datalinker

datalinker provides various facilities for discovering and referring to data products and services within the Rubin Science Platform. It is deployed via Phalanx and depends on other Phalanx services such as Gafaelfawr for authentication.

The API provided by datalinker is primarily based on the IVOA DataLink standard, but it also provides some related service discovery facilities beyond the scope of that standard.

• Implements a "links" endpoint, providing a variety of file and service links given an ID for an image in the RSP image services. This endpoint is the target of the access_url column in the RSP ObsTAP service.

• Implements a HiPS list service, which collects the properties files of the HiPS data sets available in a Science Platform deployment, adds their canonical URLs, and serves the resulting collection from an in-process cache.

• Implements a variety of "microservice" endpoints to be used as the targets of DataLink service descriptors, many of which will rewrite simple service-descriptor-friendly URL APIs into more complicated queries to a back end. Some of these will be associated with entries in the tables from the "links" endpoint for images; some will be used with service descriptors in catalog query results.

datalinker implements version 1.0 of the IVOA DataLink standard with the following known exceptions:

• The content parameter is not set in the MIME type of the reply.
• The links endpoint only supports GET, not POST.
• /availability and /capabilities are not yet implemented.
• Errors are formatted as JSON rather than as VOTables.

datalinker is developed with the Safir framework.