Issue with JSON formatting when Requested-path ! = Response-prefix

[yashikakn]

When trying to retrieve ip-addresses data using GNMI subscribe request, I see the ip addresses data is received from the DUT (please refer to attached file <json.encoding.raw>) but looks like the tool has some issue with JSON formatting when Requested-path ! = Response-prefix.
(file <json.encoding.formatted>)

Here, requested path is :/interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]/

Same works with –encoding proto. Please refer to attached files < proto.encoding.raw, proto.encoding.formatted>

Sample outputs:

1. With encoding 'json'
   gnmic -a 10.92.196.149:50051 sub --path "/interfaces/interface[name="lo0"]/subinterfaces/subinterface[index=0]" -u root -p Embe1mpls --insecure --encoding json --mode once{
   "source": "10.92.196.149:50051",
   "subscription-name": "default-1652375785",
   "timestamp": 1652375789566454228,
   "time": "2022-05-12T10:16:29.566454228-07:00",
   "prefix": "interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]",
   "updates": [
   {
   "Path": "state/index",
   "values": {
   "state/index": 0
   }
   },
   {
   "Path": "state/description",
   "values": {
   "state/description": ""
   }
   },
   {
   "Path": "state/enabled",
   "values": {
   "state/enabled": 1
   }
   },
   {
   "Path": "state/name",
   "values": {
   "state/name": "lo0.0"
   }
   },
   {
   "Path": "state/ifindex",
   "values": {
   "state/ifindex": 16
   }
   },
   {
   "Path": "state/admin-status",
   "values": {
   "state/admin-status": "UP"
   }
   },
   {
   "Path": "state/oper-status",
   "values": {
   "state/oper-status": "UP"
   }
   },
   {
   "Path": "state/last-change",
   "values": {
   "state/last-change": 0
   }
   },
   {
   "Path": "state/logical",
   "values": {
   "state/logical": 1
   }
   }
   ]
   }
   {
   "source": "10.92.196.149:50051",
   "subscription-name": "default-1652375785",
   "timestamp": 1652375789570389796,
   "time": "2022-05-12T10:16:29.570389796-07:00",
   "prefix": "interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]",
   "updates": [
   {
   "Path": "ipv4/state/enabled",
   "values": {
   "ipv4/state/enabled": 1
   }
   },
   {
   "Path": "ipv4/state/mtu",
   "values": {
   "ipv4/state/mtu": 65535
   }
   }
   ]
   }
   {
   "source": "10.92.196.149:50051",
   "subscription-name": "default-1652375785",
   "timestamp": 1652375789572884485,
   "time": "2022-05-12T10:16:29.572884485-07:00",
   "prefix": "interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]",
   "updates": [
   {
   "Path": "ipv6/state/enabled",
   "values": {
   "ipv6/state/enabled": 1
   }
   },
   {
   "Path": "ipv6/state/mtu",
   "values": {
   "ipv6/state/mtu": 4294967295
   }
   }
   ]
   }

2. With encoding 'proto':
   gnmic -a 10.92.196.149:50051 sub --path "/interfaces/interface[name="lo0"]/subinterfaces/subinterface[index=0]" -u root -p Embe1mpls --insecure --encoding proto --mode once
   {
   "source": "10.92.196.149:50051",
   "subscription-name": "default-1652375806",
   "timestamp": 1652375809449870735,
   "time": "2022-05-12T10:16:49.449870735-07:00",
   "prefix": "interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]",
   "updates": [
   {
   "Path": "state/index",
   "values": {
   "state/index": 0
   }
   },
   {
   "Path": "state/description",
   "values": {
   "state/description": ""
   }
   },
   {
   "Path": "state/enabled",
   "values": {
   "state/enabled": true
   }
   },
   {
   "Path": "state/name",
   "values": {
   "state/name": "lo0.0"
   }
   },
   {
   "Path": "state/ifindex",
   "values": {
   "state/ifindex": 16
   }
   },
   {
   "Path": "state/admin-status",
   "values": {
   "state/admin-status": "UP"
   }
   },
   {
   "Path": "state/oper-status",
   "values": {
   "state/oper-status": "UP"
   }
   },
   {
   "Path": "state/last-change",
   "values": {
   "state/last-change": 0
   }
   },
   {
   "Path": "state/logical",
   "values": {
   "state/logical": true
   }
   }
   ]
   }
   {
   "source": "10.92.196.149:50051",
   "subscription-name": "default-1652375806",
   "timestamp": 1652375809450004641,
   "time": "2022-05-12T10:16:49.450004641-07:00",
   "prefix": "interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]/ipv4/addresses/address[ip=10.255.2.76]",
   "updates": [
   {
   "Path": "state/ip",
   "values": {
   "state/ip": "10.255.2.76"
   }
   },
   {
   "Path": "state/prefix-length",
   "values": {
   "state/prefix-length": 32
   }
   },
   {
   "Path": "state/origin",
   "values": {
   "state/origin": "STATIC"
   }
   }
   ]
   }
   {
   "source": "10.92.196.149:50051",
   "subscription-name": "default-1652375806",
   "timestamp": 1652375809450139391,
   "time": "2022-05-12T10:16:49.450139391-07:00",
   "prefix": "interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]/ipv4/addresses/address[ip=127.0.0.1]",
   "updates": [
   {
   "Path": "state/ip",
   "values": {
   "state/ip": "127.0.0.1"
   }
   },
   {
   "Path": "state/prefix-length",
   "values": {
   "state/prefix-length": 32
   }
   },
   {
   "Path": "state/origin",
   "values": {
   "state/origin": "STATIC"
   }
   }
   ]
   }
   {
   "source": "10.92.196.149:50051",
   "subscription-name": "default-1652375806",
   "timestamp": 1652375809450262600,
   "time": "2022-05-12T10:16:49.4502626-07:00",
   "prefix": "interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]/ipv4/addresses/address[ip=127.0.0.64]",
   "updates": [
   {
   "Path": "state/ip",
   "values": {
   "state/ip": "127.0.0.64"
   }
   },
   {
   "Path": "state/prefix-length",
   "values": {
   "state/prefix-length": 32
   }
   },
   {
   "Path": "state/origin",
   "values": {
   "state/origin": "STATIC"
   }
   }
   ]
   }
   {
   "source": "10.92.196.149:50051",
   "subscription-name": "default-1652375806",
   "timestamp": 1652375809452684011,
   "time": "2022-05-12T10:16:49.452684011-07:00",
   "prefix": "interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]",
   "updates": [
   {
   "Path": "ipv4/state/enabled",
   "values": {
   "ipv4/state/enabled": true
   }
   },
   {
   "Path": "ipv4/state/mtu",
   "values": {
   "ipv4/state/mtu": 65535
   }
   }
   ]
   }
   {
   "source": "10.92.196.149:50051",
   "subscription-name": "default-1652375806",
   "timestamp": 1652375809452796022,
   "time": "2022-05-12T10:16:49.452796022-07:00",
   "prefix": "interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]/ipv6/addresses/address[ip=abcd::10:255:2:76]",
   "updates": [
   {
   "Path": "state/ip",
   "values": {
   "state/ip": "abcd::10:255:2:76"
   }
   },
   {
   "Path": "state/prefix-length",
   "values": {
   "state/prefix-length": 128
   }
   },
   {
   "Path": "state/origin",
   "values": {
   "state/origin": "STATIC"
   }
   },
   {
   "Path": "state/status",
   "values": {
   "state/status": "PREFERRED"
   }
   }
   ]
   }
   {
   "source": "10.92.196.149:50051",
   "subscription-name": "default-1652375806",
   "timestamp": 1652375809452936008,
   "time": "2022-05-12T10:16:49.452936008-07:00",
   "prefix": "interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]/ipv6/addresses/address[ip=fe80::2c5:2cf0:3:f03d]",
   "updates": [
   {
   "Path": "state/ip",
   "values": {
   "state/ip": "fe80::2c5:2cf0:3:f03d"
   }
   },
   {
   "Path": "state/prefix-length",
   "values": {
   "state/prefix-length": 128
   }
   },
   {
   "Path": "state/origin",
   "values": {
   "state/origin": "RANDOM"
   }
   },
   {
   "Path": "state/status",
   "values": {
   "state/status": "PREFERRED"
   }
   }
   ]
   }
   {
   "source": "10.92.196.149:50051",
   "subscription-name": "default-1652375806",
   "timestamp": 1652375809455088976,
   "time": "2022-05-12T10:16:49.455088976-07:00",
   "prefix": "interfaces/interface[name=lo0]/subinterfaces/subinterface[index=0]",
   "updates": [
   {
   "Path": "ipv6/state/enabled",
   "values": {
   "ipv6/state/enabled": true
   }
   },
   {
   "Path": "ipv6/state/mtu",
   "values": {
   "ipv6/state/mtu": 4294967295
   }
   }
   ]
   }

json.encoding.raw.txt
json.encoding.formatted.txt
proto.encoding.formatted.txt
proto.encoding.raw.txt

[karimra]

Hi, took me some time to dig into this but it looks like the whole message marshaling into json is failing because the value of state/prefix-length is not a valid json string.
Whatever gnmi server you are querying is returning a single space as a json value for state/prefix-length

update:  {
  timestamp:  1651733127911788946
  prefix:  {
    elem:  {
      name:  "interfaces"
    }
    elem:  {
      name:  "interface"
      key:  {
        key:  "name"
        value:  "lo0"
      }
    }
    elem:  {
      name:  "subinterfaces"
    }
    elem:  {
      name:  "subinterface"
      key:  {
        key:  "index"
        value:  "0"
      }
    }
    elem:  {
      name:  "ipv4"
    }
    elem:  {
      name:  "addresses"
    }
    elem:  {
      name:  "address"
      key:  {
        key:  "ip"
        value:  "128.220.11.66"
      }
    }
  }
  update:  {
    path:  {
      elem:  {
        name:  "state"
      }
      elem:  {
        name:  "ip"
      }
    }
    val:  {
      json_val:  "\"128.220.11.66\""
    }
  }
  update:  {
    path:  {
      elem:  {
        name:  "state"
      }
      elem:  {
        name:  "prefix-length"
      }
    }
    val:  {
      json_val:  " " <---- # This is the culprit
    }
  }
  update:  {
    path:  {
      elem:  {
        name:  "state"
      }
      elem:  {
        name:  "origin"
      }
    }
    val:  {
      json_val:  "\"STATIC\""
    }
  }
}