Issue 53: Allow namespace as a path param (#54)

Signed-off-by: Shivesh Ranjan <[email protected]>

server/src/main/java/io/pravega/schemaregistry/server/rest/RestServer.java

@@ -19,6 +19,7 @@
 import javax.ws.rs.core.UriBuilder;
 
 import io.pravega.common.security.JKSHelper;
+import io.pravega.schemaregistry.server.rest.filter.NamespaceRedirectFilter;
 import io.pravega.schemaregistry.server.rest.resources.GroupResourceImpl;
 import io.pravega.schemaregistry.server.rest.resources.PingImpl;
 import io.pravega.schemaregistry.server.rest.resources.SchemaResourceImpl;
@@ -49,6 +50,7 @@ public RestServer(SchemaRegistryService registryService, ServiceConfig restServe
         this.baseUri = UriBuilder.fromUri("http://" + restServerConfig.getHost()).port(restServerConfig.getPort()).build();
 
         final Set<Object> resourceObjs = new HashSet<>();
+        resourceObjs.add(new NamespaceRedirectFilter());
         resourceObjs.add(new PingImpl());
         resourceObjs.add(new GroupResourceImpl(registryService, restServerConfig, executor()));
         resourceObjs.add(new SchemaResourceImpl(registryService, restServerConfig, executor()));

server/src/main/java/io/pravega/schemaregistry/server/rest/filter/NamespaceRedirectFilter.java

@@ -0,0 +1,70 @@
+/**
+ * Copyright (c) Dell Inc., or its subsidiaries. All Rights Reserved.
+ * <p>
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ */
+package io.pravega.schemaregistry.server.rest.filter;
+
+import javax.ws.rs.WebApplicationException;
+import javax.ws.rs.container.ContainerRequestContext;
+import javax.ws.rs.container.ContainerRequestFilter;
+import javax.ws.rs.container.PreMatching;
+import javax.ws.rs.core.PathSegment;
+import javax.ws.rs.core.UriBuilder;
+import javax.ws.rs.core.UriInfo;
+import javax.ws.rs.ext.Provider;
+import java.util.List;
+
+/**
+ * A request filter that converts namespace expressed as a path param into a query param. 
+ * 
+ * This allows users to express either "/v1/namespace/ns/groups" "/v1/groups?namespace=ns" and both are equivalent. 
+ * 
+ * If both path param and query param are used to supply values for namespace, then the path param overrides the query param. 
+ * So if someone expresses the uri as "/v1/namespace/ns1/groups?namespace=ns2". This will result in namespace being 
+ * set to ns1 for the request.  
+ */
+@Provider
+@PreMatching
+public class NamespaceRedirectFilter implements ContainerRequestFilter {
+    private static final String NAMESPACE = "namespace";
+    private static final String GROUPS = "groups";
+
+    @Override
+    public void filter(ContainerRequestContext containerRequest)
+            throws WebApplicationException {
+        UriInfo uriInfo = containerRequest.getUriInfo();
+        UriBuilder uriBuilder = uriInfo.getRequestUriBuilder();
+        List<PathSegment> pathSegments = uriInfo.getPathSegments();
+        // if path has namespace defined as path segment. convert it to query param. 
+        // namespace path param is converted to query param only when namespace name is followed by groups path segment.
+        if (pathSegments.size() > 3 && pathSegments.get(1).getPath().equals(NAMESPACE) 
+                && pathSegments.get(3).getPath().equals(GROUPS)) {
+            handleNamespacePath(uriBuilder, pathSegments);
+        }
+        containerRequest.setRequestUri(uriBuilder.build());
+    }
+
+    private void handleNamespacePath(UriBuilder uriBuilder, List<PathSegment> pathSegments) {
+        StringBuilder pathBuilder = new StringBuilder();
+        appendPath(pathSegments.get(0), pathBuilder);
+        // pathsegments(1) is namspace and pathsegments(2) is name of the namespace. 
+        String namespace = pathSegments.get(2).getPath();
+
+        for (int i = 3; i < pathSegments.size(); i++) {
+            appendPath(pathSegments.get(i), pathBuilder);
+        }
+
+        uriBuilder.replacePath(pathBuilder.toString());
+        uriBuilder.replaceQueryParam(NAMESPACE, namespace);
+    }
+
+    private void appendPath(PathSegment pathSegment, StringBuilder pathBuilder) {
+        pathBuilder.append("/").append(pathSegment.getPath());
+        pathSegment.getMatrixParameters().forEach((x, y) -> pathBuilder.append(";").append(x).append("=").append(y));
+    }
+}

server/src/test/java/io/pravega/schemaregistry/server/rest/resources/SchemaRegistryResourceTest.java

@@ -20,6 +20,7 @@
 import io.pravega.schemaregistry.contract.transform.ModelHelper;
 import io.pravega.schemaregistry.server.rest.RegistryApplication;
 import io.pravega.schemaregistry.server.rest.ServiceConfig;
+import io.pravega.schemaregistry.server.rest.filter.NamespaceRedirectFilter;
 import io.pravega.schemaregistry.service.SchemaRegistryService;
 import org.glassfish.jersey.test.JerseyTest;
 import org.glassfish.jersey.test.TestProperties;
@@ -50,6 +51,7 @@
 
 public class SchemaRegistryResourceTest extends JerseyTest {
     private static final String GROUPS = "v1/groups";
+    private static final String NAMESPACE_FORMAT = "v1/namespace/%s/groups";
     private SchemaRegistryService service;
     private ScheduledExecutorService executor;
 
@@ -59,6 +61,7 @@ protected Application configure() {
         forceSet(TestProperties.CONTAINER_PORT, "0");
         service = mock(SchemaRegistryService.class);
         final Set<Object> resourceObjs = new HashSet<>();
+        resourceObjs.add(new NamespaceRedirectFilter());
         resourceObjs.add(new GroupResourceImpl(service, ServiceConfig.builder().build(), executor));
         resourceObjs.add(new SchemaResourceImpl(service, ServiceConfig.builder().build(), executor));
 
@@ -86,6 +89,12 @@ public void groups() throws ExecutionException, InterruptedException {
         assertEquals(response.getStatus(), 200);
         ListGroupsResponse list = response.readEntity(ListGroupsResponse.class);
         assertEquals(list.getGroups().size(), 1);
+
+        future = target(String.format(NAMESPACE_FORMAT, "ns")).queryParam("limit", 100).request().async().get();
+        response = future.get();
+        assertEquals(response.getStatus(), 200);
+        list = response.readEntity(ListGroupsResponse.class);
+        assertEquals(list.getGroups().size(), 1);
 
         // region create group
         // endregion