dCache CTA integration

gRPC based frontend for integration with dCache 7.2.2 and later. This is thin layer that only populates CTA catalog and scheduler queue. THe connection between a CTA and a dCache instance maintained by hsm URI, for example:

osm://cta/00001D43C0C086CA459298C634D67F68AB6B?archiveid=8402

where 00001D43C0C086CA459298C634D67F68AB6B corresponds to the dCache unique file id (so called pnfs id) and 8402 corresponds to the archive id within CTA catalog.

NOTE: the original file name, owner and owner group are not propagated by dCache to CTA.

Configuration

As mentioned above, the cta-dcache interface requires only connection to the CTA catalog and the scheduler. Those configurations are taken from /etc/cta/cta-catalogue.conf and /etc/cta/cta.conf. The TPC port number used to accept dCache requests is specified in /etc/sysconfig/cta-dcache and defaults to 17017.