Merge gateway to services (#840)

pom.xml

@@ -1,5 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
   <modelVersion>4.0.0</modelVersion>
 
   <parent>
@@ -85,6 +87,7 @@
     <module>services</module>
     <module>services-api</module>
     <module>services-transport-parent</module>
+    <module>services-gateway</module>
     <module>services-discovery</module>
     <module>services-security</module>
     <module>services-examples</module>

services-api/pom.xml

@@ -1,5 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 
   <modelVersion>4.0.0</modelVersion>
 

services-discovery/pom.xml

@@ -1,4 +1,6 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
 
   <parent>

services-examples/pom.xml

@@ -1,5 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
   <modelVersion>4.0.0</modelVersion>
 
   <parent>

services-examples/src/main/java/io/scalecube/services/examples/gateway/HttpGatewayExample.java

@@ -0,0 +1,51 @@
+package io.scalecube.services.examples.gateway;
+
+import io.scalecube.net.Address;
+import io.scalecube.services.gateway.Gateway;
+import io.scalecube.services.gateway.GatewayOptions;
+import java.net.InetSocketAddress;
+import java.time.Duration;
+import java.util.concurrent.ThreadLocalRandom;
+import reactor.core.publisher.Mono;
+
+public class HttpGatewayExample implements Gateway {
+
+  private final GatewayOptions options;
+  private final InetSocketAddress address;
+
+  public HttpGatewayExample(GatewayOptions options) {
+    this.options = options;
+    this.address = new InetSocketAddress(options.port());
+  }
+
+  @Override
+  public String id() {
+    return options.id();
+  }
+
+  @Override
+  public Address address() {
+    return Address.create(address.getHostString(), address.getPort());
+  }
+
+  @Override
+  public Mono<Gateway> start() {
+    return Mono.defer(
+        () -> {
+          System.out.println("Starting HTTP gateway...");
+
+          return Mono.delay(Duration.ofMillis(ThreadLocalRandom.current().nextInt(100, 500)))
+              .map(tick -> this)
+              .doOnSuccess(gw -> System.out.println("HTTP gateway is started on " + gw.address));
+        });
+  }
+
+  @Override
+  public Mono<Void> stop() {
+    return Mono.defer(
+        () -> {
+          System.out.println("Stopping HTTP gateway...");
+          return Mono.empty();
+        });
+  }
+}

services-examples/src/main/java/io/scalecube/services/examples/gateway/WebsocketGatewayExample.java

@@ -0,0 +1,51 @@
+package io.scalecube.services.examples.gateway;
+
+import io.scalecube.net.Address;
+import io.scalecube.services.gateway.Gateway;
+import io.scalecube.services.gateway.GatewayOptions;
+import java.net.InetSocketAddress;
+import java.time.Duration;
+import java.util.concurrent.ThreadLocalRandom;
+import reactor.core.publisher.Mono;
+
+public class WebsocketGatewayExample implements Gateway {
+
+  private final GatewayOptions options;
+  private final InetSocketAddress address;
+
+  public WebsocketGatewayExample(GatewayOptions options) {
+    this.options = options;
+    this.address = new InetSocketAddress(options.port());
+  }
+
+  @Override
+  public String id() {
+    return options.id();
+  }
+
+  @Override
+  public Address address() {
+    return Address.create(address.getHostString(), address.getPort());
+  }
+
+  @Override
+  public Mono<Gateway> start() {
+    return Mono.defer(
+        () -> {
+          System.out.println("Starting WS gateway...");
+
+          return Mono.delay(Duration.ofMillis(ThreadLocalRandom.current().nextInt(100, 500)))
+              .map(tick -> this)
+              .doOnSuccess(gw -> System.out.println("WS gateway is started on " + gw.address));
+        });
+  }
+
+  @Override
+  public Mono<Void> stop() {
+    return Mono.defer(
+        () -> {
+          System.out.println("Stopping WS gateway...");
+          return Mono.empty();
+        });
+  }
+}

services-gateway/pom.xml

@@ -0,0 +1,92 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>io.scalecube</groupId>
+    <artifactId>scalecube-services-parent</artifactId>
+    <version>2.10.26-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>services-gateway</artifactId>
+  <packaging>jar</packaging>
+
+  <dependencies>
+    <dependency>
+      <groupId>io.scalecube</groupId>
+      <artifactId>scalecube-services</artifactId>
+      <version>${project.parent.version}</version>
+    </dependency>
+
+    <dependency>
+      <groupId>io.projectreactor.netty</groupId>
+      <artifactId>reactor-netty</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>com.fasterxml.jackson.datatype</groupId>
+      <artifactId>jackson-datatype-jsr310</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-core</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>org.jctools</groupId>
+      <artifactId>jctools-core</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+    </dependency>
+
+    <!-- Tests -->
+    <dependency>
+      <groupId>io.scalecube</groupId>
+      <artifactId>scalecube-services-examples</artifactId>
+      <version>${project.parent.version}</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>io.scalecube</groupId>
+      <artifactId>scalecube-services-discovery</artifactId>
+      <version>${project.parent.version}</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>io.scalecube</groupId>
+      <artifactId>scalecube-services-transport-rsocket</artifactId>
+      <version>${project.parent.version}</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>io.scalecube</groupId>
+      <artifactId>scalecube-services-transport-jackson</artifactId>
+      <version>${project.parent.version}</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-slf4j-impl</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-core</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>com.lmax</groupId>
+      <artifactId>disruptor</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+</project>

services-gateway/src/main/java/io/scalecube/services/gateway/GatewaySession.java

@@ -0,0 +1,20 @@
+package io.scalecube.services.gateway;
+
+import java.util.Map;
+
+public interface GatewaySession {
+
+  /**
+   * Session id representation to be unique per client session.
+   *
+   * @return session id
+   */
+  long sessionId();
+
+  /**
+   * Returns headers associated with session.
+   *
+   * @return headers map
+   */
+  Map<String, String> headers();
+}

services-gateway/src/main/java/io/scalecube/services/gateway/GatewaySessionHandler.java

@@ -0,0 +1,110 @@
+package io.scalecube.services.gateway;
+
+import io.netty.buffer.ByteBuf;
+import io.scalecube.services.api.ServiceMessage;
+import java.util.Map;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Mono;
+import reactor.util.context.Context;
+
+public interface GatewaySessionHandler {
+
+  Logger LOGGER = LoggerFactory.getLogger(GatewaySessionHandler.class);
+
+  GatewaySessionHandler DEFAULT_INSTANCE = new GatewaySessionHandler() {};
+
+  /**
+   * Message mapper function.
+   *
+   * @param session webscoket session (not null)
+   * @param message request message (not null)
+   * @return message
+   */
+  default ServiceMessage mapMessage(
+      GatewaySession session, ServiceMessage message, Context context) {
+    return message;
+  }
+
+  /**
+   * Request mapper function.
+   *
+   * @param session session
+   * @param byteBuf request buffer
+   * @param context subscriber context
+   * @return context
+   */
+  default Context onRequest(GatewaySession session, ByteBuf byteBuf, Context context) {
+    return context;
+  }
+
+  /**
+   * On response handler.
+   *
+   * @param session session
+   * @param byteBuf response buffer
+   * @param message response message
+   * @param context subscriber context
+   */
+  default void onResponse(
+      GatewaySession session, ByteBuf byteBuf, ServiceMessage message, Context context) {
+    // no-op
+  }
+
+  /**
+   * Error handler function.
+   *
+   * @param session webscoket session (not null)
+   * @param throwable an exception that occurred (not null)
+   * @param context subscriber context
+   */
+  default void onError(GatewaySession session, Throwable throwable, Context context) {
+    LOGGER.error(
+        "Exception occurred on session: {}, on context: {}, cause:",
+        session.sessionId(),
+        context,
+        throwable);
+  }
+
+  /**
+   * Error handler function.
+   *
+   * @param session webscoket session (not null)
+   * @param throwable an exception that occurred (not null)
+   */
+  default void onSessionError(GatewaySession session, Throwable throwable) {
+    LOGGER.error("Exception occurred on session: {}, cause:", session.sessionId(), throwable);
+  }
+
+  /**
+   * On connection open handler.
+   *
+   * @param sessionId session id
+   * @param headers connection/session headers
+   * @return mono result
+   */
+  default Mono<Void> onConnectionOpen(long sessionId, Map<String, String> headers) {
+    return Mono.fromRunnable(
+        () ->
+            LOGGER.debug(
+                "Connection opened, sessionId: {}, headers({})", sessionId, headers.size()));
+  }
+
+  /**
+   * On session open handler.
+   *
+   * @param session websocket session (not null)
+   */
+  default void onSessionOpen(GatewaySession session) {
+    LOGGER.info("Session opened: {}", session);
+  }
+
+  /**
+   * On session close handler.
+   *
+   * @param session websocket session (not null)
+   */
+  default void onSessionClose(GatewaySession session) {
+    LOGGER.info("Session closed: {}", session);
+  }
+}