Adding code to check R8 rules around grpc exporters

Author: LikeTheSalad

core/consumer-rules.pro

@@ -1,4 +1,12 @@
 -dontwarn com.google.auto.value.AutoValue$Builder
 -dontwarn com.google.auto.value.AutoValue$CopyAnnotations
 -dontwarn com.google.auto.value.AutoValue
--dontwarn com.google.auto.value.extension.memoized.Memoized
+-dontwarn com.google.auto.value.extension.memoized.Memoized
+-dontwarn io.grpc.Channel
+-dontwarn io.grpc.MethodDescriptor$Builder
+-dontwarn io.grpc.MethodDescriptor$Marshaller
+-dontwarn io.grpc.MethodDescriptor$MethodType
+-dontwarn io.grpc.MethodDescriptor
+-dontwarn io.grpc.stub.AbstractFutureStub
+-dontwarn io.grpc.stub.AbstractStub$StubFactory
+-dontwarn io.grpc.stub.AbstractStub

demo-app/src/main/java/io/opentelemetry/android/demo/OtelDemoApplication.kt

@@ -10,7 +10,6 @@ import android.app.Application
 import android.util.Log
 import io.opentelemetry.android.OpenTelemetryRum
 import io.opentelemetry.android.OpenTelemetryRumBuilder
-import io.opentelemetry.android.agent.setSlowRenderingDetectionPollInterval
 import io.opentelemetry.android.config.OtelRumConfig
 import io.opentelemetry.android.features.diskbuffering.DiskBufferingConfiguration
 import io.opentelemetry.api.common.AttributeKey.stringKey
@@ -19,9 +18,9 @@ import io.opentelemetry.api.incubator.events.EventBuilder
 import io.opentelemetry.api.trace.Tracer
 import io.opentelemetry.exporter.otlp.http.logs.OtlpHttpLogRecordExporter
 import io.opentelemetry.exporter.otlp.http.trace.OtlpHttpSpanExporter
+import io.opentelemetry.exporter.otlp.logs.OtlpGrpcLogRecordExporter
+import io.opentelemetry.exporter.otlp.trace.OtlpGrpcSpanExporter
 import io.opentelemetry.sdk.logs.internal.SdkEventLoggerProvider
-import java.time.Duration
-import kotlin.math.log
 
 const val TAG = "otel.demo"
 
@@ -62,6 +61,26 @@ class OtelDemoApplication : Application() {
         } catch (e: Exception) {
             Log.e(TAG, "Oh no!", e)
         }
+
+        // This is needed to get R8 missing rules warnings.
+        initializeOtelWithGrpc()
+    }
+
+    // This is not used but it's needed to verify that our consumer proguard rules cover this use case.
+    private fun initializeOtelWithGrpc() {
+        val builder = OpenTelemetryRum.builder(this)
+            .addSpanExporterCustomizer {
+                OtlpGrpcSpanExporter.builder().build()
+            }
+            .addLogRecordExporterCustomizer {
+                OtlpGrpcLogRecordExporter.builder().build()
+            }
+
+        // This is an overly-cautious measure to prevent R8 from discarding away the whole method
+        // in case it identifies that it's actually not doing anything meaningful.
+        if (System.currentTimeMillis() < 0) {
+            print(builder)
+        }
     }
 
     companion object {