add gauge

Author: cijothomas

opentelemetry-otlp/tests/integration_test/expected/metrics/test_gauge_meter.json

@@ -0,0 +1,46 @@
+{
+  "resourceMetrics": [
+    {
+      "resource": {
+        "attributes": [
+          {
+            "key": "service.name",
+            "value": {
+              "stringValue": "metrics-integration-test"
+            }
+          }
+        ]
+      },
+      "scopeMetrics": [
+        {
+          "scope": {
+            "name": "test_gauge_meter"
+          },
+          "metrics": [
+            {
+              "name": "example_gauge",
+              "sum": {
+                "dataPoints": [
+                  {
+                    "attributes": [
+                      {
+                        "key": "mykey5",
+                        "value": {
+                          "stringValue": "myvalue5"
+                        }
+                      }
+                    ],
+                    "startTimeUnixNano": "1734259947902844000",
+                    "timeUnixNano": "1734259952816822000",
+                    "asDouble": "-1.10"
+                  }
+                ],
+                "aggregationTemporality": 2
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

opentelemetry-otlp/tests/integration_test/tests/metrics.rs

@@ -1,3 +1,10 @@
+//! OTLP integration tests for metrics. These tests cover various OTel Metric
+//! SDK/OTLP Exporter scenarios in particular focusing on ensuring that various
+//! async runtimes works well. This also includes validating that shutdown,
+//! force_flush are working as expected. Validation is simple in the sense it
+//! merely checks the presence of a UUID in the exported metrics, which is good
+//! enough to confirm that metrics have been accepted by OTel Collector.
+//!
 #![cfg(unix)]
 
 use anyhow::{Ok, Result};

opentelemetry-otlp/tests/integration_test/tests/metrics_roundtrip.rs

@@ -1,4 +1,7 @@
-//! OTLP integration tests for metrics
+//! OTLP integration tests for metrics. These tests cover the breadth of Metric
+//! API by testing all instrument types and ensuring that the data is correctly
+//! exported to the collector by validating the exported data against the
+//! expected results.
 //! Note: these are all expressed using Serde types for the deserialized metrics records.
 //! We might consider changing this once we have fixed the issue identified in the #[ignore]d test
 //! `test_roundtrip_example_data` - as the roundtripping is currently broken for metrics.
@@ -106,6 +109,24 @@ mod metrictests_roundtrip {
 
         Ok(())
     }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+    async fn test_gauge() -> Result<()> {
+        let meter_provider = metric_helpers::setup_metrics_tokio().await;
+        const METER_NAME: &str = "test_gauge_meter";
+
+        // Add data to up_down_counter
+        let meter = opentelemetry::global::meter_provider().meter(METER_NAME);
+        let gauge = meter.f64_gauge("example_gauge").build();
+        gauge.record(-1.10, &[KeyValue::new("mykey5", "myvalue5")]);
+
+        meter_provider.shutdown()?;
+        tokio::time::sleep(SLEEP_DURATION).await;
+
+        validate_metrics_against_results(METER_NAME)?;
+
+        Ok(())
+    }
 }
 
 ///