feat: Health endpoints (#111)

Signed-off-by: Alfredo Gutierrez <[email protected]>

charts/hedera-block-node/templates/deployment.yaml

@@ -40,16 +40,14 @@ spec:
               name: {{ include "hedera-block-node.fullname" . }}-config
           - secretRef:
               name: {{ include "hedera-block-node.fullname" . }}-secret
-
-        # TODO: Uncomment them once we have the health and readiness probes in our application
-        #livenessProbe:
-        #  httpGet:
-        #    path: /health # we need to define this in our application
-        #    port: 8080 # will be the same as server port?
-        #readinessProbe:
-        #    httpGet:
-        #      path: /ready # we need to define this in our application
-        #      port: 8080 # will be the same as server port?
+        livenessProbe:
+          httpGet:
+            path: {{ .Values.blockNode.health.liveness.endpoint }}
+            port: {{ .Values.service.port }}
+        readinessProbe:
+          httpGet:
+            path: {{ .Values.blockNode.health.readiness.endpoint }}
+            port: {{ .Values.service.port }}
       {{- with .Values.nodeSelector }}
       nodeSelector:
         {{- toYaml . | nindent 8 }}

charts/hedera-block-node/values.yaml

@@ -82,3 +82,8 @@ blockNode:
   secret:
     # if blank will use same as AppVersion of chart.
     PRIVATE_KEY: "fake_private_key"
+  health:
+    readiness:
+      endpoint: "/healthz/readiness"
+    liveness:
+      endpoint: "/healthz/liveness"

server/src/main/java/com/hedera/block/server/Server.java

@@ -21,6 +21,8 @@
 import com.hedera.block.server.config.BlockNodeContext;
 import com.hedera.block.server.config.BlockNodeContextFactory;
 import com.hedera.block.server.data.ObjectEvent;
+import com.hedera.block.server.health.HealthService;
+import com.hedera.block.server.health.HealthServiceImpl;
 import com.hedera.block.server.mediator.LiveStreamMediatorBuilder;
 import com.hedera.block.server.mediator.StreamMediator;
 import com.hedera.block.server.persistence.storage.PersistenceStorageConfig;
@@ -32,6 +34,7 @@
 import edu.umd.cs.findbugs.annotations.NonNull;
 import io.helidon.webserver.WebServer;
 import io.helidon.webserver.grpc.GrpcRouting;
+import io.helidon.webserver.http.HttpRouting;
 import java.io.IOException;
 
 /** Main class for the block node server */
@@ -82,16 +85,33 @@ public static void main(final String[] args) {
             final GrpcRouting.Builder grpcRouting =
                     GrpcRouting.builder().service(blockStreamService);
 
+            @NonNull final HealthService healthService = new HealthServiceImpl(serviceStatus);
+
+            @NonNull
+            final HttpRouting.Builder httpRouting =
+                    HttpRouting.builder()
+                            .register(healthService.getHealthRootPath(), healthService);
+
             // Build the web server
+            // TODO: make port server a configurable value.
             @NonNull
             final WebServer webServer =
-                    WebServer.builder().port(8080).addRouting(grpcRouting).build();
+                    WebServer.builder()
+                            .port(8080)
+                            .addRouting(grpcRouting)
+                            .addRouting(httpRouting)
+                            .build();
 
             // Update the serviceStatus with the web server
             serviceStatus.setWebServer(webServer);
 
             // Start the web server
             webServer.start();
+
+            // Log the server status
+            LOGGER.log(
+                    System.Logger.Level.INFO,
+                    "Block Node Server started at port: " + webServer.port());
         } catch (IOException e) {
             throw new RuntimeException(e);
         }

server/src/main/java/com/hedera/block/server/health/HealthService.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2024 Hedera Hashgraph, LLC
+ *
+ * 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 com.hedera.block.server.health;
+
+import edu.umd.cs.findbugs.annotations.NonNull;
+import io.helidon.webserver.http.HttpService;
+import io.helidon.webserver.http.ServerRequest;
+import io.helidon.webserver.http.ServerResponse;
+
+/** Defines the contract for health http service, needed for implementing an standard */
+public interface HealthService extends HttpService {
+    /**
+     * The path for the health group endpoints. Root path for all health endpoints.
+     *
+     * @return the root path for the health group endpoints
+     */
+    @NonNull
+    String getHealthRootPath();
+
+    /**
+     * Handles the request for liveness endpoint, that it most be defined on routing implementation.
+     *
+     * @param req the server request
+     * @param res the server response
+     */
+    void handleLiveness(@NonNull final ServerRequest req, @NonNull final ServerResponse res);
+
+    /**
+     * Handles the request for readiness endpoint, that it most be defined on routing
+     * implementation.
+     *
+     * @param req the server request
+     * @param res the server response
+     */
+    void handleReadiness(@NonNull final ServerRequest req, @NonNull final ServerResponse res);
+}

server/src/main/java/com/hedera/block/server/health/HealthServiceImpl.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2024 Hedera Hashgraph, LLC
+ *
+ * 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 com.hedera.block.server.health;
+
+import com.hedera.block.server.ServiceStatus;
+import edu.umd.cs.findbugs.annotations.NonNull;
+import io.helidon.webserver.http.HttpRules;
+import io.helidon.webserver.http.ServerRequest;
+import io.helidon.webserver.http.ServerResponse;
+
+/** Provides implementation for the health endpoints of the server. */
+public class HealthServiceImpl implements HealthService {
+
+    private static final String LIVENESS_PATH = "/liveness";
+    private static final String READINESS_PATH = "/readiness";
+
+    private final ServiceStatus serviceStatus;
+
+    /**
+     * It initializes the HealthService with needed dependencies.
+     *
+     * @param serviceStatus is used to check the status of the service
+     */
+    public HealthServiceImpl(@NonNull ServiceStatus serviceStatus) {
+        this.serviceStatus = serviceStatus;
+    }
+
+    @Override
+    @NonNull
+    public String getHealthRootPath() {
+        return "/healthz";
+    }
+
+    /**
+     * Configures the health routes for the server.
+     *
+     * @param httpRules is used to configure the health endpoints routes
+     */
+    @Override
+    public void routing(@NonNull final HttpRules httpRules) {
+        httpRules
+                .get(LIVENESS_PATH, this::handleLiveness)
+                .get(READINESS_PATH, this::handleReadiness);
+    }
+
+    /**
+     * Handles the request for liveness endpoint, that it most be defined on routing implementation.
+     *
+     * @param req the server request
+     * @param res the server response
+     */
+    @Override
+    public final void handleLiveness(
+            @NonNull final ServerRequest req, @NonNull final ServerResponse res) {
+        if (serviceStatus.isRunning()) {
+            res.status(200).send("OK");
+        } else {
+            res.status(503).send("Service is not running");
+        }
+    }
+
+    /**
+     * Handles the request for readiness endpoint, that it most be defined on routing
+     * implementation.
+     *
+     * @param req the server request
+     * @param res the server response
+     */
+    @Override
+    public final void handleReadiness(
+            @NonNull final ServerRequest req, @NonNull final ServerResponse res) {
+        if (serviceStatus.isRunning()) {
+            res.status(200).send("OK");
+        } else {
+            res.status(503).send("Service is not running");
+        }
+    }
+}

server/src/main/java/module-info.java

@@ -2,10 +2,8 @@
 
 /** Runtime module of the server. */
 module com.hedera.block.server {
-    exports com.hedera.block.server.consumer to
-            com.swirlds.config.impl;
-    exports com.hedera.block.server.persistence.storage to
-            com.swirlds.config.impl;
+    exports com.hedera.block.server.consumer;
+    exports com.hedera.block.server.persistence.storage;
 
     requires com.hedera.block.protos;
     requires com.google.protobuf;

server/src/test/java/com/hedera/block/server/health/HealthServiceTest.java

@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2024 Hedera Hashgraph, LLC
+ *
+ * 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 com.hedera.block.server.health;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.*;
+
+import com.hedera.block.server.ServiceStatus;
+import io.helidon.webserver.http.HttpRules;
+import io.helidon.webserver.http.ServerRequest;
+import io.helidon.webserver.http.ServerResponse;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@ExtendWith(MockitoExtension.class)
+class HealthServiceTest {
+
+    private static final String READINESS_PATH = "/readiness";
+    private static final String LIVENESS_PATH = "/liveness";
+    private static final String HEALTH_PATH = "/healthz";
+
+    @Mock private ServiceStatus serviceStatus;
+
+    @Mock ServerRequest serverRequest;
+
+    @Mock ServerResponse serverResponse;
+
+    @Test
+    public void testHandleLiveness() {
+        // given
+        when(serviceStatus.isRunning()).thenReturn(true);
+        when(serverResponse.status(200)).thenReturn(serverResponse);
+        doNothing().when(serverResponse).send("OK");
+        HealthService healthService = new HealthServiceImpl(serviceStatus);
+
+        // when
+        healthService.handleLiveness(serverRequest, serverResponse);
+
+        // then
+        verify(serverResponse, times(1)).status(200);
+        verify(serverResponse, times(1)).send("OK");
+    }
+
+    @Test
+    public void testHandleLiveness_notRunning() {
+        // given
+        when(serviceStatus.isRunning()).thenReturn(false);
+        when(serverResponse.status(503)).thenReturn(serverResponse);
+        doNothing().when(serverResponse).send("Service is not running");
+        HealthService healthService = new HealthServiceImpl(serviceStatus);
+
+        // when
+        healthService.handleLiveness(serverRequest, serverResponse);
+
+        // then
+        verify(serverResponse, times(1)).status(503);
+        verify(serverResponse, times(1)).send("Service is not running");
+    }
+
+    @Test
+    public void testHandleReadiness() {
+        // given
+        when(serviceStatus.isRunning()).thenReturn(true);
+        when(serverResponse.status(200)).thenReturn(serverResponse);
+        doNothing().when(serverResponse).send("OK");
+        HealthService healthService = new HealthServiceImpl(serviceStatus);
+
+        // when
+        healthService.handleReadiness(serverRequest, serverResponse);
+
+        // then
+        verify(serverResponse, times(1)).status(200);
+        verify(serverResponse, times(1)).send("OK");
+    }
+
+    @Test
+    public void testHandleReadiness_notRunning() {
+        // given
+        when(serviceStatus.isRunning()).thenReturn(false);
+        when(serverResponse.status(503)).thenReturn(serverResponse);
+        doNothing().when(serverResponse).send("Service is not running");
+        HealthService healthService = new HealthServiceImpl(serviceStatus);
+
+        // when
+        healthService.handleReadiness(serverRequest, serverResponse);
+
+        // then
+        verify(serverResponse, times(1)).status(503);
+        verify(serverResponse, times(1)).send("Service is not running");
+    }
+
+    @Test
+    public void testRouting() {
+        // given
+        HealthService healthService = new HealthServiceImpl(serviceStatus);
+        HttpRules httpRules = mock(HttpRules.class);
+        when(httpRules.get(anyString(), any())).thenReturn(httpRules);
+
+        // when
+        healthService.routing(httpRules);
+
+        // then
+        verify(httpRules, times(1)).get(eq(LIVENESS_PATH), any());
+        verify(httpRules, times(1)).get(eq(READINESS_PATH), any());
+        assertEquals(HEALTH_PATH, healthService.getHealthRootPath());
+    }
+}