feat(inputs.gnmi): Allow canonical field names (#13326)

plugins/inputs/gnmi/README.md

@@ -52,6 +52,9 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
   ## gRPC Maximum Message Size
   # max_msg_size = "4MB"
 
+  ## Enable to get the canonical path as field-name
+  # canonical_field_names = false
+
   ## enable client-side TLS and define CA to authenticate the device
   # enable_tls = false
   # tls_ca = "/etc/telegraf/ca.pem"

plugins/inputs/gnmi/gnmi.go

@@ -57,6 +57,7 @@ type GNMI struct {
 	Redial              config.Duration   `toml:"redial"`
 	MaxMsgSize          config.Size       `toml:"max_msg_size"`
 	Trace               bool              `toml:"dump_responses"`
+	CanonicalFieldNames bool              `toml:"canonical_field_names"`
 	EnableTLS           bool              `toml:"enable_tls"`
 	Log                 telegraf.Logger   `toml:"-"`
 	internaltls.ClientConfig
@@ -192,15 +193,18 @@ func (c *GNMI) Start(acc telegraf.Accumulator) error {
 	for _, addr := range c.Addresses {
 		go func(addr string) {
 			defer c.wg.Done()
-			confHandler := configHandler{
+
+			h := handler{
+				address:             addr,
 				aliases:             c.internalAliases,
-				subscriptions: c.TagSubscriptions,
+				tagsubs:             c.TagSubscriptions,
-				maxSize:       int(c.MaxMsgSize),
+				maxMsgSize:          int(c.MaxMsgSize),
-				log:           c.Log,
-				trace:         c.Trace,
 				vendorExt:           c.VendorSpecific,
+				tagStore:            newTagStore(c.TagSubscriptions),
+				trace:               c.Trace,
+				canonicalFieldNames: c.CanonicalFieldNames,
+				log:                 c.Log,
 			}
-			h := newHandler(addr, confHandler)
 			for ctx.Err() == nil {
 				if err := h.subscribeGNMI(ctx, acc, tlscfg, request); err != nil && ctx.Err() == nil {
 					acc.AddError(err)

plugins/inputs/gnmi/handler.go

@@ -36,32 +36,10 @@ type handler struct {
 	vendorExt           []string
 	tagStore            *tagStore
 	trace               bool
+	canonicalFieldNames bool
 	log                 telegraf.Logger
 }
 
-// Allow to convey additionnal configuration elements
-type configHandler struct {
-	aliases       map[string]string
-	subscriptions []TagSubscription
-	maxSize       int
-	log           telegraf.Logger
-	trace         bool
-	vendorExt     []string
-}
-
-func newHandler(addr string, confHandler configHandler) *handler {
-	return &handler{
-		address:    addr,
-		aliases:    confHandler.aliases,
-		tagsubs:    confHandler.subscriptions,
-		maxMsgSize: confHandler.maxSize,
-		vendorExt:  confHandler.vendorExt,
-		tagStore:   newTagStore(confHandler.subscriptions),
-		trace:      confHandler.trace,
-		log:        confHandler.log,
-	}
-}
-
 // SubscribeGNMI and extract telemetry data
 func (h *handler) subscribeGNMI(ctx context.Context, acc telegraf.Accumulator, tlscfg *tls.Config, request *gnmiLib.SubscribeRequest) error {
 	var creds credentials.TransportCredentials
@@ -266,6 +244,12 @@ func (h *handler) handleSubscribeResponseUpdate(acc telegraf.Accumulator, respon
 				// conversion on the key.
 				key = key[len(aliasPath)+1:]
 			} else if len(aliasPath) >= len(key) {
+				if h.canonicalFieldNames {
+					// Strip the origin is any for the field names
+					if parts := strings.SplitN(key, ":", 2); len(parts) == 2 {
+						key = parts[1]
+					}
+				} else {
 					// Otherwise use the last path element as the field key.
 					key = path.Base(key)
 
@@ -277,6 +261,7 @@ func (h *handler) handleSubscribeResponseUpdate(acc telegraf.Accumulator, respon
 						continue
 					}
 				}
+			}
 			grouper.Add(name, tags, timestamp, key, v)
 		}
 	}

plugins/inputs/gnmi/sample.conf

@@ -16,6 +16,9 @@
   ## gRPC Maximum Message Size
   # max_msg_size = "4MB"
 
+  ## Enable to get the canonical path as field-name
+  # canonical_field_names = false
+
   ## enable client-side TLS and define CA to authenticate the device
   # enable_tls = false
   # tls_ca = "/etc/telegraf/ca.pem"

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

@@ -0,0 +1 @@
+interfaces,name=eth42,path=openconfig-interfaces:/interfaces/interface,source=127.0.0.1 /interfaces/interface/descr="eth42",/interfaces/interface/config/id=42425u,/interfaces/interface/state/in_pkts=5678u,/interfaces/interface/state/out_pkts=5125u 1673608605875353770

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

@@ -0,0 +1,79 @@
+[
+    {
+        "update": {
+            "timestamp": "1673608605875353770",
+            "prefix": {
+                "origin": "openconfig-interfaces",
+                "elem": [
+                    {
+                        "name": "interfaces"
+                    },
+                    {
+                        "name": "interface",
+                        "key":{"name":"eth42"}
+                    }
+                ],
+                "target": "subscription"
+            },
+            "update": [
+                {
+                    "path": {
+                        "elem": [
+                            {
+                                "name": "descr"
+                            }
+                        ]
+                    },
+                    "val": {
+                        "stringVal": "eth42"
+                    }
+                },
+                {
+                    "path": {
+                        "elem": [
+                            {
+                                "name": "config"
+                            },
+                            {
+                                "name": "id"
+                            }
+                        ]
+                    },
+                    "val": {
+                        "uintVal": "42425"
+                    }
+                },
+                {
+                    "path": {
+                        "elem": [
+                            {
+                                "name": "state"
+                            },
+                            {
+                                "name": "in-pkts"
+                            }
+                        ]
+                    },
+                    "val": {
+                        "uintVal": "5678"
+                    }
+                },
+                {
+                    "path": {
+                        "elem": [
+                            {
+                                "name": "state"
+                            },
+                            {
+                                "name": "out-pkts"
+                            }
+                        ]
+                    },
+                    "val": {
+                        "uintVal": "5125"
+                    }
+                }
+            ]
+        }
+    }
+]

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

@@ -0,0 +1,29 @@
+[[inputs.gnmi]]
+  addresses     = ["dummy"]
+  name_override = "gnmi"
+  redial        = "10s"
+  canonical_field_names = true
+  [[inputs.gnmi.subscription]]
+    name              = "interfaces"
+    origin            = "openconfig-interfaces"
+    path              = "/interfaces/interface/descr"
+    subscription_mode = "sample"
+    sample_interval   = "10s"
+  [[inputs.gnmi.subscription]]
+    name              = "interfaces"
+    origin            = "openconfig-interfaces"
+    path              = "/interfaces/interface/config/id"
+    subscription_mode = "sample"
+    sample_interval   = "10s"
+  [[inputs.gnmi.subscription]]
+    name              = "interfaces"
+    origin            = "openconfig-interfaces"
+    path              = "/interfaces/interface/state/in-pkts"
+    subscription_mode = "sample"
+    sample_interval   = "10s"
+  [[inputs.gnmi.subscription]]
+    name              = "interfaces"
+    origin            = "openconfig-interfaces"
+    path              = "/interfaces/interface/state/out-pkts"
+    subscription_mode = "sample"
+    sample_interval   = "10s"