fix(inputs.gnmi): Allow optional origin for update path (#13304)

plugins/inputs/gnmi/gnmi.go

@@ -346,34 +346,25 @@ func (s *Subscription) buildFullPath(c *GNMI) error {
 }
 
 func (s *Subscription) buildAlias(aliases map[string]string) error {
-	var err error
-	var gnmiLongPath, gnmiShortPath *gnmiLib.Path
-
 	// Build the subscription path without keys
-	if gnmiLongPath, err = parsePath(s.Origin, s.Path, ""); err != nil {
+	gnmiPath, err := parsePath(s.Origin, s.Path, "")
-		return err
+	if err != nil {
-	}
-	if gnmiShortPath, err = parsePath("", s.Path, ""); err != nil {
 		return err
 	}
 
-	longPath, _, err := handlePath(gnmiLongPath, nil, nil, "")
+	origin, spath, _, err := handlePath(gnmiPath, nil, nil, "")
 	if err != nil {
-		return fmt.Errorf("handling long-path failed: %w", err)
+		return fmt.Errorf("handling path failed: %w", err)
-	}
-	shortPath, _, err := handlePath(gnmiShortPath, nil, nil, "")
-	if err != nil {
-		return fmt.Errorf("handling short-path failed: %w", err)
 	}
 
 	// If the user didn't provide a measurement name, use last path element
 	name := s.Name
-	if len(name) == 0 {
+	if name == "" {
-		name = path.Base(shortPath)
+		name = path.Base(spath)
 	}
-	if len(name) > 0 {
+	if name != "" {
-		aliases[longPath] = name
+		aliases[origin+spath] = name
-		aliases[shortPath] = name
+		aliases[spath] = name
 	}
 	return nil
 }

plugins/inputs/gnmi/handler.go

@@ -174,10 +174,12 @@ func (h *handler) handleSubscribeResponseUpdate(acc telegraf.Accumulator, respon
 	}
 
 	if response.Update.Prefix != nil {
+		var origin string
 		var err error
-		if prefix, prefixAliasPath, err = handlePath(response.Update.Prefix, prefixTags, h.aliases, ""); err != nil {
+		if origin, prefix, prefixAliasPath, err = handlePath(response.Update.Prefix, prefixTags, h.aliases, ""); err != nil {
 			h.log.Errorf("handling path %q failed: %v", response.Update.Prefix, err)
 		}
+		prefix = origin + prefix
 	}
 
 	prefixTags["source"], _, _ = net.SplitHostPort(h.address)
@@ -287,7 +289,7 @@ func (h *handler) handleSubscribeResponseUpdate(acc telegraf.Accumulator, respon
 
 // HandleTelemetryField and add it to a measurement
 func (h *handler) handleTelemetryField(update *gnmiLib.Update, tags map[string]string, prefix string) (string, map[string]interface{}) {
-	gpath, aliasPath, err := handlePath(update.Path, tags, h.aliases, prefix)
+	_, gpath, aliasPath, err := handlePath(update.Path, tags, h.aliases, prefix)
 	if err != nil {
 		h.log.Errorf("handling path %q failed: %v", update.Path, err)
 	}

plugins/inputs/gnmi/testcases/issue_12931/expected.out

@@ -0,0 +1 @@
+interface,name=ethernet-1/1,source=127.0.0.1 interface=1i,transceiver=2i,ethernet=3i,ethernet/flow_control="false",sflow="disable" 1679648530391910312

plugins/inputs/gnmi/testcases/issue_12931/responses.json

@@ -0,0 +1,94 @@
+[
+    {
+        "update": {
+            "timestamp": "1679648530391910312",
+            "update": [
+                {
+                    "path": {
+                        "origin": "srl_nokia-interfaces",
+                        "elem": [
+                            {
+                                "name": "interface",
+                                "key":{"name":"ethernet-1/1"}
+                            }
+                        ]
+                    },
+                    "val": {
+                        "intVal": "1"
+                    }
+                },
+                {
+                    "path": {
+                        "origin": "srl_nokia-interfaces",
+                        "elem": [
+                            {
+                                "name": "interface",
+                                "key":{"name":"ethernet-1/1"}
+                            },
+                            {
+                                "name": "transceiver"
+                            }
+                        ]
+                    },
+                    "val": {
+                        "intVal": "2"
+                    }
+                },
+                {
+                    "path": {
+                        "origin": "srl_nokia-interfaces",
+                        "elem": [
+                            {
+                                "name": "interface",
+                                "key":{"name":"ethernet-1/1"}
+                            },
+                            {
+                                "name": "ethernet"
+                            }
+                        ]
+                    },
+                    "val": {
+                        "intVal": "3"
+                    }
+                },
+                {
+                    "path": {
+                        "origin": "srl_nokia-interfaces",
+                        "elem": [
+                            {
+                                "name": "interface",
+                                "key":{"name":"ethernet-1/1"}
+                            },
+                            {
+                                "name": "ethernet"
+                            },
+                            {
+                                "name": "flow-control"
+                            }
+                        ]
+                    },
+                    "val": {
+                        "stringVal": "false"
+                    }
+                },
+                {
+                    "path": {
+                        "origin": "srl_nokia-interfaces",
+                        "elem": [
+                            {
+                                "name": "interface",
+                                "key":{"name":"ethernet-1/1"}
+                            },
+                            {
+                                "name": "sflow"
+                            }
+                        ]
+                    },
+                    "val": {
+                        "stringVal": "disable"
+                    }
+                }
+           ]
+        }
+    }
+]

plugins/inputs/gnmi/testcases/issue_12931/telegraf.conf

@@ -0,0 +1,10 @@
+[[inputs.gnmi]]
+  addresses     = ["dummy"]
+  name_override = "gnmi"
+  redial        = "10s"
+
+  [[inputs.gnmi.subscription]]
+    name = "interface"
+    path = "/interface"
+    subscription_mode = "sample"
+    sample_interval = "10s"

plugins/inputs/gnmi/utils.go

@@ -13,7 +13,9 @@ import (
 )
 
 // Parse path to path-buffer and tag-field
-func handlePath(gnmiPath *gnmiLib.Path, tags map[string]string, aliases map[string]string, prefix string) (pathBuffer string, aliasPath string, err error) {
+//
+//nolint:revive //function-result-limit conditionally 4 return results allowed
+func handlePath(gnmiPath *gnmiLib.Path, tags map[string]string, aliases map[string]string, prefix string) (origin, path, alias string, err error) {
 	builder := bytes.NewBufferString(prefix)
 
 	// Some devices do report the origin in the first path element
@@ -28,28 +30,25 @@ func handlePath(gnmiPath *gnmiLib.Path, tags map[string]string, aliases map[stri
 
 	// Prefix with origin
 	if len(gnmiPath.Origin) > 0 {
-		if _, err := builder.WriteString(gnmiPath.Origin); err != nil {
+		origin = gnmiPath.Origin + ":"
-			return "", "", err
-		}
-		if _, err := builder.WriteRune(':'); err != nil {
-			return "", "", err
-		}
 	}
 
 	// Parse generic keys from prefix
 	for _, elem := range gnmiPath.Elem {
 		if len(elem.Name) > 0 {
 			if _, err := builder.WriteRune('/'); err != nil {
-				return "", "", err
+				return "", "", "", err
 			}
 			if _, err := builder.WriteString(elem.Name); err != nil {
-				return "", "", err
+				return "", "", "", err
 			}
 		}
 		name := builder.String()
 
-		if _, exists := aliases[name]; exists {
+		if _, exists := aliases[origin+name]; exists {
-			aliasPath = name
+			alias = origin + name
+		} else if _, exists := aliases[name]; exists {
+			alias = name
 		}
 
 		if tags != nil {
@@ -66,7 +65,7 @@ func handlePath(gnmiPath *gnmiLib.Path, tags map[string]string, aliases map[stri
 		}
 	}
 
-	return builder.String(), aliasPath, nil
+	return origin, builder.String(), alias, nil
 }
 
 // equalPathNoKeys checks if two gNMI paths are equal, without keys