🐛 Fix incorrect metrics endpoint (#361)

* ✅ add unit test reproducing issue where metric reporting endpoint would only default to trace reporting endpoint if trace reporting endpoint was supplied via env var

* 🐛 fix bug with metric reporting endpoint not falling back to reporting endpoint when supplied via YAML

* ✅ add test test for non default metrics reporting endpoint

* Revert "🐛 fix bug with metric reporting endpoint not falling back to reporting endpoint when supplied via YAML"

This reverts commit 2c70107.

* 🐛 fix bug more simply

* 💡 fix comments in tests

otel-extensions/src/main/java/org/hypertrace/agent/otel/extensions/config/HypertraceConfig.java

@@ -140,6 +140,9 @@ private static Reporting.Builder applyReportingDefaults(Reporting.Builder builde
     if (!builder.hasEndpoint()) {
       builder.setEndpoint(StringValue.newBuilder().setValue(DEFAULT_REPORTING_ENDPOINT).build());
     }
+    if (builder.getTraceReporterType().equals(TraceReporterType.UNSPECIFIED)) {
+      builder.setTraceReporterType(TraceReporterType.OTLP);
+    }
     if (!builder.hasMetricEndpoint()) {
       if (TraceReporterType.OTLP.equals(builder.getTraceReporterType())) {
         // If trace reporter type is OTLP, use the same endpoint for metrics
@@ -149,9 +152,6 @@ private static Reporting.Builder applyReportingDefaults(Reporting.Builder builde
             StringValue.newBuilder().setValue(DEFAULT_REPORTING_ENDPOINT).build());
       }
     }
-    if (builder.getTraceReporterType().equals(TraceReporterType.UNSPECIFIED)) {
-      builder.setTraceReporterType(TraceReporterType.OTLP);
-    }
     if (builder
         .getMetricReporterType()
         .equals(MetricReporterType.METRIC_REPORTER_TYPE_UNSPECIFIED)) {

otel-extensions/src/test/java/org/hypertrace/agent/otel/extensions/config/HypertraceConfigTest.java

@@ -205,4 +205,38 @@ public void noneTraceExporter() throws IOException {
         HypertraceConfig.DEFAULT_REPORTING_ENDPOINT,
         agentConfig.getReporting().getMetricEndpoint().getValue());
   }
+
+  @Test
+  void nonDefaultReportingEndpoint() throws IOException {
+    // GIVEN a config file with a non-default reporting endpoint
+    URL resource = getClass().getClassLoader().getResource("nonDefaultReportingEndpoint.yaml");
+    // WHEN we load the config
+    AgentConfig agentConfig = HypertraceConfig.load(resource.getPath());
+    // VERIFY the trace reporting type is OTLP
+    Assertions.assertEquals(
+        TraceReporterType.OTLP, agentConfig.getReporting().getTraceReporterType());
+    String expectedReportingEndpoint = "http://example.com:4317";
+    // VERIFY the trace reporting and metric reporting endpoints are both the specified value
+    Assertions.assertEquals(
+        expectedReportingEndpoint, agentConfig.getReporting().getEndpoint().getValue());
+    Assertions.assertEquals(
+        expectedReportingEndpoint, agentConfig.getReporting().getMetricEndpoint().getValue());
+  }
+
+  @Test
+  void nonDefaultMetricsEndpoint() throws IOException {
+    // GIVEN a config file with a non-default metric reporting endpoint
+    URL resource = getClass().getClassLoader().getResource("nonDefaultMetricsEndpoint.yaml");
+    // WHEN we load the config
+    AgentConfig agentConfig = HypertraceConfig.load(resource.getPath());
+    // VERIFY the trace reporting type is OTLP
+    Assertions.assertEquals(
+        TraceReporterType.OTLP, agentConfig.getReporting().getTraceReporterType());
+    // VERIFY the trace reporting endpoint is still the default value
+    Assertions.assertEquals(
+        "http://localhost:4317", agentConfig.getReporting().getEndpoint().getValue());
+    // VERIFY the metric reporting endpoint is the specified value
+    Assertions.assertEquals(
+        "http://example.com:4317", agentConfig.getReporting().getMetricEndpoint().getValue());
+  }
 }

otel-extensions/src/test/resources/nonDefaultMetricsEndpoint.yaml

@@ -0,0 +1,3 @@
+service_name: service
+reporting:
+  metric_endpoint: http://example.com:4317

otel-extensions/src/test/resources/nonDefaultReportingEndpoint.yaml

@@ -0,0 +1,3 @@
+service_name: service
+reporting:
+  endpoint: http://example.com:4317