Set and modify system options
Ubuntu Core supports a set of system-wide options that allow you to customise your snap and core environment. See Configuration options for which options are supported.
As with Configuration in snaps, these options are changed with the snap set and snap get commands, but with a target of system instead of a specific snap:
snap set system some.option="some value"
snap get system some.option
Configuration options can be unset by either passing their names to the unset command or by adding an exclamation mark (!) to the end of an option name: (from snapd 2.41+):
snap unset system some.option
or
snap set system some.option!
Typing snap get system outputs a top-level view of system-wide option categories which can be added as arguments to view their contents:
$ snap get system
Key Value
experimental {...}
refresh {...}
seed {...}
$ snap get system experimental
Key Value
experimental.hotplug true
experimental.layouts true
The entire set of system configuration options can be dumped as JSON by adding the -d option:
$ snap get -d system
{
"experimental": {
"hotplug": true,
"layouts": true,
"quota-groups": true
},
"refresh": {
"last": "2017-05-25T09:03:58.664837614+01:00",
"retain": 2
},
"seed": {
"loaded": true
},
"system": {
"hostname": "neon",
"network": {},
"timezone": "UTC"
}
}
See Gadget snaps for details on how to create a default set of configuration values for a device.