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• This release has been built against Java 8
• Downloads [1]
• Javadocs [2]

Team

Release

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Managers

• Nick Ruest
• Esmé Cowles

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Developers

• A. Soroka

• Unknown User (acoburn)

• Andrew Woods

• Andy Wagner

• Bethany Seeger

• Esmé Cowles

• Jared Whiklo

• Michael Durbin

• Mohamed Mohideen Abdul Rasheed

• Nianli Ma

• Nick Ruest

• Osman Din

• Peter Eichman

• Ralf Claussnitzer

• Yinlin Chen

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Issue Reporters

• A. Soroka
• Unknown User (acoburn)
• Andrew Woods
• Bethany Seeger
• Unknown User (daniel-dgi)
• David Wilcox
• Esmé Cowles
• Jared Whiklo
• Justin Coyne
• Longshou Situ
• Michael Durbin
• Mohamed Mohideen Abdul Rasheed
• Monika Mevenkamp
• Nick Ruest
• Osman Din
• Peter Eichman
• Ralf Claussnitzer
• Rob Sanderson
• Steven Anderson...

Summary

The Fedora 4.45.0 release furthers several major objectives:

• Tighten the definition of the RESTful application programming interface (API)
• Further align this API to community standards, including the Linked Data Platform [3] (LDP) and Web Access Control [4] (WebAC)Improve tooling for legacy Fedora repositories to Fedora4
• Enhance preservation capabilities and related documentation
• Improve tooling for external services live in the ecosystem around the repository
• Fix bugs

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• HTTP GET requests on descriptions of NonRDF resources (i.e. binaries) now return RDF triples that all have the NonRDF resource as the subject, whereas previously the returned RDF contained a mix of subjects in the response: some subjects were the NonRDF resource, some subjects were the NonRDF description resource
• When requesting the fixity service [5] be performed on a binary resource, the "status" of the fixity result has been changed in this release from: "fedora:status" to "premis:hasEventOutcome"

Although not a backwards incompatible update in the 4.4.0 release, it should be noted that the Import and Export services [6] have been deprecated due to their reliance on a JCR serialization versus an RDF-centric approach. These services will be supplanted by externalized machinery that transacts in RDF.

Updates

Community Registry

To minimize the barriers to using Fedora, a free, open source application, there is no required "registration" process. However, it is extremely beneficial to the broader Fedora community if we collectively aggregate some minimal details describing our respective repository installations.

DuraSpace maintains a registry [7] of installations that is populated on a voluntary basis. The 4.4.0 release raises the visibility of that registry, and hopefully the likelihood that repository managers will self-register [8] in it, by adding a link on the Fedora installation spash-page requesting exactly that.

Application Programming Interface

One of the technical priorities [95] of Fedora is to define a well-specified application programming interface (API) against which client applications can be written and future server-side implementations can be created. This Fedora API should be clear and detailed enough such that a cooresponding corresponding technology compatibility kit [106] (TCK) would be able to indicate if the any Fedora implementation fullfills fulfills or diverges from the specification. With this in mind, several issues where were addressed in this release that clean up Fedora's RESTful interaction and tease out the non-core aspects of the Fedora ontology [11].

Linked Data Platform alignment

Fedora is a Linked Data Platform (LDP) server implementation. This release fixes resolves a few bugs bug that relate relates to the interactions that an LDP client should expect.

Upgrading and Migrating

A primary focus of the ongoing Fedora effort is to facilitate the upgrade/migration of Fedora3 repositories to Fedora4. To this end, a couple of improvements have been incorporated into the "migration-utils [127]" upgration utility.

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, the most notable of which is enabling the utility to optionally be configured with authorization credentials.

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Preservation

One of the exciting capabilities that Fedora enables is the creation of distributed, asynchronous, message-driven services that are external to the core repository but are triggered by repository events. This release further improves the deployment and runtime configurability of the Fedora-related Apache Camel-based [13] features. In support of Fedora's role in the preservation stack, this release includes investigation and documentation around backup and restore strategies for Fedora's datastore. By default, the database that Fedora currently is configured to use is LevelDB [8]. This release includes documentation and recommendations for performing backup and restore of the internal data Fedora uses in maintaining state.

Web Access Control

Web Access Control

Following the initial implementation of the Web Access Control [9] authorization module, this release furthers that effort with several fixes and improvements.  Enhancements include:

• WebACLs can now apply to binary resources

• An HTTP header, 'On-Behalf-Of', can optionally be configured to offer delegated authorization (documentation [10])

• A WebACL can be placed on the server acting as the final backstop for authorization decisions for resources that have no other effective WebACL (documentation [11])
• WebACLs can now include references to 'agentClass' Fedora resources as defined in the Web Access Control specification (documentation [12])
• An HTTP 'Link' header is included in responses to protected resources pointing to the effective WebACL

Additional documentation of Fedora's implementation of Web Access Controls is available on the wiki [13]A significant community success that is found in this release is an initial implementation of an Web Access Control [14] authorization module. This authorization module enables the establishment of access policies modeled as linked data. This feature was initiated, planned, designed, and implemented by a group of community stakeholders.

Modularity

From the perspectives of code maintainability, intelligibility, replaceability, and clearly defined separation of responsibility, significant focus continues towards increasing the modularity of Fedora. In this release, this effort can be seen in the extraction of the 'transform' and 'id minting' modules into their own projects, and the decoupling of project dependencies.

HTML User Interface

This release includes several useful updates to the HTML user interface:

• Ability to create versions in the HTML UI
• Auto-populate binary resource's 'educore:filename' property with name of file uploaded in the HTML UI
• Limit the number of children of any given resource shown in the HTML UI to 100

Housekeeping and Bugfixes

Numerous refactorings, bugfixes, and clean-up tasks were addressed in this release:

References

[1]  https://wiki.duraspace.org/display/FF/Downloads
[2]  http://docs.fcrepo.org/
[3]  http://www.w3.org/TR/ldp/
[4]  http://www.w3.org/wiki/WebAccessControl
[5]  https://wiki.duraspace.org/display/FEDORA44FF/RESTful2015+HTTP-+API2016+-Technical+FixityPriorities
[6]  https://wikien.duraspacewikipedia.org/display/FEDORA44/RESTful+HTTP+API+-+Export+and+Importwiki/Technology_Compatibility_Kit
[7]  httphttps://wwwgithub.duraspace.org/registry/fedoracom/fcrepo4-exts/migration-utils
[8]  httphttps://www.duraspace.org/register-repositorygithub.com/dain/leveldb
[9]  httpshttp://wikiwww.duraspacew3.org/display/FF/2015+-+2016+Technical+Prioritieswiki/WebAccessControl
[10] https://enwiki.wikipediaduraspace.org/wiki/Technology_Compatibility_Kitdisplay/FEDORA45/Principal+Providers#PrincipalProviders-DelegateHeaderPrincipalProvider
[11] httphttps://fedorawiki.duraspace.infoorg/definitionsdisplay/v4/2015/07/24/repositoryFEDORA45/Default+Filesystem-based+Policy
[12] https://github.com/fcrepo4-exts/migration-utilswiki.duraspace.org/display/FEDORA45/How+to+Use+WebAC+agentClass+Groups
[13] httphttps://camelwiki.apacheduraspace.org/
[14] http://www.w3.org/wiki/WebAccessControl
 display/FEDORA45/WebAC+Authorization+Delegate