From 54f4a3a38b22787738187522f78cde1d687cab4f Mon Sep 17 00:00:00 2001
From: Sven Rebhan <36194019+srebhan@users.noreply.github.com>
Date: Mon, 28 Nov 2022 20:58:43 +0100
Subject: [PATCH] fix(inputs.gnmi): Do not provide empty prefix for
 subscription request. (#12275)

---
 plugins/inputs/gnmi/gnmi.go | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/plugins/inputs/gnmi/gnmi.go b/plugins/inputs/gnmi/gnmi.go
index 8d3303328..79f7367cb 100644
--- a/plugins/inputs/gnmi/gnmi.go
+++ b/plugins/inputs/gnmi/gnmi.go
@@ -255,6 +255,12 @@ func (c *GNMI) newSubscribeRequest() (*gnmiLib.SubscribeRequest, error) {
 		return nil, err
 	}
 
+	// Do not provide an empty prefix. Required for Huawei NE40 router v8.21
+	// (and possibly others). See https://github.com/influxdata/telegraf/issues/12273.
+	if gnmiPath.Origin == "" && gnmiPath.Target == "" && len(gnmiPath.Elem) == 0 {
+		gnmiPath = nil
+	}
+
 	if c.Encoding != "proto" && c.Encoding != "json" && c.Encoding != "json_ietf" && c.Encoding != "bytes" {
 		return nil, fmt.Errorf("unsupported encoding %s", c.Encoding)
 	}