[Engine-devel] engine-config behaviour on -g by alternateKey

[Martin Betak]

Hi All,

I've been working on the ability to set keyboard layout for VNC server as per each individual VM. Currently the only option is to use engine-config to set the value globally, e.g. engine-config -s VncKeyboardLayout=en-us. After adding this option to database and respective entities there were raised valid concerns about why is this option called VncKeyboardLayout and not just KeyboardLayout as it applies to SPICE equally (note that also VDSM calls this config value as 'keyboardLayout'). 
So to achieve consistency I also renamed it in engine-config.properties and set KeyboardLayout.alternateKey=VncKeyboardLayout. This indeed works for setting (engine-config -s VncKeyboardLayout=en-us sets KeyboardLayout and engine-config -g KeyboardLayout works but it is unable to read the value by the alternateKey) 
engine-config -g VncKeyboardLayout fails with "no such entry with default version" in the method EngineConfigLogic.printAllValuesForKey as it is passing the user given key name directly to database which returns zero results. Setter methods such as EngineConfigLogic.persistValue use the entity ConfigKey constructed from the user given key-name which correctly constructs appropriate ConfigKey even when given alternateKey name. 

So I wanted to ask whether this is the desired behaviour (set by alternateKey name but get only by the primary) or is this a bug? I have also simple patch that fixes this and enables also getting the config value by alternateKey.

Thank you