Expose service meta-data

InitializrMetadataBuilder can now merge a number of resources into a
single meta-data instance. A new `/metadata/service` endpoint is now
available and exposes the service meta-data of the current instance.

Combining those two, it is now possible to bootstrap an instance without
a single line of configuration; instead, the meta-data are built from the
content of a json document describing the service meta-data. This
document can be fetched remotely (via the new endpoint) or loaded from
a local file.

Each capability, including the InitializrConfiguration has now a `merge`
method with a "last wins" strategy. For collections, only unknown
elements are added.

Closes gh-88

initializr/src/main/groovy/io/spring/initializr/InitializrConfiguration.groovy

@@ -26,6 +26,10 @@ class InitializrConfiguration {
 
 	final Env env = new Env()
 
+	void merge(InitializrConfiguration other) {
+		env.merge(other.env)
+	}
+
 	/**
 	 * Generate a suitable application mame based on the specified name. If no suitable
 	 * application name can be generated from the specified {@code name}, the
@@ -116,5 +120,13 @@ class InitializrConfiguration {
 			this.artifactRepository = artifactRepository
 		}
 
+		void merge(Env other) {
+			artifactRepository = other.artifactRepository
+			springBootMetadataUrl = other.springBootMetadataUrl
+			fallbackApplicationName = other.fallbackApplicationName
+			invalidApplicationNames = other.invalidApplicationNames
+			forceSsl = other.forceSsl
+		}
+
 	}
 }

initializr/src/main/groovy/io/spring/initializr/config/InitializrAutoConfiguration.groovy

@@ -82,7 +82,7 @@ class InitializrAutoConfiguration {
 	@Bean
 	@ConditionalOnMissingBean
 	InitializrMetadata initializrMetadata(InitializrProperties properties) {
-		new InitializrMetadataBuilder().fromConfiguration(properties).build()
+		InitializrMetadataBuilder.fromInitializrProperties(properties).build()
 	}
 
 	@Bean

initializr/src/main/groovy/io/spring/initializr/generator/ProjectRequest.groovy

@@ -66,7 +66,7 @@ class ProjectRequest {
 	 * Initializes this instance with the defaults defined in the specified {@link InitializrMetadata}.
 	 */
 	void initialize(InitializrMetadata metadata) {
-		metadata.defaults().forEach { key, value ->
+		metadata.defaults().each { key, value ->
 			if (owner.hasProperty(key)) {
 				owner.setProperty(key, value)
 			}

initializr/src/main/groovy/io/spring/initializr/metadata/DependenciesCapability.groovy

@@ -49,6 +49,20 @@ class DependenciesCapability extends ServiceCapability<List<DependencyGroup>> {
 	}
 
 	void validate() {
+		index()
+	}
+
+	@Override
+	void merge(List<DependencyGroup> otherContent) {
+		otherContent.each { group ->
+			if (!content.find { group.name.equals(it.name)}) {
+				content << group
+			}
+		}
+		index()
+	}
+
+	private void index() {
 		indexedDependencies.clear()
 		content.each { group ->
 			group.content.each { dependency ->

initializr/src/main/groovy/io/spring/initializr/metadata/InitializrMetadata.groovy

@@ -41,22 +41,46 @@ class InitializrMetadata {
 
 	final SingleSelectCapability languages = new SingleSelectCapability('language')
 
-	final TextCapability name = new TextCapability('name', 'demo')
+	final TextCapability name = new TextCapability('name')
 
-	final TextCapability description = new TextCapability('description', 'Demo project for Spring Boot')
+	final TextCapability description = new TextCapability('description')
 
-	final TextCapability groupId = new TextCapability('groupId', 'org.test')
+	final TextCapability groupId = new TextCapability('groupId')
 
 	final TextCapability artifactId = new ArtifactIdCapability(name)
 
-	final TextCapability version = new TextCapability('version', '0.0.1-SNAPSHOT')
+	final TextCapability version = new TextCapability('version')
 
 	final TextCapability packageName = new PackageCapability(name)
 
-	InitializrMetadata(InitializrConfiguration configuration) {
+	InitializrMetadata() {
+		this(new InitializrConfiguration())
+	}
+
+	protected InitializrMetadata(InitializrConfiguration configuration) {
 		this.configuration = configuration
 	}
 
+	/**
+	 * Merge this instance with the specified argument
+	 * @param other
+	 */
+	void merge(InitializrMetadata other) {
+		this.configuration.merge(other.configuration)
+		this.dependencies.merge(other.dependencies)
+		this.types.merge(other.types)
+		this.bootVersions.merge(other.bootVersions)
+		this.packagings.merge(other.packagings)
+		this.javaVersions.merge(other.javaVersions)
+		this.languages.merge(other.languages)
+		this.name.merge(other.name)
+		this.description.merge(other.description)
+		this.groupId.merge(other.groupId)
+		this.artifactId.merge(other.artifactId)
+		this.version.merge(other.version)
+		this.packageName.merge(other.packageName)
+	}
+
 	/**
 	 * Validate the meta-data.
 	 */

initializr/src/main/groovy/io/spring/initializr/metadata/InitializrMetadataBuilder.groovy

@@ -16,10 +16,18 @@
 
 package io.spring.initializr.metadata
 
+import java.nio.charset.Charset
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import groovy.util.logging.Log
 import io.spring.initializr.InitializrConfiguration
 
+import org.springframework.core.io.Resource
+import org.springframework.util.StreamUtils
+
 /**
- * Builder for {@link InitializrMetadata}.
+ * Builder for {@link InitializrMetadata}. Allows to read meta-data from any arbitrary resource,
+ * including remote URLs.
  *
  * @author Stephane Nicoll
  * @since 1.0
@@ -28,19 +36,60 @@ import io.spring.initializr.InitializrConfiguration
 class InitializrMetadataBuilder {
 
 	private final List<InitializrMetadataCustomizer> customizers = []
-	private InitializrConfiguration configuration
+	private final InitializrConfiguration configuration
 
-	/**
-	 * Adds the specified configuration.
-	 * @see InitializrProperties
-	 */
-	InitializrMetadataBuilder fromConfiguration(InitializrProperties configuration) {
+	private InitializrMetadataBuilder(InitializrConfiguration configuration) {
 		this.configuration = configuration
-		withCustomizer(new InitializerPropertiesCustomizer(configuration))
 	}
 
 	/**
-	 * Adds a {@link InitializrMetadataCustomizer}. customizers are invoked in their
+	 * Create a builder instance from the specified {@link InitializrProperties}. Initialize
+	 * the configuration to use.
+	 * @see #withInitializrProperties(InitializrProperties)
+	 */
+	public static InitializrMetadataBuilder fromInitializrProperties(InitializrProperties configuration) {
+		new InitializrMetadataBuilder(configuration).withInitializrProperties(configuration)
+	}
+
+	/**
+	 * Create an empty builder instance with a default {@link InitializrConfiguration}
+	 */
+	public static InitializrMetadataBuilder create() {
+		new InitializrMetadataBuilder(new InitializrConfiguration())
+	}
+
+
+	/**
+	 * Add a {@link InitializrProperties} to be merged with other content. Merges the settings only
+	 * and not the configuration.
+	 * @see #withInitializrProperties(InitializrProperties, boolean)
+	 */
+	InitializrMetadataBuilder withInitializrProperties(InitializrProperties properties) {
+		withInitializrProperties(properties, false)
+	}
+
+	/**
+	 * Add a {@link InitializrProperties} to be merged with other content.
+	 * @param properties the settings to merge onto this instance
+	 * @param mergeConfiguration specify if service configuration should be merged as well
+	 */
+	InitializrMetadataBuilder withInitializrProperties(InitializrProperties properties, boolean mergeConfiguration) {
+		if (mergeConfiguration) {
+			this.configuration.merge(properties)
+		}
+		withCustomizer(new InitializerPropertiesCustomizer(properties))
+	}
+
+	/**
+	 * Add a {@link InitializrMetadata} to be merged with other content.
+	 * @param resource a resource to a json document describing the meta-data to include
+	 */
+	InitializrMetadataBuilder withInitializrMetadata(Resource resource) {
+		withCustomizer(new ResourceInitializrMetadataCustomizer(resource))
+	}
+
+	/**
+	 * Add a {@link InitializrMetadataCustomizer}. customizers are invoked in their
 	 * order of addition.
 	 * @see InitializrMetadataCustomizer
 	 */
@@ -54,12 +103,13 @@ class InitializrMetadataBuilder {
 	 */
 	InitializrMetadata build() {
 		InitializrConfiguration config = this.configuration ?: new InitializrConfiguration()
-		InitializrMetadata instance = createInstance(config)
+		InitializrMetadata metadata = createInstance(config)
 		for (InitializrMetadataCustomizer customizer : customizers) {
-			customizer.customize(instance)
+			customizer.customize(metadata)
 		}
-		instance.validate()
-		instance
+		applyDefaults(metadata)
+		metadata.validate()
+		metadata
 	}
 
 	/**
@@ -69,7 +119,25 @@ class InitializrMetadataBuilder {
 		new InitializrMetadata(configuration)
 	}
 
-	static class InitializerPropertiesCustomizer implements InitializrMetadataCustomizer {
+	/**
+	 * Apply defaults to capabilities that have no value.
+	 */
+	protected applyDefaults(InitializrMetadata metadata) {
+		if (!metadata.name.content) {
+			metadata.name.content = 'demo'
+		}
+		if (!metadata.description.content) {
+			metadata.description.content = 'Demo project for Spring Boot'
+		}
+		if (!metadata.groupId.content) {
+			metadata.groupId.content = 'org.test'
+		}
+		if (!metadata.version.content) {
+			metadata.version.content = '0.0.1-SNAPSHOT'
+		}
+	}
+
+	private static class InitializerPropertiesCustomizer implements InitializrMetadataCustomizer {
 
 		private final InitializrProperties properties
 
@@ -78,21 +146,42 @@ class InitializrMetadataBuilder {
 		}
 
 		@Override
-		void customize(InitializrMetadata metadata) { // NICE: merge
-			metadata.dependencies.content.addAll(properties.dependencies)
-			metadata.types.content.addAll(properties.types)
-			metadata.bootVersions.content.addAll(properties.bootVersions)
-			metadata.packagings.content.addAll(properties.packagings)
-			metadata.javaVersions.content.addAll(properties.javaVersions)
-			metadata.languages.content.addAll(properties.languages)
-			metadata.groupId.content = properties.defaults.groupId
-			metadata.artifactId.content = properties.defaults.artifactId
-			metadata.version.content = properties.defaults.version
-			metadata.name.content = properties.defaults.name
-			metadata.description.content = properties.defaults.description
-			metadata.packageName.content = properties.defaults.packageName
+		void customize(InitializrMetadata metadata) {
+			metadata.dependencies.merge(properties.dependencies)
+			metadata.types.merge(properties.types)
+			metadata.bootVersions.merge(properties.bootVersions)
+			metadata.packagings.merge(properties.packagings)
+			metadata.javaVersions.merge(properties.javaVersions)
+			metadata.languages.merge(properties.languages)
+			metadata.groupId.merge(properties.defaults.groupId)
+			metadata.artifactId.merge(properties.defaults.artifactId)
+			metadata.version.merge(properties.defaults.version)
+			metadata.name.merge(properties.defaults.name)
+			metadata.description.merge(properties.defaults.description)
+			metadata.packageName.merge(properties.defaults.packageName)
 		}
 	}
 
+	@Log
+	private static class ResourceInitializrMetadataCustomizer implements InitializrMetadataCustomizer {
+
+		private static final Charset UTF_8 = Charset.forName('UTF-8')
+
+		private final Resource resource
+
+		ResourceInitializrMetadataCustomizer(Resource resource) {
+			this.resource = resource
+		}
+
+		@Override
+		void customize(InitializrMetadata metadata) {
+			log.info("Loading initializr meta-data from $resource")
+			def content = StreamUtils.copyToString(resource.getInputStream(), UTF_8)
+			ObjectMapper objectMapper = new ObjectMapper()
+			def anotherMetadata = objectMapper.readValue(content, InitializrMetadata)
+			metadata.merge(anotherMetadata)
+		}
+
+	}
 
 }

initializr/src/main/groovy/io/spring/initializr/metadata/InitializrProperties.groovy

@@ -16,6 +16,7 @@
 
 package io.spring.initializr.metadata
 
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties
 import io.spring.initializr.InitializrConfiguration
 
 import org.springframework.boot.context.properties.ConfigurationProperties
@@ -27,6 +28,7 @@ import org.springframework.boot.context.properties.ConfigurationProperties
  * @since 1.0
  */
 @ConfigurationProperties(prefix = 'initializr', ignoreUnknownFields = false)
+@JsonIgnoreProperties(["dependencies", "types", "packagings", "javaVersions", "languages", "bootVersions", "defaults"])
 class InitializrProperties extends InitializrConfiguration {
 
 	final List<DependencyGroup> dependencies = []

initializr/src/main/groovy/io/spring/initializr/metadata/ServiceCapability.groovy

@@ -16,6 +16,10 @@
 
 package io.spring.initializr.metadata
 
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+
+import org.springframework.util.Assert
+
 /**
  * Defines a capability of the initializr service. Each capability
  * is defined by a id and a {@link ServiceCapabilityType type}.
@@ -23,6 +27,7 @@ package io.spring.initializr.metadata
  * @author Stephane Nicoll
  * @since 1.0
  */
+@JsonIgnoreProperties(["default", "all"])
 abstract class ServiceCapability<T> {
 
 	final String id
@@ -42,5 +47,26 @@ abstract class ServiceCapability<T> {
 	 */
 	abstract T getContent()
 
+	/**
+	 * Merge the content of this instance with the specified content.
+	 * @see #merge(io.spring.initializr.metadata.ServiceCapability)
+	 */
+	abstract void merge(T otherContent)
+
+	/**
+	 * Merge this capability with the specified argument. The service capabilities
+	 * should match (i.e have the same {@code id} and {@code type}). Sub-classes
+	 * may merge additional content.
+	 */
+	void merge(ServiceCapability<T> other) {
+		Assert.notNull(other, "Other must not be null")
+		Assert.state(this.id.equals(other.id))
+		Assert.state(this.type.equals(other.type))
+		if (other.description) {
+			this.description = other.description
+		}
+		merge(other.content)
+	}
+
 }
 

initializr/src/main/groovy/io/spring/initializr/metadata/SingleSelectCapability.groovy

@@ -16,6 +16,9 @@
 
 package io.spring.initializr.metadata
 
+import com.fasterxml.jackson.annotation.JsonCreator
+import com.fasterxml.jackson.annotation.JsonProperty
+
 /**
  * A {@link ServiceCapabilityType#SINGLE_SELECT single select} capability.
  *
@@ -26,7 +29,8 @@ class SingleSelectCapability extends ServiceCapability<List<DefaultMetadataEleme
 
 	final List<DefaultMetadataElement> content = []
 
-	SingleSelectCapability(String id) {
+	@JsonCreator
+	SingleSelectCapability(@JsonProperty("id") String id) {
 		super(id, ServiceCapabilityType.SINGLE_SELECT)
 	}
 
@@ -37,4 +41,21 @@ class SingleSelectCapability extends ServiceCapability<List<DefaultMetadataEleme
 	   return content.find { it.default }
 	}
 
+	/**
+	 * Return the element with the specified id or {@code null} if no such
+	 * element exists.
+	 */
+	DefaultMetadataElement get(String id) {
+		return content.find { id.equals(it.id)}
+	}
+
+	@Override
+	void merge(List<DefaultMetadataElement> otherContent) {
+		otherContent.each {
+			if (!get(it.id)) {
+				content << it
+			}
+		}
+	}
+
 }

initializr/src/main/groovy/io/spring/initializr/metadata/TextCapability.groovy

@@ -16,6 +16,9 @@
 
 package io.spring.initializr.metadata
 
+import com.fasterxml.jackson.annotation.JsonCreator
+import com.fasterxml.jackson.annotation.JsonProperty
+
 /**
  * A {@link ServiceCapabilityType#TEXT text} capability.
  *
@@ -26,7 +29,8 @@ class TextCapability extends ServiceCapability<String> {
 
 	String content
 
-	TextCapability(String id) {
+	@JsonCreator
+	TextCapability(@JsonProperty("id") String id) {
 		super(id, ServiceCapabilityType.TEXT);
 	}
 
@@ -35,5 +39,12 @@ class TextCapability extends ServiceCapability<String> {
 		this.content = content
 	}
 
+	@Override
+	void merge(String otherContent) {
+		if (otherContent) {
+			this.content = otherContent
+		}
+	}
+
 }
 

initializr/src/main/groovy/io/spring/initializr/metadata/TypeCapability.groovy

@@ -45,4 +45,13 @@ class TypeCapability extends ServiceCapability<List<Type>> {
 		return content.find { it.default }
 	}
 
+	@Override
+	void merge(List<Type> otherContent) {
+		otherContent.each {
+			if (!get(it.id)) {
+				content << it
+			}
+		}
+	}
+
 }

initializr/src/main/groovy/io/spring/initializr/web/MainController.groovy

@@ -24,6 +24,7 @@ import io.spring.initializr.mapper.InitializrMetadataV2JsonMapper
 import io.spring.initializr.mapper.InitializrMetadataVersion
 import io.spring.initializr.generator.ProjectGenerator
 import io.spring.initializr.generator.ProjectRequest
+import io.spring.initializr.metadata.InitializrMetadata
 
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.http.HttpHeaders
@@ -62,6 +63,12 @@ class MainController extends AbstractInitializrController {
 		request
 	}
 
+	@RequestMapping(value = "/metadata/service", produces = ["application/json"])
+	@ResponseBody
+	InitializrMetadata config() {
+		metadataProvider.get()
+	}
+
 	@RequestMapping(value = "/", produces = ["text/plain"])
 	ResponseEntity<String> serviceCapabilities(
 			@RequestHeader(value = HttpHeaders.USER_AGENT, required = false) String userAgent) {

initializr/src/test/groovy/io/spring/initializr/generator/ProjectRequestTests.groovy

@@ -16,9 +16,8 @@
 
 package io.spring.initializr.generator
 
-import io.spring.initializr.InitializrConfiguration
 import io.spring.initializr.metadata.Dependency
-import io.spring.initializr.metadata.InitializrMetadata
+import io.spring.initializr.metadata.InitializrMetadataBuilder
 import io.spring.initializr.test.InitializrMetadataTestBuilder
 import org.junit.Rule
 import org.junit.Test
@@ -37,7 +36,7 @@ class ProjectRequestTests {
 
 	@Test
 	void initializeProjectRequest() {
-		def metadata = new InitializrMetadata(new InitializrConfiguration())
+		def metadata = InitializrMetadataBuilder.create().build()
 		metadata.groupId.content = 'org.acme'
 		metadata.artifactId.content = 'my-project'
 		ProjectRequest request = new ProjectRequest()

initializr/src/test/groovy/io/spring/initializr/metadata/DependenciesCapabilityTest.groovy

@@ -20,6 +20,8 @@ import org.junit.Rule
 import org.junit.Test
 import org.junit.rules.ExpectedException
 
+import static org.junit.Assert.assertEquals
+import static org.junit.Assert.assertNotNull
 import static org.junit.Assert.assertNull
 import static org.junit.Assert.assertSame
 
@@ -83,6 +85,22 @@ class DependenciesCapabilityTest {
 		capability.validate()
 	}
 
+	@Test
+	void mergeAddEntry() {
+		DependenciesCapability capability = createDependenciesCapability('foo',
+				new Dependency(id: 'first'), new Dependency(id: 'second'))
+
+		DependenciesCapability anotherCapability = createDependenciesCapability('foo',
+				new Dependency(id: 'bar'), new Dependency(id: 'biz'))
+		anotherCapability.content << createDependencyGroup('bar', new Dependency(id: 'third'))
+
+		capability.merge(anotherCapability)
+		assertEquals 2, capability.content.size()
+		assertNotNull capability.get('first')
+		assertNotNull capability.get('second')
+		assertNotNull capability.get('third')
+	}
+
 	private static DependenciesCapability createDependenciesCapability(String groupName, Dependency... dependencies) {
 		DependenciesCapability capability = new DependenciesCapability()
 		DependencyGroup group = createDependencyGroup(groupName, dependencies)

initializr/src/test/groovy/io/spring/initializr/metadata/InitializrMetadataBuilderTests.groovy

@@ -16,6 +16,7 @@
 
 package io.spring.initializr.metadata
 
+import io.spring.initializr.InitializrConfiguration
 import org.junit.Test
 
 import org.springframework.beans.factory.config.YamlPropertiesFactoryBean
@@ -34,11 +35,92 @@ class InitializrMetadataBuilderTests {
 	@Test
 	void loadDefaultConfig() {
 		def bean = load(new ClassPathResource("application-test-default.yml"))
-		def metadata = new InitializrMetadataBuilder().fromConfiguration(bean).build()
+		def metadata = InitializrMetadataBuilder.fromInitializrProperties(bean).build()
+		assertDefaultConfig(metadata)
+	}
+
+	@Test
+	void mergeIdenticalConfig() {
+		def bean = load(new ClassPathResource("application-test-default.yml"))
+		def metadata = InitializrMetadataBuilder
+				.fromInitializrProperties(bean)
+				.withInitializrProperties(bean, true).build()
+		assertDefaultConfig(metadata)
+	}
+
+	@Test
+	void mergeConfig() {
+		def config = load(new ClassPathResource("application-test-default.yml"))
+		def customDefaultsConfig = load(new ClassPathResource("application-test-custom-defaults.yml"))
+		def metadata = InitializrMetadataBuilder
+				.fromInitializrProperties(config)
+				.withInitializrProperties(customDefaultsConfig).build()
+		assertDefaultConfig(metadata)
+		assertEquals 'org.foo', metadata.groupId.content
+		assertEquals 'foo-bar', metadata.artifactId.content
+		assertEquals '1.2.4-SNAPSHOT', metadata.version.content
+		assertEquals 'FooBar', metadata.name.content
+		assertEquals 'FooBar Project', metadata.description.content
+		assertEquals 'org.foo.demo', metadata.packageName.content
+	}
+
+	@Test
+	void mergeMetadata() {
+		def metadata = InitializrMetadataBuilder.create().withInitializrMetadata(
+				new ClassPathResource('metadata/service/test-min.json')).build()
+		assertEquals false, metadata.configuration.env.forceSsl
+		assertEquals 1, metadata.dependencies.content.size()
+		Dependency dependency = metadata.dependencies.get('test')
+		assertNotNull dependency
+		assertEquals 'org.springframework.boot', dependency.groupId
+		assertEquals 1, metadata.types.content.size()
+		assertEquals 2, metadata.bootVersions.content.size()
+		assertEquals 2, metadata.packagings.content.size()
+		assertEquals 1, metadata.javaVersions.content.size()
+		assertEquals 2, metadata.languages.content.size()
+		assertEquals 'meta-data-merge', metadata.name.content
+		assertEquals 'Demo project for meta-data merge', metadata.description.content
+		assertEquals 'org.acme', metadata.groupId.content
+		assertEquals 'meta-data', metadata.artifactId.content
+		assertEquals '1.0.0-SNAPSHOT', metadata.version.content
+		assertEquals 'org.acme.demo', metadata.packageName.content
+	}
+
+	@Test
+	void mergeConfigurationDisabledByDefault() {
+		def config = load(new ClassPathResource("application-test-default.yml"))
+		def customDefaultsConfig = load(new ClassPathResource("application-test-custom-env.yml"))
+		def metadata = InitializrMetadataBuilder
+				.fromInitializrProperties(config)
+				.withInitializrProperties(customDefaultsConfig).build()
+		InitializrConfiguration.Env defaultEnv = new InitializrConfiguration().env
+		InitializrConfiguration.Env actualEnv = metadata.configuration.env
+		assertEquals defaultEnv.artifactRepository, actualEnv.artifactRepository
+		assertEquals defaultEnv.springBootMetadataUrl, actualEnv.springBootMetadataUrl
+		assertEquals defaultEnv.fallbackApplicationName, actualEnv.fallbackApplicationName
+		assertEquals defaultEnv.forceSsl, actualEnv.forceSsl
+	}
+
+	@Test
+	void mergeConfiguration() {
+		def config = load(new ClassPathResource("application-test-default.yml"))
+		def customDefaultsConfig = load(new ClassPathResource("application-test-custom-env.yml"))
+		def metadata = InitializrMetadataBuilder
+				.fromInitializrProperties(config)
+				.withInitializrProperties(customDefaultsConfig, true).build()
+		InitializrConfiguration.Env defaultEnv = new InitializrConfiguration().env
+		InitializrConfiguration.Env actualEnv = metadata.configuration.env
+		assertEquals 'https://repo.spring.io/lib-release/', actualEnv.artifactRepository
+		assertEquals defaultEnv.springBootMetadataUrl, actualEnv.springBootMetadataUrl
+		assertEquals 'FooBarApplication', actualEnv.fallbackApplicationName
+		assertEquals false, actualEnv.forceSsl
+	}
+
+	private static assertDefaultConfig(InitializrMetadata metadata) {
 		assertNotNull metadata
-		assertEquals("Wrong number of dependencies", 9, metadata.dependencies.all.size())
-		assertEquals("Wrong number of dependency group", 2, metadata.dependencies.content.size())
-		assertEquals("Wrong number of types", 4, metadata.types.content.size())
+		assertEquals "Wrong number of dependencies", 9, metadata.dependencies.all.size()
+		assertEquals "Wrong number of dependency group", 2, metadata.dependencies.content.size()
+		assertEquals "Wrong number of types", 4, metadata.types.content.size()
 	}
 
 	@Test
@@ -46,7 +128,7 @@ class InitializrMetadataBuilderTests {
 		def group = new DependencyGroup(name: 'Extra')
 		def dependency = new Dependency(id: 'com.foo:foo:1.0.0')
 		group.content << dependency
-		def metadata = new InitializrMetadataBuilder().withCustomizer(new InitializrMetadataCustomizer() {
+		def metadata = InitializrMetadataBuilder.create().withCustomizer(new InitializrMetadataCustomizer() {
 			@Override
 			void customize(InitializrMetadata metadata) {
 				metadata.dependencies.content << group

initializr/src/test/groovy/io/spring/initializr/metadata/SingleSelectCapabilityTests.groovy

@@ -49,4 +49,20 @@ class SingleSelectCapabilityTests {
 		assertEquals second, capability.default
 	}
 
+	@Test
+	void mergeAddEntry() {
+		SingleSelectCapability capability = new SingleSelectCapability('test')
+		def foo = new DefaultMetadataElement(id: 'foo', default: false)
+		capability.content << foo
+
+		SingleSelectCapability anotherCapability = new SingleSelectCapability('test')
+		def bar = new DefaultMetadataElement(id: 'bar', default: false)
+		anotherCapability.content << bar
+
+		capability.merge(anotherCapability)
+		assertEquals 2, capability.content.size()
+		assertEquals foo, capability.get('foo')
+		assertEquals bar, capability.get('bar')
+	}
+
 }

initializr/src/test/groovy/io/spring/initializr/metadata/TextCapabilityTests.groovy

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2012-2015 the original author or authors.
+ *
+ * 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 io.spring.initializr.metadata
+
+import org.junit.Test
+
+import static org.junit.Assert.assertEquals
+
+/**
+ * @author Stephane Nicoll
+ */
+class TextCapabilityTests {
+
+	@Test
+	void mergeContent() {
+		TextCapability capability = new TextCapability('foo', '1234')
+		capability.merge(new TextCapability('foo', '4567'))
+		assertEquals 'foo', capability.id
+		assertEquals ServiceCapabilityType.TEXT, capability.type
+		assertEquals '4567', capability.content
+	}
+
+	@Test
+	void mergeDescription() {
+		TextCapability capability = new TextCapability('foo', '1234')
+		def other = new TextCapability('foo', '')
+		other.description = 'my description'
+		capability.merge(other)
+		assertEquals 'foo', capability.id
+		assertEquals ServiceCapabilityType.TEXT, capability.type
+		assertEquals '1234', capability.content
+		assertEquals 'my description', capability.description
+	}
+
+}

initializr/src/test/groovy/io/spring/initializr/metadata/TypeCapabilityTests.groovy

@@ -48,4 +48,22 @@ class TypeCapabilityTests {
 		assertEquals second, capability.default
 	}
 
+	@Test
+	void mergeAddEntry() {
+		TypeCapability capability = new TypeCapability()
+		def foo = new Type(id: 'foo', default: false)
+		capability.content << foo
+
+		TypeCapability anotherCapability = new TypeCapability()
+		def foo2 =new Type(id: 'foo', default: true)
+		def bar =new Type(id: 'bar', default: true)
+		anotherCapability.content << foo2 << bar
+
+		capability.merge(anotherCapability)
+		assertEquals 2, capability.content.size()
+		assertEquals foo, capability.get('foo')
+		assertEquals bar, capability.get('bar')
+		assertEquals bar, capability.default
+	}
+
 }

initializr/src/test/groovy/io/spring/initializr/support/SpringBootMetadataReaderTests.groovy

@@ -16,8 +16,8 @@
 
 package io.spring.initializr.support
 
-import io.spring.initializr.InitializrConfiguration
 import io.spring.initializr.metadata.InitializrMetadata
+import io.spring.initializr.metadata.InitializrMetadataBuilder
 import org.junit.Test
 
 import static org.junit.Assert.assertNotNull
@@ -28,7 +28,7 @@ import static org.junit.Assert.fail
  */
 class SpringBootMetadataReaderTests {
 
-	private final InitializrMetadata metadata = new InitializrMetadata(new InitializrConfiguration())
+	private final InitializrMetadata metadata = InitializrMetadataBuilder.create().build()
 
 	@Test
 	void readAvailableVersions() {

initializr/src/test/groovy/io/spring/initializr/test/InitializrMetadataTestBuilder.groovy

@@ -32,7 +32,7 @@ import io.spring.initializr.metadata.Type
  */
 class InitializrMetadataTestBuilder {
 
-	private final InitializrMetadataBuilder builder = new InitializrMetadataBuilder()
+	private final InitializrMetadataBuilder builder = InitializrMetadataBuilder.create()
 
 	static InitializrMetadataTestBuilder withDefaults() {
 		new InitializrMetadataTestBuilder().addDefaults()

initializr/src/test/groovy/io/spring/initializr/web/AbstractInitializrControllerIntegrationTests.groovy

@@ -16,11 +16,14 @@
 
 package io.spring.initializr.web
 
+import java.nio.charset.Charset
+
 import io.spring.initializr.metadata.DefaultMetadataElement
 import io.spring.initializr.metadata.InitializrMetadata
 import io.spring.initializr.support.DefaultInitializrMetadataProvider
 import io.spring.initializr.metadata.InitializrMetadataProvider
 import io.spring.initializr.test.ProjectAssert
+import org.json.JSONObject
 import org.junit.Rule
 import org.junit.rules.TemporaryFolder
 import org.junit.runner.RunWith
@@ -30,6 +33,7 @@ import org.springframework.boot.autoconfigure.EnableAutoConfiguration
 import org.springframework.boot.test.IntegrationTest
 import org.springframework.boot.test.SpringApplicationConfiguration
 import org.springframework.context.annotation.Bean
+import org.springframework.core.io.ClassPathResource
 import org.springframework.http.HttpEntity
 import org.springframework.http.HttpHeaders
 import org.springframework.http.HttpMethod
@@ -37,6 +41,7 @@ import org.springframework.http.MediaType
 import org.springframework.http.ResponseEntity
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner
 import org.springframework.test.context.web.WebAppConfiguration
+import org.springframework.util.StreamUtils
 import org.springframework.web.client.RestTemplate
 
 import static org.junit.Assert.assertEquals
@@ -157,6 +162,20 @@ abstract class AbstractInitializrControllerIntegrationTests {
 		archiveFile
 	}
 
+	protected JSONObject readJsonFrom(String path) {
+		def resource = new ClassPathResource(path)
+		def stream = resource.inputStream
+		try {
+			def json = StreamUtils.copyToString(stream, Charset.forName('UTF-8'))
+
+			// Let's parse the port as it is random
+			def content = json.replaceAll('@port@', String.valueOf(this.port))
+			new JSONObject(content)
+		} finally {
+			stream.close()
+		}
+	}
+
 
 	private enum ArchiveType {
 		ZIP,

initializr/src/test/groovy/io/spring/initializr/web/MainControllerIntegrationTests.groovy

@@ -449,17 +449,7 @@ class MainControllerIntegrationTests extends AbstractInitializrControllerIntegra
 	}
 
 	private JSONObject readJson(String version) {
-		def resource = new ClassPathResource("metadata/test-default-$version" + ".json")
-		def stream = resource.inputStream
-		try {
-			def json = StreamUtils.copyToString(stream, Charset.forName('UTF-8'))
-
-			// Let's parse the port as it is random
-			def content = json.replaceAll('@port@', String.valueOf(this.port))
-			new JSONObject(content)
-		} finally {
-			stream.close()
-		}
+		readJsonFrom("metadata/test-default-$version" + ".json")
 	}
 
 }

initializr/src/test/groovy/io/spring/initializr/web/MainControllerServiceMetadataIntegrationTests.groovy

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2012-2015 the original author or authors.
+ *
+ * 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 io.spring.initializr.web
+
+import io.spring.initializr.metadata.InitializrMetadata
+import io.spring.initializr.metadata.InitializrMetadataBuilder
+import io.spring.initializr.metadata.InitializrMetadataProvider
+import org.json.JSONObject
+import org.junit.Test
+import org.skyscreamer.jsonassert.JSONAssert
+import org.skyscreamer.jsonassert.JSONCompareMode
+
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.core.io.UrlResource
+import org.springframework.http.HttpStatus
+import org.springframework.http.MediaType
+import org.springframework.http.ResponseEntity
+import org.springframework.test.context.ActiveProfiles
+import org.springframework.web.client.HttpClientErrorException
+
+import static org.junit.Assert.assertEquals
+
+/**
+ * @author Stephane Nicoll
+ */
+@ActiveProfiles('test-default')
+class MainControllerServiceMetadataIntegrationTests extends AbstractInitializrControllerIntegrationTests {
+
+	@Autowired
+	private InitializrMetadataProvider metadataProvider
+
+	@Test
+	void initializeRemoteConfig() {
+		InitializrMetadata localMetadata = metadataProvider.get()
+		InitializrMetadata metadata = InitializrMetadataBuilder.create().withInitializrMetadata(
+				new UrlResource(createUrl('/metadata/service'))).build()
+		// Basic assertions
+		assertEquals(localMetadata.dependencies.content.size(), metadata.dependencies.content.size())
+		assertEquals(localMetadata.types.content.size(), metadata.types.content.size())
+		assertEquals(localMetadata.bootVersions.content.size(), metadata.bootVersions.content.size())
+		assertEquals(localMetadata.packagings.content.size(), metadata.packagings.content.size())
+		assertEquals(localMetadata.javaVersions.content.size(), metadata.javaVersions.content.size())
+		assertEquals(localMetadata.languages.content.size(), metadata.languages.content.size())
+	}
+
+	@Test
+	void textPlainNotAccepted() {
+		try {
+			execute('/metadata/service', String, null, 'text/plain')
+		} catch (HttpClientErrorException ex) {
+			assertEquals HttpStatus.NOT_ACCEPTABLE, ex.statusCode
+		}
+	}
+
+	@Test
+	void validateJson() {
+		ResponseEntity<String> response = execute('/metadata/service', String, null, 'application/json')
+		validateContentType(response, MediaType.APPLICATION_JSON)
+		JSONObject json =  new JSONObject(response.body)
+		def expected = readJsonFrom("metadata/service/test-default.json")
+		JSONAssert.assertEquals(expected, json, JSONCompareMode.STRICT)
+	}
+
+}

initializr/src/test/resources/metadata/service/test-default.json

@@ -0,0 +1,296 @@
+{
+  "artifactId": {
+    "content": "demo",
+    "description": null,
+    "id": "artifactId",
+    "type": "TEXT"
+  },
+  "bootVersions": {
+    "content": [
+      {
+        "default": false,
+        "id": "1.2.0.BUILD-SNAPSHOT",
+        "name": "Latest SNAPSHOT"
+      },
+      {
+        "default": true,
+        "id": "1.1.4.RELEASE",
+        "name": "1.1.4"
+      },
+      {
+        "default": false,
+        "id": "1.0.2.RELEASE",
+        "name": "1.0.2"
+      }
+    ],
+    "description": null,
+    "id": "bootVersion",
+    "type": "SINGLE_SELECT"
+  },
+  "configuration": {
+    "env": {
+      "artifactRepository": "https://repo.spring.io/release/",
+      "fallbackApplicationName": "Application",
+      "forceSsl": true,
+      "invalidApplicationNames": [
+        "SpringApplication",
+        "SpringBootApplication"
+      ],
+      "springBootMetadataUrl": "https://spring.io/project_metadata/spring-boot"
+    }
+  },
+  "dependencies": {
+    "content": [
+      {
+        "content": [
+          {
+            "aliases": [],
+            "artifactId": "spring-boot-starter-web",
+            "description": "Web dependency description",
+            "facets": ["web"],
+            "groupId": "org.springframework.boot",
+            "id": "web",
+            "name": "Web",
+            "scope": "compile",
+            "version": null,
+            "versionRange": null
+          },
+          {
+            "aliases": [],
+            "artifactId": "spring-boot-starter-security",
+            "description": null,
+            "facets": [],
+            "groupId": "org.springframework.boot",
+            "id": "security",
+            "name": "Security",
+            "scope": "compile",
+            "version": null,
+            "versionRange": null
+          },
+          {
+            "aliases": ["jpa"],
+            "artifactId": "spring-boot-starter-data-jpa",
+            "description": null,
+            "facets": [],
+            "groupId": "org.springframework.boot",
+            "id": "data-jpa",
+            "name": "Data JPA",
+            "scope": "compile",
+            "version": null,
+            "versionRange": null
+          }
+        ],
+        "name": "Core"
+      },
+      {
+        "content": [
+          {
+            "aliases": [],
+            "artifactId": "foo",
+            "description": null,
+            "facets": [],
+            "groupId": "org.acme",
+            "id": "org.acme:foo",
+            "name": "Foo",
+            "scope": "compile",
+            "version": "1.3.5",
+            "versionRange": null
+          },
+          {
+            "aliases": [],
+            "artifactId": "bar",
+            "description": null,
+            "facets": [],
+            "groupId": "org.acme",
+            "id": "org.acme:bar",
+            "name": "Bar",
+            "scope": "compile",
+            "version": "2.1.0",
+            "versionRange": null
+          },
+          {
+            "aliases": [],
+            "artifactId": "biz",
+            "description": null,
+            "facets": [],
+            "groupId": "org.acme",
+            "id": "org.acme:biz",
+            "name": "Biz",
+            "scope": "runtime",
+            "version": "1.3.5",
+            "versionRange": "1.2.0.BUILD-SNAPSHOT"
+          },
+          {
+            "aliases": [],
+            "artifactId": "bur",
+            "description": null,
+            "facets": [],
+            "groupId": "org.acme",
+            "id": "org.acme:bur",
+            "name": "Bur",
+            "scope": "test",
+            "version": "2.1.0",
+            "versionRange": "[1.1.4.RELEASE,1.2.0.BUILD-SNAPSHOT)"
+          },
+          {
+            "aliases": [],
+            "artifactId": "my-api",
+            "description": null,
+            "facets": [],
+            "groupId": "org.acme",
+            "id": "my-api",
+            "name": "My API",
+            "scope": "provided",
+            "version": null,
+            "versionRange": null
+          }
+        ],
+        "name": "Other"
+      }
+    ],
+    "description": null,
+    "id": "dependencies",
+    "type": "HIERARCHICAL_MULTI_SELECT"
+  },
+  "description": {
+    "content": "Demo project for Spring Boot",
+    "description": null,
+    "id": "description",
+    "type": "TEXT"
+  },
+  "groupId": {
+    "content": "org.test",
+    "description": null,
+    "id": "groupId",
+    "type": "TEXT"
+  },
+  "javaVersions": {
+    "content": [
+      {
+        "default": false,
+        "id": "1.6",
+        "name": "1.6"
+      },
+      {
+        "default": true,
+        "id": "1.7",
+        "name": "1.7"
+      },
+      {
+        "default": false,
+        "id": "1.8",
+        "name": "1.8"
+      }
+    ],
+    "description": null,
+    "id": "javaVersion",
+    "type": "SINGLE_SELECT"
+  },
+  "languages": {
+    "content": [
+      {
+        "default": false,
+        "id": "groovy",
+        "name": "Groovy"
+      },
+      {
+        "default": true,
+        "id": "java",
+        "name": "Java"
+      }
+    ],
+    "description": null,
+    "id": "language",
+    "type": "SINGLE_SELECT"
+  },
+  "name": {
+    "content": "demo",
+    "description": null,
+    "id": "name",
+    "type": "TEXT"
+  },
+  "packageName": {
+    "content": "demo",
+    "description": null,
+    "id": "packageName",
+    "type": "TEXT"
+  },
+  "packagings": {
+    "content": [
+      {
+        "default": true,
+        "id": "jar",
+        "name": "Jar"
+      },
+      {
+        "default": false,
+        "id": "war",
+        "name": "War"
+      }
+    ],
+    "description": null,
+    "id": "packaging",
+    "type": "SINGLE_SELECT"
+  },
+  "types": {
+    "content": [
+      {
+        "action": "/pom.xml",
+        "default": false,
+        "description": null,
+        "id": "maven-build",
+        "name": "Maven POM",
+        "stsId": "pom.xml",
+        "tags": {
+          "build": "maven",
+          "format": "build"
+        }
+      },
+      {
+        "action": "/starter.zip",
+        "default": true,
+        "description": null,
+        "id": "maven-project",
+        "name": "Maven Project",
+        "stsId": "starter.zip",
+        "tags": {
+          "build": "maven",
+          "format": "project"
+        }
+      },
+      {
+        "action": "/build.gradle",
+        "default": false,
+        "description": null,
+        "id": "gradle-build",
+        "name": "Gradle Config",
+        "stsId": "build.gradle",
+        "tags": {
+          "build": "gradle",
+          "format": "build"
+        }
+      },
+      {
+        "action": "/starter.zip",
+        "default": false,
+        "description": null,
+        "id": "gradle-project",
+        "name": "Gradle Project",
+        "stsId": "gradle.zip",
+        "tags": {
+          "build": "gradle",
+          "format": "project"
+        }
+      }
+    ],
+    "description": null,
+    "id": "type",
+    "type": "ACTION"
+  },
+  "version": {
+    "content": "0.0.1-SNAPSHOT",
+    "description": null,
+    "id": "version",
+    "type": "TEXT"
+  }
+}

initializr/src/test/resources/metadata/service/test-min.json

@@ -0,0 +1,143 @@
+{
+  "configuration": {
+    "env": {
+      "forceSsl": false
+    }
+  },
+  "dependencies": {
+    "id": "dependencies",
+    "type": "HIERARCHICAL_MULTI_SELECT",
+    "description": null,
+    "content": [
+      {
+        "name": "Core",
+        "content": [
+          {
+            "name": "test",
+            "id": "test",
+            "groupId": "org.springframework.boot",
+            "artifactId": "spring-boot-starter-test"
+          }
+        ]
+      }
+      ]
+  },
+  "types": {
+    "id": "type",
+    "type": "ACTION",
+    "description": null,
+    "content": [
+      {
+        "name": "Maven POM",
+        "id": "maven-build",
+        "description": null,
+        "stsId": "pom.xml",
+        "action": "/pom.xml",
+        "tags": {
+          "build": "maven",
+          "format": "build"
+        },
+        "default": false
+      }
+    ]
+  },
+  "bootVersions": {
+    "id": "bootVersion",
+    "type": "SINGLE_SELECT",
+    "description": null,
+    "content": [
+      {
+        "name": "1.1.4",
+        "id": "1.1.4.RELEASE",
+        "default": true
+      },
+      {
+        "name": "1.0.2",
+        "id": "1.0.2.RELEASE",
+        "default": false
+      }
+    ]
+  },
+  "packagings": {
+    "id": "packaging",
+    "type": "SINGLE_SELECT",
+    "description": null,
+    "content": [
+      {
+        "name": "Jar",
+        "id": "jar",
+        "default": true
+      },
+      {
+        "name": "War",
+        "id": "war",
+        "default": false
+      }
+    ]
+  },
+  "javaVersions": {
+    "id": "javaVersion",
+    "type": "SINGLE_SELECT",
+    "description": null,
+    "content": [
+      {
+        "name": "1.8",
+        "id": "1.8",
+        "default": true
+      }
+    ]
+  },
+  "languages": {
+    "id": "language",
+    "type": "SINGLE_SELECT",
+    "description": null,
+    "content": [
+      {
+        "name": "Groovy",
+        "id": "groovy",
+        "default": false
+      },
+      {
+        "name": "Java",
+        "id": "java",
+        "default": true
+      }
+    ]
+  },
+  "name": {
+    "id": "name",
+    "type": "TEXT",
+    "description": null,
+    "content": "meta-data-merge"
+  },
+  "description": {
+    "id": "description",
+    "type": "TEXT",
+    "description": null,
+    "content": "Demo project for meta-data merge"
+  },
+  "groupId": {
+    "id": "groupId",
+    "type": "TEXT",
+    "description": null,
+    "content": "org.acme"
+  },
+  "artifactId": {
+    "id": "artifactId",
+    "type": "TEXT",
+    "description": null,
+    "content": "meta-data"
+  },
+  "version": {
+    "id": "version",
+    "type": "TEXT",
+    "description": null,
+    "content": "1.0.0-SNAPSHOT"
+  },
+  "packageName": {
+    "id": "packageName",
+    "type": "TEXT",
+    "description": null,
+    "content": "org.acme.demo"
+  }
+}