I'm looking at what the best way would be to design a cimi system's subcollections (SystemMachine and SystemVolume in particular), and their mapping to the drivers.
Retrieval of a system (or collection of systems), gives a response that includes e.g. its machines: <machines href="http://cimi.example.org/systems/system1/machines"; /> Listing the system's machines, should return a collection of SystemMachines, with references to the actual machines. <Collection xmlns="http://schemas.dmtf.org/cimi/1"; resourceURI="http://schemas.dmtf.org/cimi/1/SystemMachineCollection";> <id>http://localhost:3001/cimi/systems/system1/machines</id> <count>2</count> <SystemMachine> <id>http://localhost:3001/cimi/systems/system1/machines/inst0</id> <name>Mock Instance With Profile Change</name> <description>SystemMachine inst0 for System system1</description> <machine href="http://localhost:3001/cimi/machines/inst0"; /> <operation rel="delete" href="http://localhost:3001/cimi/systems/system1/machines/inst0"; /> </SystemMachine> ... I'm considering several ways to implement this: 1. From system_machine#self.find, passing the system_id to the existing driver.instances method to list only the instances of that system, then convert the instances into a SystemMachineCollection. This would be the most efficient way for fgcp. 2. Introduce a driver.system_machines method and leave it up to the driver how to retrieve the instances. A disadvantage is that each supporting driver relying on instances() would have to do the instance->machine conversion themselves. 3. Introduce a driver.system_instances method and leave it up to the driver how to retrieve the instances belonging to this system. The instance->machine conversion would be done in system_machine#self.find as in 1. A disadvantage of this is the mixture of cimi and DC concepts. I prefer 1. Possibly by adding a "system" feature for the drivers that support this in their instances (and storage_volumes, keys?) methods, so that we can use the DB for drivers that don't. What do you think? Regards, Dies Koper -- Dies KÖPER Software & Solutions Architect Fujitsu Australia Software Technology (FAST) - Cloud Computing Tel. +61 2 9452 9061 (Fujitsu internal 7985-29061) di...@fast.au.fujitsu.com
