From 424283f13805fb7bd848e98503d0d5f0d472a632 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <36194019+srebhan@users.noreply.github.com>
Date: Mon, 7 Aug 2023 22:48:47 +0200
Subject: [PATCH] fix(inputs.opcua): Register node IDs again on reconnect
 (#13682)

---
 plugins/common/opcua/input/input_client.go       | 11 ++++-------
 plugins/inputs/opcua/read_client.go              | 16 ++++++++++------
 .../inputs/opcua_listener/subscribe_client.go    |  5 +++++
 3 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/plugins/common/opcua/input/input_client.go b/plugins/common/opcua/input/input_client.go
index 6b2e00753..31501c6c0 100644
--- a/plugins/common/opcua/input/input_client.go
+++ b/plugins/common/opcua/input/input_client.go
@@ -79,8 +79,7 @@ func (o *InputClientConfig) Validate() error {
 }
 
 func (o *InputClientConfig) CreateInputClient(log telegraf.Logger) (*OpcUAInputClient, error) {
-	err := o.Validate()
-	if err != nil {
+	if err := o.Validate(); err != nil {
 		return nil, err
 	}
 
@@ -97,15 +96,13 @@ func (o *InputClientConfig) CreateInputClient(log telegraf.Logger) (*OpcUAInputC
 	}
 
 	log.Debug("Initialising node to metric mapping")
-	err = c.InitNodeMetricMapping()
-	if err != nil {
+	if err := c.InitNodeMetricMapping(); err != nil {
 		return nil, err
 	}
 
 	c.initLastReceivedValues()
 
-	err = c.initNodeIDs()
-	return c, err
+	return c, nil
 }
 
 // NodeMetricMapping mapping from a single node to a metric
@@ -327,7 +324,7 @@ func (o *OpcUAInputClient) InitNodeMetricMapping() error {
 	return nil
 }
 
-func (o *OpcUAInputClient) initNodeIDs() error {
+func (o *OpcUAInputClient) InitNodeIDs() error {
 	o.NodeIDs = make([]*ua.NodeID, 0, len(o.NodeMetricMapping))
 	for _, node := range o.NodeMetricMapping {
 		nid, err := ua.ParseNodeID(node.Tag.NodeID())
diff --git a/plugins/inputs/opcua/read_client.go b/plugins/inputs/opcua/read_client.go
index 4bbb566c3..29986e218 100644
--- a/plugins/inputs/opcua/read_client.go
+++ b/plugins/inputs/opcua/read_client.go
@@ -52,9 +52,14 @@ func (rc *ReadClientConfig) CreateReadClient(log telegraf.Logger) (*ReadClient,
 }
 
 func (o *ReadClient) Connect() error {
-	err := o.OpcUAClient.Connect()
-	if err != nil {
-		return err
+	if err := o.OpcUAClient.Connect(); err != nil {
+		return fmt.Errorf("connect failed: %w", err)
+	}
+
+	// Make sure we setup the node-ids correctly after reconnect
+	// as the server might be restarted and IDs changed
+	if err := o.OpcUAInputClient.InitNodeIDs(); err != nil {
+		return fmt.Errorf("initializing node IDs failed: %w", err)
 	}
 
 	readValueIds := make([]*ua.ReadValueID, 0, len(o.NodeIDs))
@@ -67,7 +72,7 @@ func (o *ReadClient) Connect() error {
 			NodesToRegister: o.NodeIDs,
 		})
 		if err != nil {
-			return fmt.Errorf("registerNodes failed: %w", err)
+			return fmt.Errorf("registering nodes failed: %w", err)
 		}
 
 		for _, v := range regResp.RegisteredNodeIDs {
@@ -81,8 +86,7 @@ func (o *ReadClient) Connect() error {
 		NodesToRead:        readValueIds,
 	}
 
-	err = o.read()
-	if err != nil {
+	if err := o.read(); err != nil {
 		return fmt.Errorf("get data failed: %w", err)
 	}
 
diff --git a/plugins/inputs/opcua_listener/subscribe_client.go b/plugins/inputs/opcua_listener/subscribe_client.go
index a327b7f13..a42738df2 100644
--- a/plugins/inputs/opcua_listener/subscribe_client.go
+++ b/plugins/inputs/opcua_listener/subscribe_client.go
@@ -37,6 +37,11 @@ func (sc *SubscribeClientConfig) CreateSubscribeClient(log telegraf.Logger) (*Su
 	if err != nil {
 		return nil, err
 	}
+
+	if err := client.InitNodeIDs(); err != nil {
+		return nil, err
+	}
+
 	subClient := &SubscribeClient{
 		OpcUAInputClient:   client,
 		Config:             *sc,