Add beans for grpc server and client metrics interceptors (#321)

* Add beans for grpc server and client metrics interceptors

* Add license

* Make factory package private

* Add tests. Add ability to disable all/client/server

* Make factory internal

micrometer-core/build.gradle

@@ -7,6 +7,7 @@ dependencies {
     api "io.micronaut:micronaut-inject:$micronautVersion"
     implementation "io.projectreactor:reactor-core"
     compileOnly "io.micronaut:micronaut-management"
+    compileOnly "io.grpc:grpc-api"
     compileOnly "io.micronaut.sql:micronaut-jdbc"
     compileOnly 'io.micronaut.cache:micronaut-cache-core'
     compileOnly "io.netty:netty-buffer"
@@ -31,4 +32,6 @@ dependencies {
     testImplementation "io.netty:netty-transport-native-epoll"
     testImplementation "io.netty:netty-transport-native-kqueue"
     testImplementation "io.micronaut:micronaut-http-server-netty"
-}
+    testImplementation "io.grpc:grpc-api"
+
+}

micrometer-core/src/main/java/io/micronaut/configuration/metrics/binder/grpc/GrpcMetricsListenerFactory.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2017-2021 original authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.micronaut.configuration.metrics.binder.grpc;
+
+import io.grpc.ClientInterceptor;
+import io.grpc.Internal;
+import io.grpc.ServerInterceptor;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.binder.grpc.MetricCollectingClientInterceptor;
+import io.micrometer.core.instrument.binder.grpc.MetricCollectingServerInterceptor;
+import io.micronaut.configuration.metrics.annotation.RequiresMetrics;
+import io.micronaut.context.annotation.Factory;
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.core.util.StringUtils;
+import jakarta.inject.Singleton;
+
+import static io.micronaut.configuration.metrics.micrometer.MeterRegistryFactory.MICRONAUT_METRICS_BINDERS;
+
+/**
+ * Provides interceptor beans to collect metrics.
+ *
+ * @author James Kleeh
+ * @since 4.1.0
+ */
+@Internal
+@RequiresMetrics
+@Requires(property = MICRONAUT_METRICS_BINDERS + ".grpc.enabled", notEquals = StringUtils.FALSE)
+@Factory
+class GrpcMetricsListenerFactory {
+
+    @Singleton
+    @Requires(classes = ServerInterceptor.class)
+    @Requires(property = MICRONAUT_METRICS_BINDERS + ".grpc.server.enabled", notEquals = StringUtils.FALSE)
+    MetricCollectingServerInterceptor grpcServerMetrics(MeterRegistry meterRegistry) {
+        return new MetricCollectingServerInterceptor(meterRegistry);
+    }
+
+    @Singleton
+    @Requires(classes = ClientInterceptor.class)
+    @Requires(property = MICRONAUT_METRICS_BINDERS + ".grpc.client.enabled", notEquals = StringUtils.FALSE)
+    MetricCollectingClientInterceptor grpcClientMetrics(MeterRegistry meterRegistry) {
+        return new MetricCollectingClientInterceptor(meterRegistry);
+    }
+}

micrometer-core/src/test/groovy/io/micronaut/configuration/metrics/binder/grpc/GrpcMetricsBinderSpec.groovy

@@ -0,0 +1,77 @@
+package io.micronaut.configuration.metrics.binder.grpc
+
+import io.micrometer.core.instrument.binder.grpc.MetricCollectingClientInterceptor
+import io.micrometer.core.instrument.binder.grpc.MetricCollectingServerInterceptor
+import io.micronaut.context.ApplicationContext
+import spock.lang.Specification
+
+class GrpcMetricsBinderSpec extends Specification {
+
+    void "test beans are created by default"() {
+        given:
+        ApplicationContext ctx = ApplicationContext.run()
+
+        expect:
+        ctx.containsBean(MetricCollectingServerInterceptor)
+        ctx.containsBean(MetricCollectingClientInterceptor)
+
+        cleanup:
+        ctx.close()
+    }
+
+    void "test disabling all grpc metrics"() {
+        given:
+        ApplicationContext ctx = ApplicationContext.run([
+                "micronaut.metrics.binders.grpc.enabled": false
+        ])
+
+        expect:
+        !ctx.containsBean(MetricCollectingServerInterceptor)
+        !ctx.containsBean(MetricCollectingClientInterceptor)
+
+        cleanup:
+        ctx.close()
+    }
+
+    void "test disabling all metrics"() {
+        given:
+        ApplicationContext ctx = ApplicationContext.run([
+                "micronaut.metrics.enabled": false
+        ])
+
+        expect:
+        !ctx.containsBean(MetricCollectingServerInterceptor)
+        !ctx.containsBean(MetricCollectingClientInterceptor)
+
+        cleanup:
+        ctx.close()
+    }
+
+    void "test disabling client grpc metrics"() {
+        given:
+        ApplicationContext ctx = ApplicationContext.run([
+                "micronaut.metrics.binders.grpc.client.enabled": false
+        ])
+
+        expect:
+        ctx.containsBean(MetricCollectingServerInterceptor)
+        !ctx.containsBean(MetricCollectingClientInterceptor)
+
+        cleanup:
+        ctx.close()
+    }
+
+    void "test disabling server grpc metrics"() {
+        given:
+        ApplicationContext ctx = ApplicationContext.run([
+                "micronaut.metrics.binders.grpc.server.enabled": false
+        ])
+
+        expect:
+        !ctx.containsBean(MetricCollectingServerInterceptor)
+        ctx.containsBean(MetricCollectingClientInterceptor)
+
+        cleanup:
+        ctx.close()
+    }
+}