feat(agent): Add structured_log_add_input_tags. Adds the input tags into the logger JSON output.

config/config.go

@@ -252,6 +252,10 @@ type AgentConfig struct {
 	// Ignored if "logformat" is not "structured".
 	StructuredLogMessageKey string `toml:"structured_log_message_key"`
 
+	// When set to true and using logformat = "structured", the tags of each
+	// input plugin are added to the log output as a "tags" JSON field.
+	StructuredLogAddInputTags bool `toml:"structured_log_add_input_tags"`
+
 	// The file will be rotated after the time interval specified.  When set
 	// to 0 no time based rotation is performed.
 	LogfileRotationInterval Duration `toml:"logfile_rotation_interval"`
@@ -570,6 +574,19 @@ func (c *Config) LoadAll(configFiles ...string) error {
 		}
 	}
 
+	// When loading multiple config files (e.g. via --config-directory), the
+	// [agent] section may be parsed after some input files, meaning
+	// buildInput saw StructuredLogAddInputTags=false and skipped the logger
+	// attribute. Therefore, it needs to be parsed again after loading all configs.
+	if c.Agent.StructuredLogAddInputTags {
+		for _, input := range c.Inputs {
+			if !input.Config.AddTagsToStructuredLogs && len(input.Config.Tags) > 0 {
+				input.Config.AddTagsToStructuredLogs = true
+				input.Log().AddAttribute("tags", input.Config.Tags)
+			}
+		}
+	}
+
 	// Sort the processors according to their `order` setting while
 	// using a stable sort to keep the file loading / file position order.
 	sort.Stable(c.Processors)
@@ -1690,6 +1707,7 @@ func (c *Config) buildInput(name, source string, tbl *ast.Table) (*models.InputC
 		Source:                  source,
 		AlwaysIncludeLocalTags:  c.Agent.AlwaysIncludeLocalTags,
 		AlwaysIncludeGlobalTags: c.Agent.AlwaysIncludeGlobalTags,
+		AddTagsToStructuredLogs: c.Agent.StructuredLogAddInputTags,
 	}
 	cp.Interval, _ = c.getFieldDuration(tbl, "interval")
 	cp.Precision, _ = c.getFieldDuration(tbl, "precision")

docs/CONFIGURATION.md

@@ -311,6 +311,28 @@ The agent table configures Telegraf and the defaults used across all plugins.
   Message key for structured logs, to override the default of "msg".
   Ignored if `logformat` is not "structured".
 
+- **structured_log_add_input_tags**:
+  To add input configuration tags to the log output.  
+  Example:
+
+    ```json
+      {
+        "time":"2026-03-27T09:14:36.078389805Z",
+        "level":"INFO",
+        "msg":"Error connecting to target. Restarting in 10s...",
+        "category":"inputs",
+        "plugin":"execd",
+        "tags":{
+          "server_host":"10.0.1.20",
+          "friendly_name":"friendly_server_name",
+          "log_source":"telegraf",
+          "metric_type":"logs"
+        }
+      }
+    ```
+
+  Ignored if `logformat` is not "structured".
+
 - **logfile**:
   Name of the file to be logged to or stderr if unset or empty. This
   setting is ignored for the "eventlog" format.

models/running_input.go

@@ -54,6 +54,9 @@ func NewRunningInput(input telegraf.Input, config *InputConfig) *RunningInput {
 	if err := logger.SetLogLevel(config.LogLevel); err != nil {
 		logger.Error(err)
 	}
+	if config.AddTagsToStructuredLogs && len(config.Tags) > 0 {
+		logger.AddAttribute("tags", config.Tags)
+	}
 	SetLoggerOnPlugin(input, logger)
 	SetStatisticsOnPlugin(input, logger, tags)
 
@@ -110,6 +113,10 @@ type InputConfig struct {
 	Filter                  Filter
 	AlwaysIncludeLocalTags  bool
 	AlwaysIncludeGlobalTags bool
+
+	// When true and using logformat = "structured", the input's tags are
+	// added to the log output as a "tags" JSON field.
+	AddTagsToStructuredLogs bool
 }
 
 func (*RunningInput) metricFiltered(metric telegraf.Metric) {