Create resources for namespaces

scm-core/src/main/java/sonia/scm/repository/RepositoryManager.java

@@ -24,15 +24,11 @@
 
 package sonia.scm.repository;
 
-//~--- non-JDK imports --------------------------------------------------------
-
 import sonia.scm.TypeManager;
 
 import java.io.IOException;
 import java.util.Collection;
 
-//~--- JDK imports ------------------------------------------------------------
-
 /**
  * The central class for managing {@link Repository} objects.
  * This class is a singleton and is available via injection.
@@ -49,7 +45,7 @@ public interface RepositoryManager
    * @param event hook event
    * @since 2.0.0
    */
-  public void fireHookEvent(RepositoryHookEvent event);
+  void fireHookEvent(RepositoryHookEvent event);
 
   /**
    * Imports an existing {@link Repository}.
@@ -58,9 +54,7 @@ public interface RepositoryManager
    * @param repository {@link Repository} to import
    * @throws IOException
    */
-  public void importRepository(Repository repository) throws IOException;
-
-  //~--- get methods ----------------------------------------------------------
+  void importRepository(Repository repository) throws IOException;
 
   /**
    * Returns a {@link Repository} by its namespace and name or
@@ -70,14 +64,14 @@ public interface RepositoryManager
    * @return {@link Repository} by its namespace and name or null
    * if the {@link Repository} could not be found
    */
-  public Repository get(NamespaceAndName namespaceAndName);
+  Repository get(NamespaceAndName namespaceAndName);
 
   /**
    * Returns all configured repository types.
    *
    * @return all configured repository types
    */
-  public Collection<RepositoryType> getConfiguredTypes();
+  Collection<RepositoryType> getConfiguredTypes();
 
   /**
    * Returns a {@link RepositoryHandler} by the given type (hg, git, svn ...).
@@ -86,7 +80,7 @@ public interface RepositoryManager
    * @return {@link RepositoryHandler} by the given type
    */
   @Override
-  public RepositoryHandler getHandler(String type);
+  RepositoryHandler getHandler(String type);
 
   /**
    * @param repository   the repository {@link Repository}
@@ -94,5 +88,12 @@ public interface RepositoryManager
    * @param newName      the new repository name
    * @return {@link Repository} the renamed repository
    */
-  public Repository rename(Repository repository, String newNameSpace, String newName);
+  Repository rename(Repository repository, String newNameSpace, String newName);
+
+  /**
+   * Returns all namespaces.
+   *
+   * @return all namespaces
+   */
+  Collection<String> getAllNamespaces();
 }

scm-core/src/main/java/sonia/scm/repository/RepositoryManagerDecorator.java

@@ -131,6 +131,11 @@ public class RepositoryManagerDecorator
     return decorated.rename(repository, newNamespace, newName);
   }
 
+  @Override
+  public Collection<String> getAllNamespaces() {
+    return decorated.getAllNamespaces();
+  }
+
   //~--- fields ---------------------------------------------------------------
 
   /**

scm-core/src/main/java/sonia/scm/web/VndMediaType.java

@@ -44,6 +44,7 @@ public class VndMediaType {
   public static final String GROUP = PREFIX + "group" + SUFFIX;
   public static final String AUTOCOMPLETE =  PREFIX + "autocomplete" + SUFFIX;
   public static final String REPOSITORY = PREFIX + "repository" + SUFFIX;
+  public static final String NAMESPACE = PREFIX + "namespace" + SUFFIX;
   public static final String REPOSITORY_PERMISSION = PREFIX + "repositoryPermission" + SUFFIX;
   public static final String CHANGESET = PREFIX + "changeset" + SUFFIX;
   public static final String CHANGESET_COLLECTION = PREFIX + "changesetCollection" + SUFFIX;
@@ -57,6 +58,7 @@ public class VndMediaType {
   public static final String USER_COLLECTION = PREFIX + "userCollection" + SUFFIX;
   public static final String GROUP_COLLECTION = PREFIX + "groupCollection" + SUFFIX;
   public static final String REPOSITORY_COLLECTION = PREFIX + "repositoryCollection" + SUFFIX;
+  public static final String NAMESPACE_COLLECTION = PREFIX + "namespaceCollection" + SUFFIX;
   public static final String BRANCH_COLLECTION = PREFIX + "branchCollection" + SUFFIX;
   public static final String CONFIG = PREFIX + "config" + SUFFIX;
   public static final String REPOSITORY_VERB_COLLECTION = PREFIX + "repositoryVerbCollection" + SUFFIX;

scm-webapp/src/main/java/sonia/scm/api/v2/resources/NamespaceCollectionResource.java

@@ -0,0 +1,77 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.api.v2.resources;
+
+import de.otto.edison.hal.HalRepresentation;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import sonia.scm.repository.RepositoryManager;
+import sonia.scm.web.VndMediaType;
+
+import javax.inject.Inject;
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+
+public class NamespaceCollectionResource {
+
+  private final RepositoryManager manager;
+  private final NamespaceCollectionToDtoMapper repositoryCollectionToDtoMapper;
+
+  @Inject
+  public NamespaceCollectionResource(RepositoryManager manager, NamespaceCollectionToDtoMapper repositoryCollectionToDtoMapper) {
+    this.manager = manager;
+    this.repositoryCollectionToDtoMapper = repositoryCollectionToDtoMapper;
+  }
+
+  /**
+   * Returns all namespaces.
+   */
+  @GET
+  @Path("")
+  @Produces(VndMediaType.NAMESPACE_COLLECTION)
+  @Operation(summary = "List of namespaces", description = "Returns all namespaces.", tags = "Namespace")
+  @ApiResponse(
+    responseCode = "200",
+    description = "success",
+    content = @Content(
+      mediaType = VndMediaType.NAMESPACE_COLLECTION,
+      schema = @Schema(implementation = CollectionDto.class)
+    )
+  )
+  @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
+  @ApiResponse(
+    responseCode = "500",
+    description = "internal server error",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
+  public HalRepresentation getAll() {
+    return repositoryCollectionToDtoMapper.map(manager.getAllNamespaces());
+  }
+}

scm-webapp/src/main/java/sonia/scm/api/v2/resources/NamespaceCollectionToDtoMapper.java

@@ -0,0 +1,57 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.api.v2.resources;
+
+import de.otto.edison.hal.Embedded;
+import de.otto.edison.hal.HalRepresentation;
+
+import javax.inject.Inject;
+import java.util.Collection;
+
+import static de.otto.edison.hal.Embedded.embeddedBuilder;
+import static de.otto.edison.hal.Links.linkingTo;
+import static java.util.stream.Collectors.toList;
+
+public class NamespaceCollectionToDtoMapper {
+
+  private final NamespaceToNamespaceDtoMapper namespaceMapper;
+  private final ResourceLinks links;
+
+  @Inject
+  public NamespaceCollectionToDtoMapper(NamespaceToNamespaceDtoMapper namespaceMapper, ResourceLinks links) {
+    this.namespaceMapper = namespaceMapper;
+    this.links = links;
+  }
+
+  public HalRepresentation map(Collection<String> namespaces) {
+    Embedded namespaceDtos = embeddedBuilder()
+      .with("namespaces", namespaces.stream().map(namespaceMapper::map).collect(toList()))
+      .build();
+    return new HalRepresentation(
+      linkingTo().self(links.namespaceCollection().self()).build(),
+      namespaceDtos
+    );
+  }
+}

scm-webapp/src/main/java/sonia/scm/api/v2/resources/NamespaceDto.java

@@ -0,0 +1,42 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.api.v2.resources;
+
+import de.otto.edison.hal.HalRepresentation;
+import de.otto.edison.hal.Links;
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class NamespaceDto extends HalRepresentation {
+
+  private String namespace;
+
+  public NamespaceDto(String namespace, Links links) {
+    super(links);
+    this.namespace = namespace;
+  }
+}

scm-webapp/src/main/java/sonia/scm/api/v2/resources/NamespaceResource.java

@@ -0,0 +1,100 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.api.v2.resources;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import sonia.scm.repository.RepositoryManager;
+import sonia.scm.web.VndMediaType;
+
+import javax.inject.Inject;
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.Produces;
+
+import static sonia.scm.ContextEntry.ContextBuilder.entity;
+import static sonia.scm.NotFoundException.notFound;
+
+public class NamespaceResource {
+
+  private final RepositoryManager manager;
+  private final NamespaceToNamespaceDtoMapper namespaceMapper;
+
+  @Inject
+  public NamespaceResource(RepositoryManager manager, NamespaceToNamespaceDtoMapper namespaceMapper) {
+    this.manager = manager;
+    this.namespaceMapper = namespaceMapper;
+  }
+
+  /**
+   * Returns a namespace.
+   *
+   * @param namespace the requested namespace
+   */
+  @GET
+  @Path("")
+  @Produces(VndMediaType.NAMESPACE)
+  @Operation(summary = "Get single namespace", description = "Returns the namespace for the given name.", tags = "Namespace")
+  @ApiResponse(
+    responseCode = "200",
+    description = "success",
+    content = @Content(
+      mediaType = VndMediaType.NAMESPACE,
+      schema = @Schema(implementation = NamespaceDto.class)
+    )
+  )
+  @ApiResponse(
+    responseCode = "401",
+    description = "not authenticated / invalid credentials"
+  )
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, no namespace with the specified name available",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    )
+  )
+  @ApiResponse(
+    responseCode = "500",
+    description = "internal server error",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    )
+  )
+  public NamespaceDto get(@PathParam("namespace") String namespace) {
+    return manager.getAllNamespaces()
+      .stream()
+      .filter(n -> n.equals(namespace))
+      .map(namespaceMapper::map)
+      .findFirst()
+      .orElseThrow(() -> notFound(entity("Namespace", namespace)));
+  }
+
+}

scm-webapp/src/main/java/sonia/scm/api/v2/resources/NamespaceRootResource.java

@@ -0,0 +1,64 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.api.v2.resources;
+
+import io.swagger.v3.oas.annotations.OpenAPIDefinition;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import javax.inject.Inject;
+import javax.inject.Provider;
+import javax.ws.rs.Path;
+
+/**
+ * RESTful Web Service Resource to manage namespaces.
+ */
+@OpenAPIDefinition(
+  tags = {
+    @Tag(name = "Namespace", description = "Namespace related endpoints")
+  }
+)
+@Path(NamespaceRootResource.NAMESPACE_PATH_V2)
+public class NamespaceRootResource {
+  static final String NAMESPACE_PATH_V2 = "v2/namespaces/";
+
+  private final Provider<NamespaceCollectionResource> namespaceCollectionResource;
+  private final Provider<NamespaceResource> namespaceResource;
+
+  @Inject
+  public NamespaceRootResource(Provider<NamespaceCollectionResource> namespaceCollectionResource, Provider<NamespaceResource> namespaceResource) {
+    this.namespaceCollectionResource = namespaceCollectionResource;
+    this.namespaceResource = namespaceResource;
+  }
+
+  @Path("{namespace}")
+  public NamespaceResource getNamespaceResource() {
+    return namespaceResource.get();
+  }
+
+  @Path("")
+  public NamespaceCollectionResource getNamespaceCollectionResource() {
+    return namespaceCollectionResource.get();
+  }
+}

scm-webapp/src/main/java/sonia/scm/api/v2/resources/NamespaceStrategyResource.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.api.v2.resources;
 
 import de.otto.edison.hal.Links;
@@ -48,8 +48,8 @@ public class NamespaceStrategyResource {
 
   static final String PATH = "v2/namespaceStrategies";
 
-  private Set<NamespaceStrategy> namespaceStrategies;
-  private Provider<NamespaceStrategy> namespaceStrategyProvider;
+  private final Set<NamespaceStrategy> namespaceStrategies;
+  private final Provider<NamespaceStrategy> namespaceStrategyProvider;
 
   @Inject
   public NamespaceStrategyResource(Set<NamespaceStrategy> namespaceStrategies, Provider<NamespaceStrategy> namespaceStrategyProvider) {

scm-webapp/src/main/java/sonia/scm/api/v2/resources/NamespaceToNamespaceDtoMapper.java

@@ -0,0 +1,43 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.api.v2.resources;
+
+import javax.inject.Inject;
+
+import static de.otto.edison.hal.Links.linkingTo;
+
+class NamespaceToNamespaceDtoMapper {
+
+  private final ResourceLinks links;
+
+  @Inject
+  NamespaceToNamespaceDtoMapper(ResourceLinks links) {
+    this.links = links;
+  }
+
+  NamespaceDto map(String namespace) {
+    return new NamespaceDto(namespace, linkingTo().self(links.namespace().self(namespace)).build());
+  }
+}

scm-webapp/src/main/java/sonia/scm/api/v2/resources/ResourceLinks.java

@@ -876,4 +876,36 @@ class ResourceLinks {
       return permissionsLinkBuilder.method("getAll").parameters().href();
     }
   }
+
+  public NamespaceCollectionLinks namespaceCollection() {
+    return new NamespaceCollectionLinks(scmPathInfoStore.get());
+  }
+
+  static class NamespaceCollectionLinks {
+    private final LinkBuilder namespaceCollectionLinkBuilder;
+
+    NamespaceCollectionLinks(ScmPathInfo scmPathInfo) {
+      this.namespaceCollectionLinkBuilder = new LinkBuilder(scmPathInfo, NamespaceRootResource.class, NamespaceCollectionResource.class);
+    }
+
+    String self() {
+      return namespaceCollectionLinkBuilder.method("getNamespaceCollectionResource").parameters().method("getAll").parameters().href();
+    }
+  }
+
+  public NamespaceLinks namespace() {
+    return new NamespaceLinks(scmPathInfoStore.get());
+  }
+
+  static class NamespaceLinks {
+    private final LinkBuilder namespaceLinkBuilder;
+
+    NamespaceLinks(ScmPathInfo scmPathInfo) {
+      this.namespaceLinkBuilder = new LinkBuilder(scmPathInfo, NamespaceRootResource.class, NamespaceResource.class);
+    }
+
+    String self(String namespace) {
+      return namespaceLinkBuilder.method("getNamespaceResource").parameters().method("get").parameters(namespace).href();
+    }
+  }
 }

scm-webapp/src/main/java/sonia/scm/repository/DefaultRepositoryManager.java

@@ -61,6 +61,7 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.ThreadFactory;
 import java.util.function.Predicate;
 
+import static java.util.stream.Collectors.toSet;
 import static sonia.scm.AlreadyExistsException.alreadyExists;
 import static sonia.scm.ContextEntry.ContextBuilder.entity;
 import static sonia.scm.NotFoundException.notFound;
@@ -330,6 +331,13 @@ public class DefaultRepositoryManager extends AbstractRepositoryManager {
     return getAll(null, start, limit);
   }
 
+  @Override
+  public Collection<String> getAllNamespaces() {
+    return getAll().stream()
+      .map(Repository::getNamespace)
+      .collect(toSet());
+  }
+
   @Override
   public Collection<RepositoryType> getConfiguredTypes() {
     List<RepositoryType> validTypes = Lists.newArrayList();

scm-webapp/src/test/java/sonia/scm/api/v2/resources/NamespaceRootResourceTest.java

@@ -0,0 +1,106 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.api.v2.resources;
+
+import org.jboss.resteasy.mock.MockHttpRequest;
+import org.jboss.resteasy.mock.MockHttpResponse;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import sonia.scm.repository.RepositoryManager;
+import sonia.scm.web.RestDispatcher;
+
+import java.io.UnsupportedEncodingException;
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import static com.google.inject.util.Providers.of;
+import static java.util.Arrays.asList;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class NamespaceRootResourceTest {
+
+  @Mock
+  RepositoryManager repositoryManager;
+
+  RestDispatcher dispatcher = new RestDispatcher();
+  MockHttpResponse response = new MockHttpResponse();
+
+  ResourceLinks links = ResourceLinksMock.createMock(URI.create("/"));
+
+  @BeforeEach
+  void setUpResources() {
+    NamespaceToNamespaceDtoMapper namespaceMapper = new NamespaceToNamespaceDtoMapper(links);
+    NamespaceCollectionToDtoMapper namespaceCollectionToDtoMapper = new NamespaceCollectionToDtoMapper(namespaceMapper, links);
+    NamespaceCollectionResource namespaceCollectionResource = new NamespaceCollectionResource(repositoryManager, namespaceCollectionToDtoMapper);
+    NamespaceResource namespaceResource = new NamespaceResource(repositoryManager, namespaceMapper);
+    dispatcher.addSingletonResource(new NamespaceRootResource(of(namespaceCollectionResource), of(namespaceResource)));
+  }
+
+  @Test
+  void shouldReturnAllNamespaces() throws URISyntaxException, UnsupportedEncodingException {
+    when(repositoryManager.getAllNamespaces()).thenReturn(asList("hitchhiker", "space"));
+
+    MockHttpRequest request = MockHttpRequest.get("/" + NamespaceRootResource.NAMESPACE_PATH_V2);
+
+    dispatcher.invoke(request, response);
+
+    assertThat(response.getStatus()).isEqualTo(200);
+    assertThat(response.getContentAsString())
+      .contains("\"self\":{\"href\":\"/v2/namespaces/\"}")
+      .contains("\"_embedded\"")
+      .contains("\"namespace\":\"hitchhiker\"")
+      .contains("\"namespace\":\"space\"");
+  }
+
+  @Test
+  void shouldReturnSingleNamespace() throws URISyntaxException, UnsupportedEncodingException {
+    when(repositoryManager.getAllNamespaces()).thenReturn(asList("hitchhiker", "space"));
+
+    MockHttpRequest request = MockHttpRequest.get("/" + NamespaceRootResource.NAMESPACE_PATH_V2 + "space");
+
+    dispatcher.invoke(request, response);
+
+    assertThat(response.getStatus()).isEqualTo(200);
+    assertThat(response.getContentAsString())
+      .contains("\"namespace\":\"space\"")
+      .contains("\"self\":{\"href\":\"/v2/namespaces/space\"}");
+  }
+
+  @Test
+  void shouldHandleUnknownNamespace() throws URISyntaxException, UnsupportedEncodingException {
+    when(repositoryManager.getAllNamespaces()).thenReturn(asList("hitchhiker", "space"));
+
+    MockHttpRequest request = MockHttpRequest.get("/" + NamespaceRootResource.NAMESPACE_PATH_V2 + "unknown");
+
+    dispatcher.invoke(request, response);
+
+    assertThat(response.getStatus()).isEqualTo(404);
+  }
+}

scm-webapp/src/test/java/sonia/scm/api/v2/resources/ResourceLinksMock.java

@@ -76,6 +76,8 @@ public class ResourceLinksMock {
     lenient().when(resourceLinks.repositoryRoleCollection()).thenReturn(new ResourceLinks.RepositoryRoleCollectionLinks(pathInfo));
     lenient().when(resourceLinks.namespaceStrategies()).thenReturn(new ResourceLinks.NamespaceStrategiesLinks(pathInfo));
     lenient().when(resourceLinks.annotate()).thenReturn(new ResourceLinks.AnnotateLinks(pathInfo));
+    lenient().when(resourceLinks.namespace()).thenReturn(new ResourceLinks.NamespaceLinks(pathInfo));
+    lenient().when(resourceLinks.namespaceCollection()).thenReturn(new ResourceLinks.NamespaceCollectionLinks(pathInfo));
 
     return resourceLinks;
   }

scm-webapp/src/test/java/sonia/scm/repository/DefaultRepositoryManagerTest.java

@@ -33,6 +33,7 @@ import com.google.common.collect.ImmutableSet;
 import com.google.inject.util.Providers;
 import org.apache.shiro.authz.UnauthorizedException;
 import org.apache.shiro.util.ThreadContext;
+import org.assertj.core.api.Assertions;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -444,6 +445,18 @@ public class DefaultRepositoryManagerTest extends ManagerTestBase<Repository> {
     assertEquals("hitchhiker", changedRepo.getNamespace());
   }
 
+  @Test
+  public void shouldReturnDistinctNamespaces() {
+    createTestRepository();
+    createSecondTestRepository();
+
+    Collection<String> namespaces = ((RepositoryManager) manager).getAllNamespaces();
+
+    Assertions.assertThat(namespaces)
+      .hasSize(1)
+      .contains("default_namespace");
+  }
+
   //~--- methods --------------------------------------------------------------
 
   @Override