feat(inputs.opcua): add use regular reads workaround (#11630)

plugins/inputs/opcua/README.md

@@ -95,6 +95,9 @@ Plugin minimum tested version: 1.16
   # [inputs.opcua.workarounds]
     ## Set additional valid status codes, StatusOK (0x0) is always considered valid
     # additional_valid_status_codes = ["0xC0"]
+
+    ## Use regular reads instead of registered reads
+    # use_regular_reads = false
 ```
 
 ## Node Configuration
@@ -152,6 +155,10 @@ This example group configuration has two groups with two nodes each:
   ]
 ```
 
+## Metrics
+
+Metrics are produced according to the defined node ID and group configuration.
+
 ## Example Output
 
 ```text

plugins/inputs/opcua/opcua.go

@@ -26,6 +26,7 @@ var sampleConfig string
 
 type OpcuaWorkarounds struct {
 	AdditionalValidStatusCodes []string `toml:"additional_valid_status_codes"`
+	UseRegularReads            bool     `toml:"use_regular_reads"`
 }
 
 // OpcUA type
@@ -365,17 +366,31 @@ func Connect(o *OpcUA) error {
 			return fmt.Errorf("error in Client Connection: %s", err)
 		}
 
-		regResp, err := o.client.RegisterNodes(&ua.RegisterNodesRequest{
-			NodesToRegister: o.nodeIDs,
-		})
-		if err != nil {
-			return fmt.Errorf("registerNodes failed: %v", err)
-		}
+		if !o.Workarounds.UseRegularReads {
+			regResp, err := o.client.RegisterNodes(&ua.RegisterNodesRequest{
+				NodesToRegister: o.nodeIDs,
+			})
+			if err != nil {
+				return fmt.Errorf("registerNodes failed: %v", err)
+			}
 
-		o.req = &ua.ReadRequest{
-			MaxAge:             2000,
-			NodesToRead:        readvalues(regResp.RegisteredNodeIDs),
-			TimestampsToReturn: ua.TimestampsToReturnBoth,
+			o.req = &ua.ReadRequest{
+				MaxAge:             2000,
+				TimestampsToReturn: ua.TimestampsToReturnBoth,
+				NodesToRead:        readvalues(regResp.RegisteredNodeIDs),
+			}
+		} else {
+			var nodesToRead []*ua.ReadValueID
+
+			for _, nid := range o.nodeIDs {
+				nodesToRead = append(nodesToRead, &ua.ReadValueID{NodeID: nid})
+			}
+
+			o.req = &ua.ReadRequest{
+				MaxAge:             2000,
+				TimestampsToReturn: ua.TimestampsToReturnBoth,
+				NodesToRead:        nodesToRead,
+			}
 		}
 
 		err = o.getData()
@@ -438,7 +453,7 @@ func (o *OpcUA) getData() error {
 	resp, err := o.client.Read(o.req)
 	if err != nil {
 		o.ReadError.Incr(1)
-		return fmt.Errorf("RegisterNodes Read failed: %v", err)
+		return fmt.Errorf("Read failed: %w", err)
 	}
 	o.ReadSuccess.Incr(1)
 	for i, d := range resp.Results {

plugins/inputs/opcua/opcua_test.go

@@ -136,6 +136,31 @@ func TestClient1Integration(t *testing.T) {
 			t.Errorf("Tag: %s has value: %v", o.nodes[i].tag.FieldName, v.Value)
 		}
 	}
+
+	// test regular reads workaround
+	o.Workarounds.UseRegularReads = true
+
+	for i := range o.nodeData {
+		o.nodeData[i] = OPCData{}
+	}
+
+	err = Connect(&o)
+	if err != nil {
+		t.Fatalf("Connect Error: %s", err)
+	}
+
+	for i, v := range o.nodeData {
+		if v.Value != nil {
+			types := reflect.TypeOf(v.Value)
+			value := reflect.ValueOf(v.Value)
+			compare := fmt.Sprintf("%v", value.Interface())
+			if compare != testopctags[i].Want {
+				t.Errorf("Tag %s: Values %v for type %s  does not match record", o.nodes[i].tag.FieldName, value.Interface(), types)
+			}
+		} else if testopctags[i].Want != nil {
+			t.Errorf("Tag: %s has value: %v", o.nodes[i].tag.FieldName, v.Value)
+		}
+	}
 }
 
 func MapOPCTag(tags OPCTags) (out NodeSettings) {

plugins/inputs/opcua/sample.conf

@@ -85,3 +85,6 @@
   # [inputs.opcua.workarounds]
     ## Set additional valid status codes, StatusOK (0x0) is always considered valid
     # additional_valid_status_codes = ["0xC0"]
+
+    ## Use regular reads instead of registered reads
+    # use_regular_reads = false