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Magnolia.home

The Magnolia webapp should webapp should be markable as read-only; module jars should be loadable from outside the webapp folder (we don't want to(can not) write inside /WEB-INF/). Other files (repository, indexes, cache, ...) should also be written outside the webapp. See MAGNOLIA-2170@jira and the linked user-list thread for some background discussion. | | | | |

This is independent of a library choice, but should be implemented prior to actual module download/upgrade. (we'll need to download the modules, extract bundles, ...)
MAGNOLIA-2170@jira

Split core

Magnolia-core will probably have to remain in the webapp folder: extract more out of core, so that it can also benefit from easy updates. | | | | |

Hot (re)deploy

 No need to restart the app/appserver to deploy a module update. ("updates are ready: \[apply now, silently\] or \[click here for switching to the update UI when ready\]"; alternatively, we could maybe make it so that the system still works while updates are being applied, and switches "atomically" at the end? - or at least provide a configurable temp page for public instances) 
 

We can already restart a module. Missing points: *

• restart

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• this

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• module's

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• dependencies

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• in

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• the

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• appropriate

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• order.

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• (restarting

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• all

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• is

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• probably

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• good

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• enough)
• load modules in an isolated classloader, so hopefully, we can swap to the new jars once they're downloaded. We have some experience w/ classloaders, see magnolia-tools ! (+include classloader debug info in the diagnostics module !)
• what happens to the public site while updating (is Magnolia accessible, do we have a temp page) | out of scope | | | |

Uninstall modules

Most of our modules are actually fairly easily uninstallable (see docu, it's mostly removing the jar and removing a few specific nodes), so this should be feasible. Provide backup of removed nodes for safety. Uninstalls could be "automatic" when a jar removal is detected (i.e when restarting the server) or done through some form of gui. Potential implementation would imply serializing the tasks-for-uninstalling at install time. (store result of ModuleVersionHandler.getUninstallTasks())
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The current update UI is totally open: provide a better/configurable page for public instances while updates are being performed. | | | | MAGNOLIA-1629@jira |

System workspace

We're currently store the module related information in the configuration workspaces, in various places: current module version under /module/xyz/version, backup of some config nodes under /server/install/backup, information about extracted files under /server/install/mgnl-files. We could instead use a specific workspace. | | | | |

External libraries

Modules need to be bundled with 3rd party libs (e.g Quartz with the Scheduler module). Current limitation of our module system is that we don't provide any "check" - e.g Scheduler module bluntly fails to start after installation; thus blocking the complete system. | | | | |

UI

Missing dependencies should be reported in the ui.

Security: the current update UI is totally open: provide a better/configurable page for public instances while updates are being performed. See MAGNOLIA-1629@jira.

Module descriptions

For download and install, we'll want to display decent module descriptions etc, maybe even screenshots. This implies we might need to add some features to the module descriptor. | | | | |

Server side

Where and how do we deploy and publish modules. | | | | |

Versions, dependencies

Our current dependency system can state a minimal required version (i.e module X depends on Y 1.3 and up and on core 4.1 and up. Somehow, we'll have to be able to also say that module X 1.2 will not work anymore with Y 1.5, which is not something that we can determine when X is released. So this is probably something that needs to happen on the server-side of things. | | | | |

Detecting inter-module dependencies

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Handling of module's own dependencies (i.e non-Magnolia)

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• Examples of existing implementations of such features: Confluence, Hudson, ...
• We could(should) also evaluate OSGi, although my feeling is that it is very complex and bulky, and will incur more cost than bring benefits. Somehow I hope I'm wrong.
• We might also want to evaluate how to re-use the Maven infrastructure. This might be particularly interesting since our builds already deploy to Maven repositories, we might not have to invent much as far as getting new modules goes ! The current effort is going into "Mercury", which as far as I understand, will be a foundation block for Maven 3:
  • http://svn.magnolia-cms.com/svn/internal/testing-mercury/
  • http://www.sonatype.com/people/2008/11/what-is-mercury/
  • http://maven.apache.org/mercury/index.html
  • http://docs.codehaus.org/display/MAVEN/Mercury
  • http://docs.codehaus.org/display/MAVEN/HowTo+use+Mercury+for+accessing+repositories
  • http://repo2.maven.org/maven2/org/apache/maven/mercury/ (1.0-alpha-5 is available at the time of writing)
  • http://svn.eu.apache.org/viewvc/maven/mercury/trunk/

GUI

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