1f4f2643aSPatrick Williams# dbus usage 2f4f2643aSPatrick Williams 3e2415fa7SEd TanousThe following are guidelines for bmcweb's use of DBus to construct Redfish 4e2415fa7SEd Tanousschemas: 5e2415fa7SEd Tanous 6e2415fa7SEd Tanous- Do not require (ie set 500 internal error on) an implementation present a 7e2415fa7SEd Tanous property that wasn't in the first commit of the interface unless it can be 8e2415fa7SEd Tanous verified that _all_ OpenBMC implementers of the interface support that 9e2415fa7SEd Tanous property. 10e2415fa7SEd Tanous- If an implementation presents a property that doesn't match the type specified 11*8ece0e45SEd Tanous by the interface at any version, it shall be reported as a 500 error. 12e2415fa7SEd Tanous- If the DBus interface definition has an "unknown" or "unspecified" value, 13e2415fa7SEd Tanous detecting these will omit the property from the Redfish tree, in line with the 14e2415fa7SEd Tanous Redfish specification. 15e2415fa7SEd Tanous- All DBus interfaces on all object paths are optional. An object missing an 16e2415fa7SEd Tanous interface is never an error, and shall simply omit the relevant properties 17e2415fa7SEd Tanous and/or actions from that Redfish Resource. 18e2415fa7SEd Tanous- bmcweb will code to the DBus interface itself. This means that daemons are 19e2415fa7SEd Tanous expected to handle functionally bad, but DBus-correct input in their own 20e2415fa7SEd Tanous process, and return appropriate return codes. This is done to reduce the 21e2415fa7SEd Tanous duplication in input processing between the various user-facing daemons. 22e2415fa7SEd Tanous- There are interfaces for which there is an expectation that there will only 23e2415fa7SEd Tanous ever be one producer in the project (ex bmc networking, user management). In 24e2415fa7SEd Tanous these cases, it is desirable to call the daemon by well known name directly. 25e2415fa7SEd Tanous Bmcweb APIs should call the mapper in cases where it's reasonably expected 26e2415fa7SEd Tanous that multiple implementations exist (ex, CPU management, Sensors). 27