feat(webhook): WebHook Listener Microservice & Receiver Setup

.gitignore

@@ -172,4 +172,6 @@ install_manifest.txt
 compile_commands.json
 CTestTestfile.cmake
 _deps
-CMakeUserPresets.json
+CMakeUserPresets.json
+
+.DS_STORE

server/application-server/.env.example

@@ -1,3 +1,7 @@
 DATASOURCE_URL=jdbc:postgresql://127.0.0.1/helios
 DATASOURCE_USERNAME=helios
-DATASOURCE_PASSWORD=helios
+DATASOURCE_PASSWORD=helios
+NATS_SERVER=localhost:4222
+NATS_AUTH_TOKEN='5760e8ae09adfb2756f9f8cd5cb2caa704cd3f549eaa9298be843ceb165185d815b81f90c680fa7f626b7cd63abf6ac9'
+REPOSITORY_NAME=<repository_name e.g. ls1intum/Helios>
+

server/application-server/.gitignore

@@ -37,3 +37,5 @@ out/
 ### VS Code ###
 .vscode/
 .sdkmanrc
+
+.DS_STORE

server/application-server/README.md

@@ -28,7 +28,7 @@ $ ./gradlew build
 
 **3. Setup configuration and environment**
 
-Copy the file `.env.example` to `.env` and adjust the values to your needs. It is automatically set up to work with the Docker Compose setup.
+Copy the file `.env.example` to `.env` and adjust the values to your needs. It is set up to work with the Docker Compose setup for database. You need to adjust some fields for NATS server.
 
 ```bash
 $ cp .env.example .env

server/application-server/build.gradle

@@ -1,24 +1,24 @@
 plugins {
-	id 'java'
-	id 'war'
-	id 'org.springframework.boot' version '3.3.4'
-	id 'io.spring.dependency-management' version '1.1.6'
-	id 'io.freefair.lombok' version '8.10.2'
-	id 'org.springdoc.openapi-gradle-plugin' version '1.9.0'
-	id 'org.openapi.generator' version '6.6.0'
+    id 'java'
+    id 'war'
+    id 'org.springframework.boot' version '3.3.4'
+    id 'io.spring.dependency-management' version '1.1.6'
+    id 'io.freefair.lombok' version '8.10.2'
+    id 'org.springdoc.openapi-gradle-plugin' version '1.9.0'
+    id 'org.openapi.generator' version '6.6.0'
 }
 
 group = 'de.tum.cit.aet'
 version = '0.0.1-SNAPSHOT'
 
 java {
-	toolchain {
-		languageVersion = JavaLanguageVersion.of(22)
-	}
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(22)
+    }
 }
 
 repositories {
-	mavenCentral()
+    mavenCentral()
 }
 
 def loadEnvFile() {
@@ -48,27 +48,29 @@ def loadEnvFile() {
 
 
 dependencies {
-	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
-	implementation 'org.springframework.boot:spring-boot-starter-web'
-	implementation 'org.springdoc:springdoc-openapi-starter-webmvc-ui:2.6.0'
-	implementation 'org.openapitools:jackson-databind-nullable:0.2.6'
-	runtimeOnly 'org.postgresql:postgresql'
-	providedRuntime 'org.springframework.boot:spring-boot-starter-tomcat'
-	testImplementation 'org.springframework.boot:spring-boot-starter-test'
-	testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
+    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
+    implementation 'org.springframework.boot:spring-boot-starter-web'
+    implementation 'org.springdoc:springdoc-openapi-starter-webmvc-ui:2.6.0'
+    implementation 'org.openapitools:jackson-databind-nullable:0.2.6'
+    implementation 'io.nats:jnats:2.20.4'
+    implementation 'org.kohsuke:github-api:1.326'
+    runtimeOnly 'org.postgresql:postgresql'
+    providedRuntime 'org.springframework.boot:spring-boot-starter-tomcat'
+    testImplementation 'org.springframework.boot:spring-boot-starter-test'
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
 }
 
 tasks.named('test') {
-	useJUnitPlatform()
+    useJUnitPlatform()
 }
 
 openApi {
     apiDocsUrl = 'http://localhost:8080/v3/api-docs.yaml'
     outputDir = file('.')
     outputFileName = 'openapi.yaml'
-	def envVars = loadEnvFile()
-	customBootRun {
-		args.set(["--spring.profiles.active=dev", "--DATASOURCE_URL=${envVars['DATASOURCE_URL'] ?: ''}", "--DATASOURCE_USERNAME=${envVars['DATASOURCE_USERNAME'] ?: ''}", "--DATASOURCE_PASSWORD=${envVars['DATASOURCE_PASSWORD'] ?: ''}"])
-	}
+    def envVars = loadEnvFile()
+    customBootRun {
+        args.set(["--spring.profiles.active=dev", "--DATASOURCE_URL=${envVars['DATASOURCE_URL'] ?: ''}", "--DATASOURCE_USERNAME=${envVars['DATASOURCE_USERNAME'] ?: ''}", "--DATASOURCE_PASSWORD=${envVars['DATASOURCE_PASSWORD'] ?: ''}"])
+    }
 
 }

server/application-server/src/main/java/de/tum/cit/aet/helios/config/NatsConfig.java

@@ -0,0 +1,28 @@
+package de.tum.cit.aet.helios.config;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
+
+import io.nats.client.Connection;
+import io.nats.client.Nats;
+import io.nats.client.Options;
+
+@Configuration
+public class NatsConfig {
+
+    @Value("${nats.server}")
+    private String natsServer;
+
+    @Value("${nats.auth.token}")
+    private String natsAuthToken;
+
+    @Bean
+    public Connection natsConnection() throws Exception {
+
+        Options options = Options.builder().server(natsServer).token(natsAuthToken).build();
+        return Nats.connect(options);
+    }
+}

server/application-server/src/main/java/de/tum/cit/aet/helios/gitprovider/common/github/GitHubMessageHandler.java

@@ -0,0 +1,62 @@
+package de.tum.cit.aet.helios.gitprovider.common.github;
+
+import java.io.IOException;
+import java.io.StringReader;
+import java.nio.charset.StandardCharsets;
+
+import org.kohsuke.github.GHEvent;
+import org.kohsuke.github.GHEventPayload;
+import org.kohsuke.github.GitHub;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import io.nats.client.Message;
+import io.nats.client.MessageHandler;
+import org.springframework.stereotype.Component;
+
+@Component
+public abstract class GitHubMessageHandler<T extends GHEventPayload> implements MessageHandler {
+
+    private static final Logger logger = LoggerFactory.getLogger(GitHubMessageHandler.class);
+
+    private final Class<T> payloadType;
+
+    protected GitHubMessageHandler(Class<T> payloadType) {
+        this.payloadType = payloadType;
+    }
+
+    @Override
+    public void onMessage(Message msg) {
+        String eventType = getHandlerEvent().name().toLowerCase();
+        String subject = msg.getSubject();
+        if (!subject.endsWith(eventType)) {
+            logger.error("Received message on unexpected subject: {}, expected to end with {}", subject, eventType);
+            return;
+        }
+
+        String payload = new String(msg.getData(), StandardCharsets.UTF_8);
+
+        try (StringReader reader = new StringReader(payload)) {
+            T eventPayload = GitHub.offline().parseEventPayload(reader, payloadType);
+            handleEvent(eventPayload);
+        } catch (IOException e) {
+            logger.error("Failed to parse payload for subject {}: {}", subject, e.getMessage(), e);
+        } catch (Exception e) {
+            logger.error("Unexpected error while handling message for subject {}: {}", subject, e.getMessage(), e);
+        }
+    }
+
+    /**
+     * Handles the parsed event payload.
+     *
+     * @param eventPayload The parsed GHEventPayload.
+     */
+    protected abstract void handleEvent(T eventPayload);
+
+    /**
+     * Returns the GHEvent that this handler is responsible for.
+     *
+     * @return The GHEvent.
+     */
+    protected abstract GHEvent getHandlerEvent();
+}

server/application-server/src/main/java/de/tum/cit/aet/helios/gitprovider/common/github/GitHubMessageHandlerRegistry.java

@@ -0,0 +1,29 @@
+package de.tum.cit.aet.helios.gitprovider.common.github;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.kohsuke.github.GHEvent;
+import org.springframework.stereotype.Component;
+
+@Component
+public class GitHubMessageHandlerRegistry {
+
+    private final Map<GHEvent, GitHubMessageHandler<?>> handlerMap = new HashMap<>();
+
+    public GitHubMessageHandlerRegistry(GitHubMessageHandler<?>[] handlers) {
+        for (GitHubMessageHandler<?> handler : handlers) {
+            handlerMap.put(handler.getHandlerEvent(), handler);
+        }
+    }
+
+    public GitHubMessageHandler<?> getHandler(GHEvent eventType) {
+        return handlerMap.get(eventType);
+    }
+
+    public List<GHEvent> getSupportedEvents() {
+        return new ArrayList<>(handlerMap.keySet());
+    }
+}

server/application-server/src/main/java/de/tum/cit/aet/helios/gitprovider/issue/github/GitHubIssueMessageHandler.java

@@ -0,0 +1,35 @@
+package de.tum.cit.aet.helios.gitprovider.issue.github;
+
+import org.kohsuke.github.GHEvent;
+import org.kohsuke.github.GHEventPayload;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import de.tum.cit.aet.helios.gitprovider.common.github.GitHubMessageHandler;
+
+@Component
+public class GitHubIssueMessageHandler extends GitHubMessageHandler<GHEventPayload.Issue> {
+
+    private static final Logger logger = LoggerFactory.getLogger(GitHubIssueMessageHandler.class);    
+
+    private GitHubIssueMessageHandler() {
+        super(GHEventPayload.Issue.class);
+    }
+
+    @Override
+    protected void handleEvent(GHEventPayload.Issue eventPayload) {
+        var action = eventPayload.getAction();
+        var repository = eventPayload.getRepository();
+        var issue = eventPayload.getIssue();
+        logger.info("Received issue event for repository: {}, issue: {}, action: {}",
+                repository.getFullName(),
+                issue.getNumber(),
+                action);    
+    }
+
+    @Override
+    protected GHEvent getHandlerEvent() {
+        return GHEvent.ISSUES;
+    }
+}