Optional filter text. If this text is empty, all records of the realm are returned. If it is not empty, it is interpreted as a !RackCode expression. This expression is then evaluated against each record of the realm and only those records, for which the filter returned TRUE, are returned.

<?php

include ('inc/init.php');

$allusers = scanRealmByText ('user');
$smallnetworks = scanRealmByText ('ipv4net', '{small network}');
$unmounted_objects = scanRealmByText ('object', '{$unmounted}');

?>

function spotEntity ($realm, $id)

This is the right function to get information about some record, for which you know where it belongs to and what its key value is. If this information isn't available, it has to be discovered somehow first.

realm

Realm name.

id

Record number (key value, ID...).

<?php

include ('inc/init.php');

$adminuser = spotEntity ('user', 1); // Admin account is always number 1.
$myspecialfile = spotEntity ('file', 12345);
$serverinfo = spotEntity ('object', 67890);

?>

function amplifyCell (&$record, $dummy = NULL)

It is assumed, that spotEntity() loads only basic data about the record requested. "Basic" means enough for renderCell() to do its job or to render a row in a table. To get detailed information about the "cell" it is necessary to execute amplifyCell() on it:

<?php
include ('inc/init.php');

$adminuser = spotEntity ('user', 1); // Admin account is always number 1.
amplifyCell ($adminuser);

$unmounted_objects = scanRealmByText ('object', '{$unmounted}');
array_walk ($unmounted_objects, 'amplifyCell');
?>

function renderCell ($cell)

Render cell structure as a rectangular block with icon, name, tags and other information. Available since 0.17.2.

Dictionary

Since release 0.17.2 all records are stored in file {{{inc/dictionary.php}}}: {{{ $dictionary = array ( 1 => array ('chapter_id' => 1, 'dict_value' => 'BlackBox'), 2 => array ('chapter_id' => 1, 'dict_value' => 'PDU'), 3 => array ('chapter_id' => 1, 'dict_value' => 'Shelf'), 4 => array ('chapter_id' => 1, 'dict_value' => 'Server'), 5 => array ('chapter_id' => 1, 'dict_value' => 'DiskArray'), 6 => array ('chapter_id' => 1, 'dict_value' => 'TapeLibrary'), 7 => array ('chapter_id' => 1, 'dict_value' => 'Router'), 8 => array ('chapter_id' => 1, 'dict_value' => 'Network switch'), 9 => array ('chapter_id' => 1, 'dict_value' => 'PatchPanel'), 10 => array ('chapter_id' => 1, 'dict_value' => 'CableOrganizer'), 11 => array ('chapter_id' => 1, 'dict_value' => 'spacer'), 12 => array ('chapter_id' => 1, 'dict_value' => 'UPS'), [...] }}}

meaning of chapter ID

id 

wikilinks

It is possible to render a record as an URL: {{{ http://somewhere/ }}}. However, it is up to the editor, if to include URL into description or not. URLs can be added, changed and removed from particular records later, if it makes sense.

G-markers

Text before the marker is always used for OPTGROUP in SELECT element. The difference is in the way the text is rendered as a plain text or a clickable URL. GSKIP makes OPTGROUP name to be skipped. GPASS passes OPTGROUP name on the text: {{{

   719 => array ('chapter_id' => 24, 'dict_value' => ' http://cisco.com/en/US/products/ps9438/index.html'),
   720 => array ('chapter_id' => 13, 'dict_value' => ' http://openbsd.org/33.html'),

}}}

Image(dictionary-G-markers.png, nolink)