Drupal package management

Vladimir Zlatanov

What is this about?

• Current status
• Dependencies
• Installation strategies

Current status

Packages

• core
• modules
• theme engines
• themes

Current status

Versioning

• cvs
• core releases
• one module version per major core release

Current status

Locations

• core
• sites
• module directories
• theme directories

Status - Dependencies

• modules depend on core and other modules
• themes depend on theme engine and modules(at least some of them)
• stirr in versions - release and cvs
• more than 400 directories in contrib means a lot of potential modules

Dependencies

• api
• modules
• database schema

dependency.inc

• provides an api
• find what a package depends on
• perform operations based on dependency order - depth first graph walk
• isn't going to handle circular dependencies

dependency_process

/**
 * execute/process the dependencies

 * @param $stages the installation/process stages
 * @param $modules the modules to install
 * @param $callback the callback to call, takes $stage,$module as parameters

 * @return $trace - the callstack ( will be deprecated in production )
 */
function dependency_process($stages, $modules, $callback,$validate_callback,$error_callback) {  

  $result = FALSE;
  
  foreach($stages as $stage) {
    foreach($modules as $module) {
      $result[$module] = _dependency_process( $stage, $module, $callback,
                         $validate_callback,$error_callback);
    }
  }

  return $result;
}
   

drupal dependency graph

drupal dependency graph (zoomed)

Packages

• make packages sexless - no differentiation between modules, themes, and others
• expose dependencies between the packages
• allow virtual packages
• add more meta-data
  • database schema
  • some classification or tagging

Metadata

• name
• description
• dependecies
• other metadata - application dependent

Control/Description file

inspired by Debian control file

module: news_page
repository: contrib
path: /home/vlado/src/drupal/contributions/modules/news_page
schema: 1
depends: feed,og,title,variable,content

module: naggregator
repository: contrib
path: /home/vlado/src/drupal/contributions/modules/naggregator
schema: 1
depends: feed,item,title,variable

Control/Description file

• easy to read and write by humans
• simple parser
• could be useful for different distributors
• doesn't exclude other alternative formats (XML based, etc...)

Virtual and Meta packages

• Virtual packages contain only dependencies to other packages
• Meta-packages contain dependencies to other packages and some configuration and/or data for the configuration of the dependent packages
• Bundles are virtual or meta packages
• Distributions provide a collection of packages tuned to the distribution's target market

Installation

• direct web-based, i.e. upload - configure
• indirect web-based, i.e. via a controller ala fantastico
• staged - local configure, upload, remote configure

Installation stages

• prepare package list
• download packages
• unpack
• configure packages

Direct web-based

• web interface
• downloads and unpacks packages
• setup the db
• configure the system

• userfriendly
• webserver insecure
• sources can be spoofed

Indirect web-based

• Separate super-site
• download once, install many
• userfriendly
• webinterface

Staged

• download locally
• prepare the install - db, options, generate the install script
• upload to server
• finalise the install - run the install script

Upgrades

• will make the upgrade process cleaner an more transparent
• each package will handle it's own upgrades
• allows the creation of "migration" packages
• finalise the install - run the install script

drpkg status

• generates control files, php code, etc...
• draws nice pictures
• serves as a testbed of dependency.inc
• will evolve into a staged install command line tool
• will package, re-package, ftp upload, remote install

Questions