Convert PrometheusSupport from a reactive WebServer Service to a HelidonFeatureSupport

metrics/prometheus/pom.xml

@@ -31,8 +31,8 @@
 
     <dependencies>
         <dependency>
-            <groupId>io.helidon.reactive.webserver</groupId>
-            <artifactId>helidon-reactive-webserver</artifactId>
+            <groupId>io.helidon.nima.service-common</groupId>
+            <artifactId>helidon-nima-service-common</artifactId>
         </dependency>
         <dependency>
             <groupId>io.prometheus</groupId>
@@ -49,13 +49,8 @@
             <scope>test</scope>
         </dependency>
         <dependency>
-            <groupId>org.mockito</groupId>
-            <artifactId>mockito-core</artifactId>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>io.helidon.reactive.webserver</groupId>
-            <artifactId>helidon-reactive-webserver-test-support</artifactId>
+            <groupId>io.helidon.nima.testing.junit5</groupId>
+            <artifactId>helidon-nima-testing-junit5-webserver</artifactId>
             <scope>test</scope>
         </dependency>
     </dependencies>

metrics/prometheus/src/main/java/io/helidon/metrics/prometheus/PrometheusSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2017, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,30 +19,33 @@
 import java.util.Enumeration;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 
 import io.helidon.common.http.HttpMediaType;
-import io.helidon.reactive.webserver.Routing;
-import io.helidon.reactive.webserver.ServerRequest;
-import io.helidon.reactive.webserver.ServerResponse;
-import io.helidon.reactive.webserver.Service;
+import io.helidon.nima.servicecommon.HelidonFeatureSupport;
+import io.helidon.nima.webserver.http.HttpRouting;
+import io.helidon.nima.webserver.http.HttpRules;
+import io.helidon.nima.webserver.http.HttpService;
+import io.helidon.nima.webserver.http.ServerRequest;
+import io.helidon.nima.webserver.http.ServerResponse;
 
 import io.prometheus.client.Collector;
 import io.prometheus.client.CollectorRegistry;
 
 /**
  * Support for Prometheus client endpoint.
  * <p>
- * Default and simplest use on {@link Routing} creates {@code /metrics} endpoint
+ * Default and simplest use on {@link HttpRouting} creates {@code /metrics} endpoint
  * for {@link CollectorRegistry default CollectorRegistry}.
  * <pre>{@code
- * Routing.builder()
- *        .register(PrometheusSupport.create())
+ * HttpRouting.builder()
+ *        ..addFeature(PrometheusSupport.create())
  * }</pre>
- * <p>
- * It is possible to use
  */
-public final class PrometheusSupport implements Service {
+public final class PrometheusSupport extends HelidonFeatureSupport {
+
+    private static final System.Logger LOGGER = System.getLogger(PrometheusSupport.class.getName());
 
     /**
      * Standard path of Prometheus client resource: {@code /metrics}.
@@ -54,18 +57,23 @@ public final class PrometheusSupport implements Service {
     private final CollectorRegistry collectorRegistry;
     private final String path;
 
-    private PrometheusSupport(CollectorRegistry collectorRegistry, String path) {
-        this.collectorRegistry = collectorRegistry == null ? CollectorRegistry.defaultRegistry : collectorRegistry;
-        this.path = path == null ? DEFAULT_PATH : path;
+    private PrometheusSupport(Builder builder) {
+        super(LOGGER, builder, "prometheus");
+        this.collectorRegistry = builder.registry;
+        this.path = builder.path;
     }
 
-    @Override
-    public void update(Routing.Rules rules) {
+    private void configureRoutes(HttpRules rules) {
         rules.get(path, this::process);
     }
 
+    @Override
+    public Optional<HttpService> service() {
+            return Optional.of(this::configureRoutes);
+    }
+
     private void process(ServerRequest req, ServerResponse res) {
-        Set<String> filters = new HashSet<>(req.queryParams().all("name[]", List::of));
+        Set<String> filters = new HashSet<>(req.query().all("name[]", List::of));
         Enumeration<Collector.MetricFamilySamples> mfs = collectorRegistry.filteredMetricFamilySamples(filters);
         res.headers().contentType(CONTENT_TYPE);
         res.send(compose(mfs));
@@ -171,7 +179,7 @@ private static String typeString(Collector.Type t) {
      * @see #builder()
      */
     public static PrometheusSupport create(CollectorRegistry collectorRegistry) {
-        return new PrometheusSupport(collectorRegistry, DEFAULT_PATH);
+        return builder().collectorRegistry(collectorRegistry).build();
     }
 
     /**
@@ -183,7 +191,7 @@ public static PrometheusSupport create(CollectorRegistry collectorRegistry) {
      * @see #builder()
      */
     public static PrometheusSupport create() {
-        return create(null);
+        return builder().build();
     }
 
     /**
@@ -200,12 +208,13 @@ public static Builder builder() {
     /**
      * A builder of {@link PrometheusSupport}.
      */
-    public static final class Builder implements io.helidon.common.Builder<Builder, PrometheusSupport> {
+    public static final class Builder extends HelidonFeatureSupport.Builder<Builder, PrometheusSupport> {
 
         private CollectorRegistry registry = CollectorRegistry.defaultRegistry;
-        private String path;
+        private String path = DEFAULT_PATH;
 
         private Builder() {
+            super("/");
         }
 
         /**
@@ -236,7 +245,7 @@ public Builder path(String path) {
 
         @Override
         public PrometheusSupport build() {
-            return new PrometheusSupport(registry, path == null ? DEFAULT_PATH : path);
+            return new PrometheusSupport(this);
         }
     }
 }

metrics/prometheus/src/main/java/module-info.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2018, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,8 +18,7 @@
  * Prometheus support.
  */
 module io.helidon.metrics.prometheus {
-    requires io.helidon.reactive.webserver;
-
+    requires io.helidon.nima.servicecommon;
     // prometheus :(
     requires simpleclient;
 

metrics/prometheus/src/test/java/io/helidon/metrics/prometheus/PrometheusSupportTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2017, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,17 +16,17 @@
 
 package io.helidon.metrics.prometheus;
 
-import java.util.concurrent.TimeUnit;
-
 import io.helidon.common.http.Http;
-import io.helidon.reactive.webserver.Routing;
-import io.helidon.reactive.webserver.testsupport.TestClient;
-import io.helidon.reactive.webserver.testsupport.TestRequest;
-import io.helidon.reactive.webserver.testsupport.TestResponse;
+import io.helidon.nima.testing.junit5.webserver.ServerTest;
+import io.helidon.nima.testing.junit5.webserver.SetUpRoute;
+import io.helidon.nima.webclient.http1.Http1Client;
+import io.helidon.nima.webclient.http1.Http1ClientResponse;
+import io.helidon.nima.webserver.http.HttpRouting;
 
 import io.prometheus.client.CollectorRegistry;
 import io.prometheus.client.Counter;
 import org.hamcrest.core.StringStartsWith;
+import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -35,20 +35,25 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.IsNot.not;
 
+@ServerTest
 public class PrometheusSupportTest {
 
-    private Routing routing;
     private Counter alpha;
     private Counter beta;
+    private static CollectorRegistry registry = new CollectorRegistry();
+    private final Http1Client client;
+
+    PrometheusSupportTest(Http1Client client) {
+        this.client = client;
+    }
+
+    @SetUpRoute
+    static void routing(HttpRouting.Builder builder){
+        builder.addFeature(PrometheusSupport.create(registry)).build();
+    }
 
     @BeforeEach
-    public void prepareRouting() {
-        CollectorRegistry registry = new CollectorRegistry();
-        // Routing
-        this.routing = Routing.builder()
-                .register(PrometheusSupport.create(registry))
-                .build();
-        // Metrics
+    public void prepareRegistry() {
         this.alpha = Counter.build()
                                .name("alpha")
                                .help("Alpha help with \\ and \n.")
@@ -69,54 +74,53 @@ public void prepareRouting() {
         }
     }
 
-    private TestResponse doTestRequest(String nameQuery) throws Exception {
-        TestRequest request = TestClient.create(routing)
-                                        .path("/metrics");
-        if (nameQuery != null && !nameQuery.isEmpty()) {
-            request.queryParameter("name[]", nameQuery);
-        }
-        TestResponse response = request.get();
-        assertThat(response.status(), is(Http.Status.OK_200));
-        return response;
+    @AfterEach
+    public void clearRegistry() {
+        registry.clear();
     }
 
     @Test
-    public void simpleCall() throws Exception {
-        TestResponse response = doTestRequest(null);
-        assertThat(response.headers().first(Http.Header.CONTENT_TYPE).orElse(null),
-                   StringStartsWith.startsWith("text/plain"));
-        String body = response.asString().get(5, TimeUnit.SECONDS);
-        assertThat(body, containsString("# HELP beta"));
-        assertThat(body, containsString("# TYPE beta counter"));
-        assertThat(body, containsString("beta 3.0"));
-        assertThat(body, containsString("# TYPE alpha counter"));
-        assertThat(body, containsString("# HELP alpha Alpha help with \\\\ and \\n."));
-        assertThat(body, containsString("alpha{method=\"bar\",} 6.0"));
-        assertThat(body, containsString("alpha{method=\"\\\"foo\\\" \\\\ \\n\",} 5.0"));
+    public void simpleCall() {
+        try (Http1ClientResponse response = client.get("/metrics").request()) {
+            assertThat(response.status(), is(Http.Status.OK_200));
+            assertThat(response.headers().first(Http.Header.CONTENT_TYPE).orElse(null),
+                    StringStartsWith.startsWith("text/plain"));
+            String body = response.as(String.class);
+            assertThat(body, containsString("# HELP beta"));
+            assertThat(body, containsString("# TYPE beta counter"));
+            assertThat(body, containsString("beta 3.0"));
+            assertThat(body, containsString("# TYPE alpha counter"));
+            assertThat(body, containsString("# HELP alpha Alpha help with \\\\ and \\n."));
+            assertThat(body, containsString("alpha{method=\"bar\",} 6.0"));
+            assertThat(body, containsString("alpha{method=\"\\\"foo\\\" \\\\ \\n\",} 5.0"));
+        }
     }
 
     @Test
-    public void doubleCall() throws Exception {
-        TestResponse response = doTestRequest(null);
-        assertThat(response.headers().first(Http.Header.CONTENT_TYPE).orElse(null),
-                   StringStartsWith.startsWith("text/plain"));
-        String body = response.asString().get(5, TimeUnit.SECONDS);
-        assertThat(body, containsString("alpha{method=\"bar\",} 6.0"));
-        assertThat(body, not(containsString("alpha{method=\"baz\"")));
-        alpha.labels("baz").inc();
-        response = doTestRequest(null);
-        body = response.asString().get(5, TimeUnit.SECONDS);
-        assertThat(body, containsString("alpha{method=\"baz\",} 1.0"));
+    public void doubleCall() {
+        try (Http1ClientResponse response = client.get("/metrics").request()) {
+            assertThat(response.headers().first(Http.Header.CONTENT_TYPE).orElse(null),
+                    StringStartsWith.startsWith("text/plain"));
+            String body = response.as(String.class);
+            assertThat(body, containsString("alpha{method=\"bar\",} 6.0"));
+            assertThat(body, not(containsString("alpha{method=\"baz\"")));
+            alpha.labels("baz").inc();
+        }
+        try (Http1ClientResponse response = client.get("/metrics").request()) {
+            String body = response.as(String.class);
+            assertThat(body, containsString("alpha{method=\"baz\",} 1.0"));
+        }
     }
 
     @Test
-    public void filter() throws Exception {
-        TestResponse response = doTestRequest("alpha");
-        assertThat(response.status(), is(Http.Status.OK_200));
-        String body = response.asString().get(5, TimeUnit.SECONDS);
-        assertThat(body, not(containsString("# TYPE beta")));
-        assertThat(body, not(containsString("beta 3.0")));
-        assertThat(body, containsString("# TYPE alpha counter"));
-        assertThat(body, containsString("alpha{method=\"bar\",} 6.0"));
+    public void filter() {
+        try (Http1ClientResponse response = client.get("/metrics").queryParam("name[]", "alpha").request()) {
+            assertThat(response.status(), is(Http.Status.OK_200));
+            String body = response.as(String.class);
+            assertThat(body, not(containsString("# TYPE beta")));
+            assertThat(body, not(containsString("beta 3.0")));
+            assertThat(body, containsString("# TYPE alpha counter"));
+            assertThat(body, containsString("alpha{method=\"bar\",} 6.0"));
+        }
     }
 }