Reference yang:
container vpn-interfaces {
description
"VPN is enabled on interfaces.";

list vpn-interface {
key "name";
max-elements "unbounded";
min-elements "0";
leaf name {
type leafref

{ path "/if:interfaces/if:interface/if:name"; }

}
leaf vpn-instance-name {
type string

{ length "1..40"; }

}
}
}

GET on URL http://localhost:8181/restconf/config/l3vpn:vpn-interfaces/ successful.

GET on URL http://localhost:8181/restconf/config/l3vpn:vpn-interfaces/vpn-interface/s1-eth1 fails with following error:
{
"errors": {
"error": [

{ "error-type": "protocol", "error-tag": "invalid-value", "error-message": "s1-eth1 from URI can't be resolved. " }

]
}
}

Other observations:
1. Read from datastore using JAVA APIs works fine.
2. No error observed in log file.