ServiceDiscovery

One problem that faces all WebDAV clients is where to find the root of the WebDAV hierarchy. Often clients assume that this will be the root resource, but this is frequently not true and presents problems for hosted servers which may be beneath another authorities root.

Support for .wellknwon_ URLs is implemented as of r4364 (121015c9a905) pre-0.1.49.

RFC6785 Well Knowns

The solution proposed by RFC5785 is the use of the .well_known/resource URL to discover the root of the resource tree. This is in keeping with the customary UNIX tradition that resources whose name begins with a dot are hidden. The value of resource is not defined by the RFC; but a convention of caldav and carddav is used, at least by iOS devices.

URL	Resource
.well_known/caldav	CALDAV resources
.well_known/carddav	CardDAV resources

These URLs should perform a 301 HTTP redirect to the real location of the resources if they are present elsewhere.

Service Discovery via DNS

SRV and TXT records can also be used by clients to discover the location or resources. For example the following DNS records indicate the location of CardDAV and CALDAV services over SSL.

DNS Records
_carddavs._tcp 86400 IN SRV 10 20 443 coils.example.org.
_carddavs._tcp 86400 IN TXT dav=/dav
_caldavs._tcp 86400 IN SRV 10 20 443 coils.example.org.
_caldavs._tcp 86400 IN TXT dav=/dav