Monitoring API - write framework adapters

Change-Id: Iaba9c4ef6022d01c1f572055316700a3a4dfa8f2
Issue-ID: DCAEGEN2-1589
Signed-off-by: Piotr Jaszczyk <piotr.jaszczyk@nokia.com>

4 files changed, 322 insertions, 0 deletions

diff --git a/standardization/moher-api/server-adapters/reactor-netty/src/main/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/HealthRoutes.java b/standardization/moher-api/server-adapters/reactor-netty/src/main/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/HealthRoutes.java
new file mode 100644
index 00000000..1b6411de
--- /dev/null
+++ b/standardization/moher-api/server-adapters/reactor-netty/src/main/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/HealthRoutes.java
@@ -0,0 +1,80 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * 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.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.standardization.moher.adapters.reactornetty;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import java.util.function.Consumer;
+import org.onap.dcaegen2.services.sdk.standardization.moher.health.api.AliveMessage;
+import org.onap.dcaegen2.services.sdk.standardization.moher.health.api.GsonAdaptersHealth;
+import org.onap.dcaegen2.services.sdk.standardization.moher.health.api.Health;
+import org.onap.dcaegen2.services.sdk.standardization.moher.health.api.HealthProvider;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Mono;
+import reactor.netty.http.server.HttpServerRequest;
+import reactor.netty.http.server.HttpServerResponse;
+import reactor.netty.http.server.HttpServerRoutes;
+
+public class HealthRoutes implements Consumer<HttpServerRoutes> {
+
+    public static final String APPLICATION_JSON = "application/json";
+    private final Gson gson;
+    private final HealthProvider healthProvider;
+
+    public HealthRoutes(Gson gson,
+            HealthProvider healthProvider) {
+        this.gson = gson;
+        this.healthProvider = healthProvider;
+    }
+
+    public static HealthRoutes create(HealthProvider healthProvider) {
+        GsonBuilder gson = new GsonBuilder();
+        gson.registerTypeAdapterFactory(new GsonAdaptersHealth());
+        return new HealthRoutes(gson.create(), healthProvider);
+    }
+
+    @Override
+    public void accept(HttpServerRoutes routes) {
+        routes.get("/health/ready", this::readinessCheck);
+        routes.get("/health/alive", this::livenessCheck);
+    }
+
+    private Publisher<Void> readinessCheck(HttpServerRequest httpServerRequest, HttpServerResponse httpServerResponse) {
+        return healthProvider.currentHealth()
+                .flatMapMany(health ->
+                        httpServerResponse.status(statusForHealth(health))
+                                .header(HttpHeaderNames.CONTENT_TYPE, APPLICATION_JSON)
+                                .sendString(Mono.just(health).map(gson::toJson))
+                );
+    }
+
+    private Publisher<Void> livenessCheck(HttpServerRequest httpServerRequest, HttpServerResponse httpServerResponse) {
+        return httpServerResponse.status(HttpResponseStatus.OK)
+                .header(HttpHeaderNames.CONTENT_TYPE, APPLICATION_JSON)
+                .sendString(Mono.just(AliveMessage.ALIVE_MESSAGE_JSON));
+    }
+
+    private HttpResponseStatus statusForHealth(Health health) {
+        return health.healthy() ? HttpResponseStatus.OK : HttpResponseStatus.SERVICE_UNAVAILABLE;
+    }
+}
diff --git a/standardization/moher-api/server-adapters/reactor-netty/src/main/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/MetricsRoutes.java b/standardization/moher-api/server-adapters/reactor-netty/src/main/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/MetricsRoutes.java
new file mode 100644
index 00000000..b6db874d
--- /dev/null
+++ b/standardization/moher-api/server-adapters/reactor-netty/src/main/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/MetricsRoutes.java
@@ -0,0 +1,49 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * 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.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.standardization.moher.adapters.reactornetty;
+
+import java.util.function.Consumer;
+import org.onap.dcaegen2.services.sdk.standardization.moher.metrics.api.Metrics;
+import org.reactivestreams.Publisher;
+import reactor.netty.http.server.HttpServerRequest;
+import reactor.netty.http.server.HttpServerResponse;
+import reactor.netty.http.server.HttpServerRoutes;
+
+public class MetricsRoutes implements Consumer<HttpServerRoutes> {
+
+    private final Metrics metrics;
+
+    public MetricsRoutes(Metrics metrics) {
+        this.metrics = metrics;
+    }
+
+    @Override
+    public void accept(HttpServerRoutes routes) {
+        routes.get("/metrics", this::prometheusMetrics);
+    }
+
+    private Publisher<Void> prometheusMetrics(
+            HttpServerRequest httpServerRequest,
+            HttpServerResponse httpServerResponse) {
+        return httpServerResponse.sendString(metrics.collect());
+    }
+
+}
diff --git a/standardization/moher-api/server-adapters/reactor-netty/src/test/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/HealthRoutesIT.java b/standardization/moher-api/server-adapters/reactor-netty/src/test/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/HealthRoutesIT.java
new file mode 100644
index 00000000..367f50e3
--- /dev/null
+++ b/standardization/moher-api/server-adapters/reactor-netty/src/test/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/HealthRoutesIT.java
@@ -0,0 +1,122 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * 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.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.standardization.moher.adapters.reactornetty;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import java.nio.charset.StandardCharsets;
+import java.time.Duration;
+import java.util.concurrent.atomic.AtomicReference;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.HttpMethod;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.HttpResponse;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.ImmutableHttpRequest;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.RxHttpClient;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.RxHttpClientFactory;
+import org.onap.dcaegen2.services.sdk.standardization.moher.health.api.AliveMessage;
+import org.onap.dcaegen2.services.sdk.standardization.moher.health.api.GsonAdaptersHealth;
+import org.onap.dcaegen2.services.sdk.standardization.moher.health.api.Health;
+import org.onap.dcaegen2.services.sdk.standardization.moher.health.api.HealthProvider;
+import reactor.netty.DisposableServer;
+import reactor.netty.http.server.HttpServer;
+
+class HealthRoutesIT {
+
+    private static final Duration TIMEOUT = Duration.ofSeconds(5);
+    private final AtomicReference<Health> currentHealth = new AtomicReference<>();
+    private final HealthRoutes sut = HealthRoutes.create(HealthProvider.fromSupplier(currentHealth::get));
+    private final RxHttpClient rxHttpClient = RxHttpClientFactory.create();
+    private final Gson gsonForDeserialization = new GsonBuilder()
+            .registerTypeAdapterFactory(new GsonAdaptersHealth())
+            .create();
+    private DisposableServer server;
+    private String baseUrl;
+
+    @BeforeEach
+    void setUp() {
+        server = HttpServer.create().route(sut).bindNow();
+        baseUrl = String.format("http://%s:%d", server.host(), server.port());
+    }
+
+    @AfterEach
+    void tearDown() {
+        server.disposeNow(TIMEOUT);
+    }
+
+    @Test
+    void readinessProbeShouldReturnOkWhenHealthy() {
+        // given
+        final Health expectedHealth = Health.createHealthy("Ready to go");
+        currentHealth.set(expectedHealth);
+        final String url = baseUrl + "/health/ready";
+
+        // when
+        final HttpResponse response = rxHttpClient
+                .call(ImmutableHttpRequest.builder().method(HttpMethod.GET).url(url).build())
+                .block(TIMEOUT);
+
+        // then
+        assertThat(response.successful()).describedAs("response should be successful").isTrue();
+        final Health actualHealth = response.bodyAsJson(StandardCharsets.UTF_8, gsonForDeserialization, Health.class);
+        assertThat(actualHealth).describedAs("response body").isEqualTo(expectedHealth);
+    }
+
+    @Test
+    void readinessProbeShouldReturnUnavailableWhenNotHealthy() {
+        // given
+        final Health expectedHealth = Health.createUnhealthy("Waiting for CBS update");
+        currentHealth.set(expectedHealth);
+        final String url = baseUrl + "/health/ready";
+
+        // when
+        final HttpResponse response = rxHttpClient
+                .call(ImmutableHttpRequest.builder().method(HttpMethod.GET).url(url).build())
+                .block(TIMEOUT);
+
+        // then
+        assertThat(response.statusCode()).describedAs("response status code")
+                .isGreaterThanOrEqualTo(500)
+                .isLessThan(600);
+        assertThat(response.successful()).describedAs("response should not be successful").isFalse();
+        final Health actualHealth = response.bodyAsJson(StandardCharsets.UTF_8, gsonForDeserialization, Health.class);
+        assertThat(actualHealth).describedAs("response body").isEqualTo(expectedHealth);
+    }
+
+    @Test
+    void livenessProbeShouldAlwaysReturnOk() {
+        // given
+        final String url = baseUrl + "/health/alive";
+
+        // when
+        final HttpResponse response = rxHttpClient
+                .call(ImmutableHttpRequest.builder().method(HttpMethod.GET).url(url).build())
+                .block(TIMEOUT);
+
+        // then
+        assertThat(response.successful()).describedAs("response should be successful").isTrue();
+        assertThat(response.bodyAsString()).describedAs("response body").isEqualTo(AliveMessage.ALIVE_MESSAGE_JSON);
+    }
+
+}
\ No newline at end of file
diff --git a/standardization/moher-api/server-adapters/reactor-netty/src/test/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/MetricsRoutesIT.java b/standardization/moher-api/server-adapters/reactor-netty/src/test/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/MetricsRoutesIT.java
new file mode 100644
index 00000000..55c24c73
--- /dev/null
+++ b/standardization/moher-api/server-adapters/reactor-netty/src/test/java/org/onap/dcaegen2/services/sdk/standardization/moher/adapters/reactornetty/MetricsRoutesIT.java
@@ -0,0 +1,71 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * 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.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.standardization.moher.adapters.reactornetty;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.time.Duration;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.HttpMethod;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.HttpResponse;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.ImmutableHttpRequest;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.RxHttpClient;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.RxHttpClientFactory;
+import org.onap.dcaegen2.services.sdk.standardization.moher.metrics.api.Metrics;
+import org.onap.dcaegen2.services.sdk.standardization.moher.metrics.api.MetricsFactory;
+import reactor.netty.DisposableServer;
+import reactor.netty.http.server.HttpServer;
+
+class MetricsRoutesIT {
+
+    private static final Duration TIMEOUT = Duration.ofSeconds(5);
+    private final Metrics metrics = MetricsFactory.createMetrics(MetricsFactory.createDefaultRegistry());
+    private final MetricsRoutes sut = new MetricsRoutes(metrics);
+    private final RxHttpClient rxHttpClient = RxHttpClientFactory.create();
+    private DisposableServer server;
+
+    @BeforeEach
+    void setUp() {
+        server = HttpServer.create().route(sut).bindNow();
+    }
+
+    @AfterEach
+    void tearDown() {
+        server.disposeNow(TIMEOUT);
+    }
+
+    @Test
+    void prometheusMetrics() {
+        // given
+        final String url = String.format("http://%s:%d/metrics", server.host(), server.port());
+
+        // when
+        final HttpResponse response = rxHttpClient
+                .call(ImmutableHttpRequest.builder().method(HttpMethod.GET).url(url).build())
+                .block(TIMEOUT);
+
+        // then
+        assertThat(response.successful()).describedAs("response should be successfull").isTrue();
+        assertThat(response.bodyAsString()).describedAs("response body").contains("system_cpu", "jvm_classes");
+    }
+}
\ No newline at end of file