Issue ReactiveX#72: Created a CircuitBreakerMetrics class which can b…

…e used to export CircuitBreaker.Metrics as Dropwizard Metrics Gauges.

resilience4j-metrics/build.gradle

@@ -1,4 +1,6 @@
 dependencies {
     compile (libraries.metrics)
+    compileOnly project(':resilience4j-circuitbreaker')
     testCompile project(':resilience4j-test')
+    testCompile project(':resilience4j-circuitbreaker')
 }

resilience4j-metrics/src/main/java/io/github/resilience4j/metrics/CircuitBreakerMetrics.java

@@ -0,0 +1,77 @@
+/*
+ *
+ *  Copyright 2017: Robert Winkler
+ *
+ *  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
+ *
+ *         http://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.github.resilience4j.metrics;
+
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.Metric;
+import com.codahale.metrics.MetricRegistry;
+import com.codahale.metrics.MetricSet;
+
+import java.util.Map;
+
+import io.github.resilience4j.circuitbreaker.CircuitBreaker;
+import io.github.resilience4j.circuitbreaker.CircuitBreakerRegistry;
+import javaslang.collection.Array;
+import javaslang.collection.Seq;
+
+import static com.codahale.metrics.MetricRegistry.name;
+
+/**
+ * An adapter which exports {@link CircuitBreaker.Metrics} as Dropwizard Metrics Gauges.
+ */
+public class CircuitBreakerMetrics implements MetricSet{
+
+    private final MetricRegistry metricRegistry = new MetricRegistry();
+
+    private CircuitBreakerMetrics(Seq<CircuitBreaker> circuitBreakers){
+        circuitBreakers.forEach(circuitBreaker -> {
+            String name = circuitBreaker.getName();
+            CircuitBreaker.Metrics metrics = circuitBreaker.getMetrics();
+
+            metricRegistry.register(name("resilience4j.circuitbreaker", name, "successful"),
+                    (Gauge<Integer>) metrics::getNumberOfSuccessfulCalls);
+            metricRegistry.register(name("resilience4j.circuitbreaker", name, "failed"),
+                    (Gauge<Integer>) metrics::getNumberOfFailedCalls);
+            metricRegistry.register(name("resilience4j.circuitbreaker", name, "not_permitted"),
+                    (Gauge<Long>) metrics::getNumberOfNotPermittedCalls);
+            metricRegistry.register(name("resilience4j.circuitbreaker", name, "buffered"),
+                    (Gauge<Integer>) metrics::getNumberOfBufferedCalls);
+            metricRegistry.register(name("resilience4j.circuitbreaker", name, "buffered_max"),
+                    (Gauge<Integer>) metrics::getMaxNumberOfBufferedCalls);
+            }
+        );
+    }
+
+    public static CircuitBreakerMetrics of(CircuitBreakerRegistry circuitBreakerRegistry) {
+        return new CircuitBreakerMetrics(circuitBreakerRegistry.getAllCircuitBreakers());
+    }
+
+    public static CircuitBreakerMetrics of(Seq<CircuitBreaker> circuitBreakers) {
+        return new CircuitBreakerMetrics(circuitBreakers);
+    }
+
+    public static CircuitBreakerMetrics of(CircuitBreaker circuitBreaker) {
+        return new CircuitBreakerMetrics(Array.of(circuitBreaker));
+    }
+
+    @Override
+    public Map<String, Metric> getMetrics() {
+        return metricRegistry.getMetrics();
+    }
+}

resilience4j-metrics/src/test/java/io/github/resilience4j/metrics/CircuitBreakerMetricsTest.java

@@ -0,0 +1,71 @@
+/*
+ *
+ *  Copyright 2017: Robert Winkler
+ *
+ *  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
+ *
+ *         http://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.github.resilience4j.metrics;
+
+import com.codahale.metrics.MetricRegistry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.BDDMockito;
+
+import io.github.resilience4j.circuitbreaker.CircuitBreaker;
+import io.github.resilience4j.circuitbreaker.CircuitBreakerRegistry;
+import io.github.resilience4j.test.HelloWorldService;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+
+public class CircuitBreakerMetricsTest {
+
+    private MetricRegistry metricRegistry;
+    private HelloWorldService helloWorldService;
+
+    @Before
+    public void setUp(){
+        metricRegistry = new MetricRegistry();
+        helloWorldService = mock(HelloWorldService.class);
+    }
+
+    @Test
+    public void shouldRegisterMetrics() throws Throwable {
+        //Given
+        CircuitBreakerRegistry circuitBreakerRegistry = CircuitBreakerRegistry.ofDefaults();
+        CircuitBreaker circuitBreaker = circuitBreakerRegistry.circuitBreaker("testName");
+        metricRegistry.registerAll(CircuitBreakerMetrics.of(circuitBreakerRegistry));
+
+        // Given the HelloWorldService returns Hello world
+        BDDMockito.given(helloWorldService.returnHelloWorld()).willReturn("Hello world");
+
+        //When
+        String value = circuitBreaker.executeSupplier(helloWorldService::returnHelloWorld);
+
+        //Then
+        assertThat(value).isEqualTo("Hello world");
+        // Then the helloWorldService should be invoked 1 time
+        BDDMockito.then(helloWorldService).should(times(1)).returnHelloWorld();
+        assertThat(metricRegistry.getMetrics()).hasSize(5);
+        assertThat(metricRegistry.getGauges().get("resilience4j.circuitbreaker.testName.buffered").getValue()).isEqualTo(1);
+        assertThat(metricRegistry.getGauges().get("resilience4j.circuitbreaker.testName.successful").getValue()).isEqualTo(1);
+        assertThat(metricRegistry.getGauges().get("resilience4j.circuitbreaker.testName.failed").getValue()).isEqualTo(0);
+        assertThat(metricRegistry.getGauges().get("resilience4j.circuitbreaker.testName.not_permitted").getValue()).isEqualTo(0L);
+        assertThat(metricRegistry.getGauges().get("resilience4j.circuitbreaker.testName.buffered_max").getValue()).isEqualTo(100);
+
+    }
+}

resilience4j-prometheus/build.gradle

@@ -1,5 +1,7 @@
 dependencies {
     compile (libraries.prometheus_simpleclient)
-    compile project(':resilience4j-circuitbreaker')
-    compile project(':resilience4j-ratelimiter')
+    compileOnly project(':resilience4j-circuitbreaker')
+    compileOnly project(':resilience4j-ratelimiter')
+    testCompile project(':resilience4j-circuitbreaker')
+    testCompile project(':resilience4j-ratelimiter')
 }

resilience4j-spring-boot/src/main/java/io/github/resilience4j/circuitbreaker/autoconfigure/CircuitBreakerAutoConfiguration.java

@@ -39,8 +39,13 @@
 public class CircuitBreakerAutoConfiguration {
 
     @Bean
-    public CircuitBreakerRegistry circuitBreakerRegistry(){
-        return new InMemoryCircuitBreakerRegistry();
+    public CircuitBreakerRegistry circuitBreakerRegistry(CircuitBreakerProperties circuitBreakerProperties){
+        CircuitBreakerRegistry circuitBreakerRegistry = new InMemoryCircuitBreakerRegistry();
+        circuitBreakerProperties.getBackends().forEach(
+                (name, properties) -> circuitBreakerRegistry.circuitBreaker(name, circuitBreakerProperties
+                        .createCircuitBreakerConfig(name))
+        );
+        return circuitBreakerRegistry;
     }
 
     @Bean