snap `unset` is doing `set` with an empty value about edgex-snap-hooks HOT 8 CLOSED

This is an snap control or snapd issue. IMO, the unset should remove the key-value or set the value to null. Setting it to empty object is problematic because the original value may have been an string.

from edgex-snap-hooks.

WIth this, snap unset doesn't do work anymore.

Maybe some other part of the code is checking if the value is nil and setting it to the empty object.

from edgex-snap-hooks.

EdgeX does not have any control of what is set and unset. Snapd manages those.

You are testing something different. The behavior is the same:

$ snap set lxd x.y="hi"
$ snap get lxd -d
{
	"x": {
		"y": "hi"
	}
}

$ snap unset lxd x.y
$ snap get lxd -d
{
	"x": {}
}

from edgex-snap-hooks.

Agree, I think the snapd set the value to nil anyway. Unset should consider whether the key exists or not first.
https://github.com/snapcore/snapd/blob/master/cmd/snap/cmd_unset.go#L67-L69

from edgex-snap-hooks.

Agree, I think the snapd set the value to nil anyway. Unset should consider whether the key exists or not first. https://github.com/snapcore/snapd/blob/master/cmd/snap/cmd_unset.go#L67-L69

Perhaps it should be deleted instead: delete(patchValues, confKey)

from edgex-snap-hooks.

	patchValues := make(map[string]interface{})
	for _, confKey := range x.Positional.ConfKeys {
		// patchValues[confKey] = nil
		delete(patchValues, confKey)
	}

WIth this, snap unset doesn't do work anymore.

from edgex-snap-hooks.

Need to report on Snapd's issue tracker.

from edgex-snap-hooks.

It might be an EdgeX specific issue:

$ snap get -d lxd
{}
$ snap unset lxd service-port
$ snap get -d lxd
{}

from edgex-snap-hooks.