From 51dcf8dfd4b9be926fd45b584908e820df4c2b7a Mon Sep 17 00:00:00 2001
From: Jorge Hermo <jorgehermogonzalez@gmail.com>
Date: Sun, 6 Oct 2024 03:32:05 +0200
Subject: [PATCH] fix(transforms): optional metric namespace in `log_to_metric`
 transform (#21429)

* fix(transforms): optional namespace in log_to_metric transform

* docs: add changelog entry

* Update changelog.d/21423-optional-namespace-log-to-metric.fix.md

---------

Co-authored-by: Jesse Szwedko <jesse@szwedko.me>
---
 ...23-optional-namespace-log-to-metric.fix.md |  4 ++
 src/transforms/log_to_metric.rs               | 63 ++++++++++++++++---
 2 files changed, 60 insertions(+), 7 deletions(-)
 create mode 100644 changelog.d/21423-optional-namespace-log-to-metric.fix.md

diff --git a/changelog.d/21423-optional-namespace-log-to-metric.fix.md b/changelog.d/21423-optional-namespace-log-to-metric.fix.md
new file mode 100644
index 0000000000000..ba3e5e8df078d
--- /dev/null
+++ b/changelog.d/21423-optional-namespace-log-to-metric.fix.md
@@ -0,0 +1,4 @@
+When using the `all_metrics: true` flag in `log_to_metric` transform, the `namespace` field is now optional and no longer required. If the `namespace` field is not provided,
+the produced metric will not have a namespace at all.
+
+authors: jorgehermo9
diff --git a/src/transforms/log_to_metric.rs b/src/transforms/log_to_metric.rs
index 55af676814870..3136c99a7ec79 100644
--- a/src/transforms/log_to_metric.rs
+++ b/src/transforms/log_to_metric.rs
@@ -795,12 +795,15 @@ fn to_metrics(event: &Event) -> Result<Metric, TransformError> {
 
     let value = value.ok_or(TransformError::MetricDetailsNotFound)?;
 
-    Ok(
-        Metric::new_with_metadata(name, kind, value, log.metadata().clone())
-            .with_namespace(try_get_string_from_log(log, "namespace")?)
-            .with_tags(tags_result)
-            .with_timestamp(timestamp),
-    )
+    let mut metric = Metric::new_with_metadata(name, kind, value, log.metadata().clone())
+        .with_tags(tags_result)
+        .with_timestamp(timestamp);
+
+    if let Ok(namespace) = try_get_string_from_log(log, "namespace") {
+        metric = metric.with_namespace(namespace);
+    }
+
+    Ok(metric)
 }
 
 impl FunctionTransform for LogToMetric {
@@ -1608,11 +1611,19 @@ mod tests {
     }
 
     //  Metric Metadata Tests
+    //
     fn create_log_event(json_str: &str) -> Event {
+        create_log_event_with_namespace(json_str, Some("test_namespace"))
+    }
+
+    fn create_log_event_with_namespace(json_str: &str, namespace: Option<&str>) -> Event {
         let mut log_value: Value =
             serde_json::from_str(json_str).expect("JSON was not well-formatted");
         log_value.insert("timestamp", ts());
-        log_value.insert("namespace", "test_namespace");
+
+        if let Some(namespace) = namespace {
+            log_value.insert("namespace", namespace);
+        }
 
         let mut metadata = EventMetadata::default();
         metadata.set_source_id(Arc::new(ComponentKey::from("in")));
@@ -2003,4 +2014,42 @@ mod tests {
             .with_timestamp(Some(ts()))
         );
     }
+
+    #[tokio::test]
+    async fn transform_all_metrics_optional_namespace() {
+        let config = parse_yaml_config(
+            r#"
+            metrics: []
+            all_metrics: true
+            "#,
+        );
+
+        let json_str = r#"{
+          "counter": {
+            "value": 10.0
+          },
+          "kind": "incremental",
+          "name": "test.transform.counter",
+          "tags": {
+            "env": "test_env",
+            "host": "localhost"
+          }
+        }"#;
+        let log = create_log_event_with_namespace(json_str, None);
+        let metric = do_transform(config, log.clone()).await.unwrap();
+        assert_eq!(
+            *metric.as_metric(),
+            Metric::new_with_metadata(
+                "test.transform.counter",
+                MetricKind::Incremental,
+                MetricValue::Counter { value: 10.0 },
+                metric.metadata().clone(),
+            )
+            .with_tags(Some(metric_tags!(
+                "env" => "test_env",
+                "host" => "localhost",
+            )))
+            .with_timestamp(Some(ts()))
+        );
+    }
 }