feat: adds createdTimestamp to counters exposed via prometheus protouf protocol (#1532)

#1498

Signed-off-by: cmaune <[email protected]>
Co-authored-by: cmaune <[email protected]>

Author: cmaune

integration-tests/it-exporter/it-exporter-test/src/test/java/io/prometheus/metrics/it/exporter/test/ExporterIT.java

@@ -10,6 +10,7 @@
 import java.net.URISyntaxException;
 import java.net.URLEncoder;
 import java.util.List;
+import java.util.regex.Pattern;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
@@ -101,11 +102,22 @@ public void testPrometheusProtobufDebugFormat(String format, String expected) th
     assertThat(response.status).isEqualTo(200);
     assertContentType(
         "text/plain;charset=utf-8", response.getHeader("Content-Type").replace(" ", ""));
-    assertThat(response.stringBody().trim())
-        .isEqualTo(
-            Resources.toString(Resources.getResource(expected), UTF_8)
-                .trim()
-                .replace("<app>", sampleApp));
+
+    String actualResponse = response.stringBody().trim();
+    String expectedResponse =
+        Resources.toString(Resources.getResource(expected), UTF_8)
+            .trim()
+            .replace("<app>", sampleApp);
+
+    if ("prometheus-protobuf".equals(format)) {
+      assertThat(actualResponse)
+          .matches(
+              Pattern.quote(expectedResponse)
+                  .replace("<CREATED_TIMESTAMP_SECONDS>", "\\E\\d+\\Q")
+                  .replace("<CREATED_TIMESTAMP_NANOS>", "\\E\\d+\\Q"));
+    } else {
+      assertThat(actualResponse).isEqualTo(expectedResponse);
+    }
   }
 
   @Test

integration-tests/it-exporter/it-exporter-test/src/test/resources/debug-protobuf.txt

@@ -37,6 +37,10 @@ type: COUNTER
 metric {
   counter {
     value: 17.0
+    created_timestamp {
+      seconds: <CREATED_TIMESTAMP_SECONDS>
+      nanos: <CREATED_TIMESTAMP_NANOS>
+    }
   }
 }
 

prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/CounterTest.java

@@ -120,8 +120,8 @@ public void testTotalStrippedFromName(String name) {
     Metrics.MetricFamily protobufData =
         new PrometheusProtobufWriterImpl().convert(counter.collect(), EscapingScheme.ALLOW_UTF8);
     assertThat(ProtobufUtil.shortDebugString(protobufData))
-        .isEqualTo(
-            "name: \"my_counter_seconds_total\" type: COUNTER metric { counter { value: 0.0 } }");
+        .matches(
+            "^name: \"my_counter_seconds_total\" type: COUNTER metric \\{ counter \\{ value: 0.0 created_timestamp \\{ seconds: \\d+ nanos: \\d+ } } }$");
   }
 
   @Test

prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/internal/PrometheusProtobufWriterImpl.java

@@ -130,6 +130,10 @@ private Metrics.Metric.Builder convert(CounterDataPointSnapshot data, EscapingSc
     if (data.getExemplar() != null) {
       counterBuilder.setExemplar(convert(data.getExemplar(), scheme));
     }
+    if (data.hasCreatedTimestamp()) {
+      counterBuilder.setCreatedTimestamp(
+          ProtobufUtil.timestampFromMillis(data.getCreatedTimestampMillis()));
+    }
     Metrics.Metric.Builder metricBuilder = Metrics.Metric.newBuilder();
     addLabels(metricBuilder, data.getLabels(), scheme);
     metricBuilder.setCounter(counterBuilder.build());

prometheus-metrics-exposition-textformats/src/test/java/io/prometheus/metrics/expositionformats/ExpositionFormatsTest.java

@@ -192,6 +192,7 @@ public void testCounterComplete() throws IOException {
             + "value: 0.8 "
             + exemplar1protoString
             + " "
+            + "created_timestamp { seconds: 1672850385 nanos: 800000000 } "
             + "} "
             + "timestamp_ms: 1672850685829 "
             + "} "
@@ -202,6 +203,7 @@ public void testCounterComplete() throws IOException {
             + "value: 0.9 "
             + exemplar2protoString
             + " "
+            + "created_timestamp { seconds: 1672850285 } "
             + "} "
             + "timestamp_ms: 1672850585820 "
             + "}";