Refactor deployer app so that it starts empty

Functions are namespaced under the "app name", e.g.
/sample/uppercase is the "uppercase" function in the "sample" app.

Also added a README to get started quickly.

spring-cloud-function-deployer/README.md

@@ -0,0 +1,56 @@
+Spring Cloud Function Deployer is an app that can deploy functions packaged as jars. Once the app is running it can deploy a basic Spring Cloud Function app from a jar with locally cached dependencies in about 500ms (compared to 1500ms for the same application launched from cold). It can be used in a pool as a "warm" JVM to deploy functions quicker than they could be started from scratch.
+
+The app has a single endpoint called "/admin" that you can use to manage the deployed functions. You GET from it to list the deployed apps, POST to `/{name}` to deploy a named app with a `path` parameter pointing to a jar resource, and then DELETE `/{name}` to remove it. Functions in the apps are exposed as `/{name}/{function}` with the usual conventions for Spring Cloud Function (i.e. the function name is the bean name by default).
+
+== Running the Deployer
+
+Run the main class `ApplicationRunner` in this project (from the command line or in the IDE). E.g.
+
+```
+$ ./mvnw install -DskipTests
+$ cd spring-cloud-function-deployer
+$ ../mvnw spring-boot:run
+```
+
+The app starts empty, so the admin resource shows no deployed apps:
+
+```
+$ curl localhost:8080/admin
+{}
+```
+
+Deploy a sample like this:
+
+```
+$ curl localhost:8080/admin/pojos -d path=maven://com.example:function-sample-pojo:1.0.0.BUILD-SNAPSHOT
+{"id":"81c568e36c7909ec1dd841aa7ee6d3e3"}
+```
+
+(takes about 500ms, once the local Maven cache is warm). Deploy another one:
+
+```
+$ curl localhost:8080/admin/sample -d path=maven://com.example:function-sample:1.0.0.BUILD-SNAPSHOT
+{"id":"cb2fdb3130f6349f143f4686848ea90f"}
+```
+
+Undeploy the first one:
+
+```
+$ curl localhost:8080/admin/pojos -X DELETE
+{"name":"81c568e36c7909ec1dd841aa7ee6d3e3","id":"pojos","path":"maven://com.example:function-sample-pojo:1.0.0.BUILD-SNAPSHOT"}
+```
+
+List the deployed apps:
+
+```
+$ curl localhost:8080/admin
+{"sample":{"name":"sample","id":"cb2fdb3130f6349f143f4686848ea90","path":"maven://com.example:function-sample:1.0.0.BUILD-SNAPSHOT"}}
+```
+
+Send an event to one of the functions:
+
+```
+$ curl -H "Content-Type: text/plain" localhost:8080/sample/uppercase -d foo
+FOO
+```
+

spring-cloud-function-deployer/src/main/java/org/springframework/cloud/function/deployer/FunctionAdminController.java

@@ -15,19 +15,10 @@
  */
 package org.springframework.cloud.function.deployer;
 
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.Map;
 
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.boot.CommandLineRunner;
-import org.springframework.boot.loader.thin.ArchiveUtils;
-import org.springframework.cloud.deployer.spi.app.AppDeployer;
-import org.springframework.cloud.deployer.spi.core.AppDefinition;
-import org.springframework.cloud.deployer.spi.core.AppDeploymentRequest;
-import org.springframework.context.support.LiveBeansView;
-import org.springframework.core.io.FileSystemResource;
-import org.springframework.core.io.Resource;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -42,7 +33,7 @@ import org.springframework.web.bind.annotation.RestController;
  */
 @RestController
 @RequestMapping("/admin")
-public class FunctionAdminController implements CommandLineRunner {
+public class FunctionAdminController {
 
 	private final FunctionExtractingFunctionCatalog deployer;
 
@@ -68,21 +59,8 @@ public class FunctionAdminController implements CommandLineRunner {
 		return deployer.deployed();
 	}
 
-	@Override
-	public void run(String... args) throws Exception {
-		deploy("sample", "maven://com.example:function-sample-pojo:1.0.0.BUILD-SNAPSHOT");
-	}
-
 	private String deploy(String name, String path, String... args) throws Exception {
-		Resource resource = new FileSystemResource(
-				ArchiveUtils.getArchiveRoot(ArchiveUtils.getArchive(path)));
-		AppDefinition definition = new AppDefinition(resource.getFilename(),
-				Collections.singletonMap(LiveBeansView.MBEAN_DOMAIN_PROPERTY_NAME,
-						"functions." + name));
-		AppDeploymentRequest request = new AppDeploymentRequest(definition, resource,
-				Collections.singletonMap(AppDeployer.GROUP_PROPERTY_KEY, "functions"),
-				Arrays.asList(args));
-		String deployed = deployer.deploy(name, request);
+		String deployed = deployer.deploy(name, path, args);
 		return deployed;
 	}
 }

spring-cloud-function-deployer/src/main/java/org/springframework/cloud/function/deployer/FunctionExtractingFunctionCatalog.java

@@ -15,8 +15,11 @@
  */
 package org.springframework.cloud.function.deployer;
 
-import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Consumer;
@@ -26,10 +29,16 @@ import java.util.function.Supplier;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.boot.loader.thin.ArchiveUtils;
+import org.springframework.cloud.deployer.spi.app.AppDeployer;
+import org.springframework.cloud.deployer.spi.core.AppDefinition;
 import org.springframework.cloud.deployer.spi.core.AppDeploymentRequest;
 import org.springframework.cloud.deployer.thin.ThinJarAppDeployer;
 import org.springframework.cloud.function.context.FunctionInspector;
 import org.springframework.cloud.function.registry.FunctionCatalog;
+import org.springframework.context.support.LiveBeansView;
+import org.springframework.core.io.FileSystemResource;
+import org.springframework.core.io.Resource;
 import org.springframework.util.MethodInvoker;
 
 public class FunctionExtractingFunctionCatalog
@@ -44,6 +53,8 @@ public class FunctionExtractingFunctionCatalog
 
 	private Map<String, String> names = new LinkedHashMap<>();
 
+	private Map<String, String> ids = new LinkedHashMap<>();
+
 	public FunctionExtractingFunctionCatalog() {
 		this("thin", "slim");
 	}
@@ -123,15 +134,19 @@ public class FunctionExtractingFunctionCatalog
 		return (String) inspect(function, "getName");
 	}
 
-	public String deploy(String name, AppDeploymentRequest request) {
+	public String deploy(String name, String path, String... args) {
+		Resource resource = new FileSystemResource(
+				ArchiveUtils.getArchiveRoot(ArchiveUtils.getArchive(path)));
+		AppDefinition definition = new AppDefinition(resource.getFilename(),
+				Collections.singletonMap(LiveBeansView.MBEAN_DOMAIN_PROPERTY_NAME,
+						"functions." + name));
+		AppDeploymentRequest request = new AppDeploymentRequest(definition, resource,
+				Collections.singletonMap(AppDeployer.GROUP_PROPERTY_KEY, "functions"),
+				Arrays.asList(args));
 		String id = this.deployer.deploy(request);
-		try {
-			this.deployed.put(id, request.getResource().getURI().toString());
-		}
-		catch (IOException e) {
-			throw new IllegalStateException("Cannot locate resource for " + name, e);
-		}
+		this.deployed.put(id, path);
 		this.names.put(name, id);
+		this.ids.put(id, name);
 		return id;
 	}
 
@@ -142,10 +157,10 @@ public class FunctionExtractingFunctionCatalog
 			throw new IllegalStateException("No such app");
 		}
 		this.deployer.undeploy(id);
-		this.deployed.remove(id);
-		this.names.remove(name);
 		String path = this.deployed.remove(id);
-		return new DeployedArtifact(id, name, path);
+		this.names.remove(name);
+		this.ids.remove(id);
+		return new DeployedArtifact(name, id, path);
 	}
 
 	private Object inspect(Object arg, String method) {
@@ -170,11 +185,25 @@ public class FunctionExtractingFunctionCatalog
 	}
 
 	private Object invoke(Class<?> type, String method, Object... arg) {
+		Set<Object> results = new LinkedHashSet<>();
 		for (String id : this.deployed.keySet()) {
 			Object catalog = this.deployer.getBean(id, type);
 			if (catalog == null) {
 				continue;
 			}
+			String name = this.ids.get(id);
+			String prefix = name + "/";
+			if (arg.length == 1) {
+				if (arg[0] instanceof String) {
+					String specific = arg[0].toString();
+					if (specific.startsWith(prefix)) {
+						arg[0] = specific.substring(prefix.length());
+					}
+					else {
+						continue;
+					}
+				}
+			}
 			try {
 				MethodInvoker invoker = new MethodInvoker();
 				invoker.setTargetObject(catalog);
@@ -183,14 +212,25 @@ public class FunctionExtractingFunctionCatalog
 				invoker.prepare();
 				Object result = invoker.invoke();
 				if (result != null) {
-					return result;
+					if (result instanceof Collection) {
+						for (Object value : (Collection<?>) result) {
+							results.add(prefix + value);
+						}
+					}
+					else if (result instanceof String) {
+						return prefix + result;
+					}
+
+					else {
+						return result;
+					}
 				}
 			}
 			catch (Exception e) {
 				throw new IllegalStateException("Cannot extract catalog", e);
 			}
 		}
-		return null;
+		return arg.length > 0 ? null : results;
 	}
 
 	public Map<String, Object> deployed() {

spring-cloud-function-deployer/src/test/java/org/springframework/cloud/function/deployer/FunctionExtractingFunctionCatalogIntegrationTests.java

@@ -15,13 +15,17 @@
  */
 package org.springframework.cloud.function.deployer;
 
+import java.net.URI;
+
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
-import org.junit.Ignore;
 import org.junit.Test;
 
 import org.springframework.boot.test.web.client.TestRestTemplate;
 import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.RequestEntity;
+import org.springframework.http.ResponseEntity;
 import org.springframework.util.SocketUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -30,19 +34,33 @@ import static org.assertj.core.api.Assertions.assertThat;
  * @author Dave Syer
  *
  */
-@Ignore
-// TODO: Salvage some stuff from this project
 public class FunctionExtractingFunctionCatalogIntegrationTests {
 
 	private static ConfigurableApplicationContext context;
 	private static int port;
 
 	@BeforeClass
-	public static void open() {
+	public static void open() throws Exception {
 		port = SocketUtils.findAvailableTcpPort();
 		// System.setProperty("debug", "true");
 		context = new ApplicationRunner().start("--server.port=" + port,
 				"--spring.cloud.stream.enabled=false");
+		deploy("sample", "maven://com.example:function-sample:1.0.0.BUILD-SNAPSHOT");
+	}
+
+	private static void deploy(String name, String path) throws Exception {
+		ResponseEntity<String> result = new TestRestTemplate().postForEntity(
+				"http://localhost:" + port + "/admin/" + name + "?path=" + path, "",
+				String.class);
+		assertThat(result.getStatusCode()).isEqualTo(HttpStatus.OK);
+	}
+
+	private static String undeploy(String name) throws Exception {
+		ResponseEntity<String> result = new TestRestTemplate().exchange(RequestEntity
+				.delete(new URI("http://localhost:" + port + "/admin/" + name)).build(),
+				String.class);
+		assertThat(result.getStatusCode()).isEqualTo(HttpStatus.OK);
+		return result.getBody();
 	}
 
 	@AfterClass
@@ -52,18 +70,49 @@ public class FunctionExtractingFunctionCatalogIntegrationTests {
 		}
 	}
 
+	@Test
+	public void listing() {
+		assertThat(new TestRestTemplate()
+				.getForObject("http://localhost:" + port + "/admin", String.class))
+						.startsWith("{").contains("sample");
+	}
+
 	@Test
 	public void words() {
 		assertThat(new TestRestTemplate()
-				.getForObject("http://localhost:" + port + "/words", String.class))
-						.isEqualTo("{\"value\":\"foo\"}{\"value\":\"bar\"}");
+				.getForObject("http://localhost:" + port + "/sample/words", String.class))
+						.isEqualTo("[{\"value\":\"foo\"},{\"value\":\"bar\"}]");
 	}
 
 	@Test
 	public void uppercase() {
 		assertThat(new TestRestTemplate().postForObject(
-				"http://localhost:" + port + "/uppercase", "{\"value\":\"foo\"}",
-				String.class)).isEqualTo("{\"value\":\"FOO\"}");
+				"http://localhost:" + port + "/sample/uppercase", "{\"value\":\"foo\"}",
+				String.class)).isEqualTo("[{\"value\":\"FOO\"}]");
+	}
+
+	@Test
+	public void another() throws Exception {
+		deploy("strings", "maven://com.example:function-sample:1.0.0.BUILD-SNAPSHOT");
+		assertThat(new TestRestTemplate().getForObject(
+				"http://localhost:" + port + "/strings/words", String.class))
+						.isEqualTo("[\"foo\",\"bar\"]");
+	}
+
+	@Test
+	public void cycle() throws Exception {
+		String undeploy = undeploy("sample");
+		assertThat(undeploy.contains("\"name\":\"sample\""));
+		assertThat(undeploy.contains(
+				"\"path\":\"maven://com.example:function-sample-pojo:1.0.0.BUILD-SNAPSHOT\""));
+		ResponseEntity<String> result = new TestRestTemplate().exchange(RequestEntity
+				.get(new URI("http://localhost:" + port + "/sample/words")).build(),
+				String.class);
+		assertThat(result.getStatusCode()).isEqualTo(HttpStatus.NOT_FOUND);
+		deploy("sample", "maven://com.example:function-sample-pojo:1.0.0.BUILD-SNAPSHOT");
+		assertThat(new TestRestTemplate().postForObject(
+				"http://localhost:" + port + "/sample/uppercase", "{\"value\":\"foo\"}",
+				String.class)).isEqualTo("[{\"value\":\"FOO\"}]");
 	}
 
 }

spring-cloud-function-deployer/src/test/java/org/springframework/cloud/function/deployer/FunctionExtractingFunctionCatalogTests.java

@@ -15,21 +15,13 @@
  */
 package org.springframework.cloud.function.deployer;
 
-import java.util.Arrays;
-import java.util.Collections;
-
 import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
-import org.springframework.boot.loader.thin.ArchiveUtils;
 import org.springframework.boot.loader.tools.LogbackInitializer;
-import org.springframework.cloud.deployer.spi.core.AppDefinition;
-import org.springframework.cloud.deployer.spi.core.AppDeploymentRequest;
-import org.springframework.core.io.FileSystemResource;
-import org.springframework.core.io.Resource;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -55,8 +47,10 @@ public class FunctionExtractingFunctionCatalogTests {
 	@Before
 	public void init() throws Exception {
 		if (id == null) {
-			id = deploy("maven://com.example:function-sample:1.0.0.BUILD-SNAPSHOT");
+			deploy("sample", "maven://com.example:function-sample:1.0.0.BUILD-SNAPSHOT");
 			// "--debug");
+			id = deploy("pojos",
+					"maven://com.example:function-sample-pojo:1.0.0.BUILD-SNAPSHOT");
 		}
 	}
 
@@ -64,38 +58,63 @@ public class FunctionExtractingFunctionCatalogTests {
 	public static void close() {
 		if (id != null) {
 			deployer.undeploy("sample");
+			deployer.undeploy("pojos");
 		}
 	}
 
+	@Test
+	public void listFunctions() throws Exception {
+		assertThat(deployer.getFunctionNames()).contains("sample/uppercase",
+				"pojos/uppercase");
+	}
+
+	@Test
+	public void nameFunction() throws Exception {
+		assertThat(deployer.getName(deployer.lookupFunction("sample/uppercase")))
+				.isEqualTo("sample/uppercase");
+	}
+
 	@Test
 	public void deployAndExtractFunctions() throws Exception {
 		// This one can only work if you change the boot classpath to contain reactor-core
 		// and reactive-streams
 		expected.expect(ClassCastException.class);
 		@SuppressWarnings("unchecked")
-		Flux<String> result = (Flux<String>) deployer.lookupFunction("uppercase")
+		Flux<String> result = (Flux<String>) deployer.lookupFunction("pojos/uppercase")
 				.apply(Flux.just("foo"));
 		assertThat(result.blockFirst()).isEqualTo("FOO");
 	}
 
+	@Test
+	public void listConsumers() throws Exception {
+		assertThat(deployer.getConsumerNames()).isEmpty();
+	}
+
 	@Test
 	public void deployAndExtractConsumers() throws Exception {
-		assertThat(deployer.lookupConsumer("sink")).isNull();
+		assertThat(deployer.lookupConsumer("pojos/sink")).isNull();
+	}
+
+	@Test
+	public void listSuppliers() throws Exception {
+		assertThat(deployer.getSupplierNames()).contains("sample/words", "pojos/words");
+	}
+
+	@Test
+	public void nameSupplier() throws Exception {
+		assertThat(deployer.getName(deployer.lookupSupplier("sample/words")))
+				.isEqualTo("sample/words");
 	}
 
 	@Test
 	public void deployAndExtractSuppliers() throws Exception {
-		assertThat(deployer.lookupSupplier("words")).isNotNull();
+		assertThat(deployer.lookupSupplier("sample/words")).isNotNull();
+		assertThat(deployer.lookupSupplier("pojos/words")).isNotNull();
 	}
 
-	private static String deploy(String jarName, String... args) throws Exception {
-		Resource resource = new FileSystemResource(
-				ArchiveUtils.getArchiveRoot(ArchiveUtils.getArchive(jarName)));
-		AppDefinition definition = new AppDefinition(resource.getFilename(),
-				Collections.emptyMap());
-		AppDeploymentRequest request = new AppDeploymentRequest(definition, resource,
-				Collections.emptyMap(), Arrays.asList(args));
-		String deployed = deployer.deploy("sample", request);
+	private static String deploy(String name, String path, String... args)
+			throws Exception {
+		String deployed = deployer.deploy(name, path, args);
 		return deployed;
 	}