Examples: Add a JWT authentication example

RELEASING.md

@@ -46,6 +46,8 @@ $ VERSION_FILES=(
   examples/example-alts/build.gradle
   examples/example-gauth/build.gradle
   examples/example-gauth/pom.xml
+  examples/example-jwt-auth/build.gradle
+  examples/example-jwt-auth/pom.xml
   examples/example-kotlin/build.gradle
   examples/example-kotlin/android/helloworld/app/build.gradle
   examples/example-tls/build.gradle

examples/README.md

@@ -159,6 +159,8 @@ $ bazel-bin/hello-world-client
 
 - [Google Authentication](example-gauth)
 
+- [JWT-based Authentication](example-jwt-auth)
+
 - [Kotlin examples](example-kotlin)
 
 - [Kotlin Android examples](example-kotlin/android)

examples/example-jwt-auth/README.md

@@ -0,0 +1,65 @@
+Authentication Example
+==============================================
+
+This example illustrates a simple JWT-based authentication implementation in gRPC using
+ server interceptor. It uses the JJWT library to create and verify JSON Web Tokens (JWTs).
+
+The example requires grpc-java to be pre-built. Using a release tag will download the relevant binaries
+from a maven repository. But if you need the latest SNAPSHOT binaries you will need to follow
+[COMPILING](../../COMPILING.md) to build these.
+
+The source code is [here](src/main/java/io/grpc/examples/jwtauth). Please follow the
+[steps](../README.md#-to-build-the-examples) to build the examples. The build creates scripts
+`auth-server` and `auth-client` in the `build/install/examples/bin/` directory which can be
+used to run this example. The example requires the server to be running before starting the
+client.
+
+Running auth-server is similar to the normal hello world example and there are no arguments to supply:
+
+**auth-server**:
+
+```text
+USAGE: AuthServer
+```
+
+The auth-client accepts optional arguments for user-name and client-id:
+
+**auth-client**:
+
+```text
+USAGE: AuthClient [user-name [client-id]]
+```
+
+The `user-name` value is simply passed in the `HelloRequest` message as payload and the value of
+`client-id` is included in the JWT claims passed in the metadata header.
+
+
+#### How to run the example:
+
+```bash
+# Run the server:
+./build/install/example-jwt-auth/bin/auth-server
+# In another terminal run the client
+./build/install/example-jwt-auth/bin/auth-client userA clientB
+```
+
+That's it! The client will show the user-name reflected back in the message from the server as follows:
+```
+INFO: Greeting: Hello, userA
+```
+
+And on the server side you will see the message with the client's identifier:
+```
+Processing request from clientB
+```
+
+## Maven
+
+If you prefer to use Maven follow these [steps](../README.md#maven). You can run the example as follows:
+
+```
+$ # Run the server
+$ mvn exec:java -Dexec.mainClass=io.grpc.examples.authentication.AuthServer
+$ # In another terminal run the client
+$ mvn exec:java -Dexec.mainClass=io.grpc.examples.authentication.AuthClient -Dexec.args="userA clientB"
+```

examples/example-jwt-auth/build.gradle

@@ -0,0 +1,84 @@
+plugins {
+    // Provide convenience executables for trying out the examples.
+    id 'application'
+    // ASSUMES GRADLE 2.12 OR HIGHER. Use plugin version 0.7.5 with earlier gradle versions
+    id 'com.google.protobuf' version '0.8.8'
+    // Generate IntelliJ IDEA's .idea & .iml project files
+    id 'idea'
+}
+
+repositories {
+    maven { // The google mirror is less flaky than mavenCentral()
+        url "https://maven-central.storage-download.googleapis.com/repos/central/data/"
+    }
+    mavenLocal()
+}
+
+sourceCompatibility = 1.7
+targetCompatibility = 1.7
+
+// IMPORTANT: You probably want the non-SNAPSHOT version of gRPC. Make sure you
+// are looking at a tagged version of the example and not "master"!
+
+// Feel free to delete the comment at the next line. It is just for safely
+// updating the version in our release process.
+def grpcVersion = '1.23.0-SNAPSHOT' // CURRENT_GRPC_VERSION
+def protobufVersion = '3.7.1'
+def protocVersion = protobufVersion
+
+dependencies {
+    implementation "io.grpc:grpc-protobuf:${grpcVersion}"
+    implementation "io.grpc:grpc-stub:${grpcVersion}"
+    implementation "io.jsonwebtoken:jjwt:0.9.1"
+    implementation "javax.xml.bind:jaxb-api:2.3.1"
+
+    compileOnly "javax.annotation:javax.annotation-api:1.2"
+
+    runtimeOnly "io.grpc:grpc-netty-shaded:${grpcVersion}"
+
+    testImplementation "io.grpc:grpc-testing:${grpcVersion}"
+    testImplementation "junit:junit:4.12"
+    testImplementation "org.mockito:mockito-core:2.25.1"
+}
+
+protobuf {
+    protoc { artifact = "com.google.protobuf:protoc:${protocVersion}" }
+    plugins {
+        grpc { artifact = "io.grpc:protoc-gen-grpc-java:${grpcVersion}" }
+    }
+    generateProtoTasks {
+        all()*.plugins { grpc {} }
+    }
+}
+
+// Inform IDEs like IntelliJ IDEA, Eclipse or NetBeans about the generated code.
+sourceSets {
+    main {
+        java {
+            srcDirs 'build/generated/source/proto/main/grpc'
+            srcDirs 'build/generated/source/proto/main/java'
+        }
+    }
+}
+
+startScripts.enabled = false
+
+task authServer(type: CreateStartScripts) {
+    mainClassName = 'io.grpc.examples.authentication.AuthServer'
+    applicationName = 'auth-server'
+    outputDir = new File(project.buildDir, 'tmp')
+    classpath = startScripts.classpath
+}
+
+task authClient(type: CreateStartScripts) {
+    mainClassName = 'io.grpc.examples.authentication.AuthClient'
+    applicationName = 'auth-client'
+    outputDir = new File(project.buildDir, 'tmp')
+    classpath = startScripts.classpath
+}
+
+applicationDistribution.into('bin') {
+    from(authServer)
+    from(authClient)
+    fileMode = 0755
+}

examples/example-jwt-auth/pom.xml

@@ -0,0 +1,136 @@
+<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>
+  <groupId>io.grpc</groupId>
+  <artifactId>example-jwt-auth</artifactId>
+  <packaging>jar</packaging>
+  <!-- Feel free to delete the comment at the end of these lines. It is just
+       for safely updating the version in our release process. -->
+  <version>1.23.0-SNAPSHOT</version><!-- CURRENT_GRPC_VERSION -->
+  <name>example-jwt-auth</name>
+  <url>https://github.com/grpc/grpc-java</url>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <grpc.version>1.23.0-SNAPSHOT</grpc.version><!-- CURRENT_GRPC_VERSION -->
+    <protobuf.version>3.7.1</protobuf.version>
+    <protoc.version>3.7.1</protoc.version>
+    <!-- required for jdk9 -->
+    <maven.compiler.source>1.7</maven.compiler.source>
+    <maven.compiler.target>1.7</maven.compiler.target>
+  </properties>
+
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>io.grpc</groupId>
+        <artifactId>grpc-bom</artifactId>
+        <version>${grpc.version}</version>
+        <type>pom</type>
+        <scope>import</scope>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
+
+  <dependencies>
+    <dependency>
+      <groupId>io.grpc</groupId>
+      <artifactId>grpc-netty-shaded</artifactId>
+      <scope>runtime</scope>
+    </dependency>
+    <dependency>
+      <groupId>io.grpc</groupId>
+      <artifactId>grpc-protobuf</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>io.grpc</groupId>
+      <artifactId>grpc-stub</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>io.jsonwebtoken</groupId>
+      <artifactId>jjwt</artifactId>
+      <version>0.9.1</version>
+    </dependency>
+    <dependency>
+      <groupId>javax.xml.bind</groupId>
+      <artifactId>jaxb-api</artifactId>
+      <version>2.3.1</version>
+    </dependency>
+    <dependency>
+      <groupId>javax.annotation</groupId>
+      <artifactId>javax.annotation-api</artifactId>
+      <version>1.2</version>
+      <scope>provided</scope> <!-- not needed at runtime -->
+    </dependency>
+    <dependency>
+      <groupId>io.grpc</groupId>
+      <artifactId>grpc-testing</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.12</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <version>2.25.1</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <extensions>
+      <extension>
+        <groupId>kr.motd.maven</groupId>
+        <artifactId>os-maven-plugin</artifactId>
+        <version>1.5.0.Final</version>
+      </extension>
+    </extensions>
+    <plugins>
+      <plugin>
+        <groupId>org.xolstice.maven.plugins</groupId>
+        <artifactId>protobuf-maven-plugin</artifactId>
+        <version>0.5.1</version>
+        <configuration>
+          <protocArtifact>
+            com.google.protobuf:protoc:${protoc.version}:exe:${os.detected.classifier}
+          </protocArtifact>
+          <pluginId>grpc-java</pluginId>
+          <pluginArtifact>
+            io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}
+          </pluginArtifact>
+        </configuration>
+        <executions>
+          <execution>
+            <goals>
+              <goal>compile</goal>
+              <goal>compile-custom</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-enforcer-plugin</artifactId>
+        <version>1.4.1</version>
+        <executions>
+          <execution>
+            <id>enforce</id>
+            <goals>
+              <goal>enforce</goal>
+            </goals>
+            <configuration>
+              <rules>
+                <requireUpperBoundDeps/>
+              </rules>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>

examples/example-jwt-auth/settings.gradle

@@ -0,0 +1,8 @@
+pluginManagement {
+    repositories {
+        maven { // The google mirror is less flaky than mavenCentral()
+            url "https://maven-central.storage-download.googleapis.com/repos/central/data/"
+        }
+        gradlePluginPortal()
+    }
+}