Adds a new get all accessible resources endpoint for current user

Signed-off-by: Darshit Chanpura <dchanp@amazon.com>

Author: DarshitChanpura

client/src/main/java/org/opensearch/security/client/resources/ResourceSharingClient.java

@@ -12,6 +12,7 @@
 import java.util.Set;
 
 import org.opensearch.core.action.ActionListener;
+import org.opensearch.security.spi.resources.Resource;
 import org.opensearch.security.spi.resources.sharing.ResourceSharing;
 
 /**
@@ -54,4 +55,11 @@ void revokeResourceAccess(
         Set<String> scopes,
         ActionListener<ResourceSharing> listener
     );
+
+    /**
+     * Lists all resources accessible by the current user.
+     * @param resourceIndex The index containing the resources.
+     * @param listener The listener to be notified with the set of accessible resources.
+     */
+    void listAllAccessibleResources(String resourceIndex, ActionListener<Set<? extends Resource>> listener);
 }

client/src/main/java/org/opensearch/security/client/resources/ResourceSharingNodeClient.java

@@ -22,6 +22,7 @@
 import org.opensearch.security.common.resources.rest.ResourceAccessRequest;
 import org.opensearch.security.common.resources.rest.ResourceAccessResponse;
 import org.opensearch.security.common.support.ConfigConstants;
+import org.opensearch.security.spi.resources.Resource;
 import org.opensearch.security.spi.resources.sharing.ResourceSharing;
 import org.opensearch.transport.client.Client;
 
@@ -120,6 +121,26 @@ public void revokeResourceAccess(
         client.execute(ResourceAccessAction.INSTANCE, request, sharingInfoResponseListener(listener));
     }
 
+    /**
+     * Lists all resources accessible by the current user.
+     *
+     * @param listener The listener to be notified with the set of accessible resources.
+     */
+    @Override
+    public void listAllAccessibleResources(String resourceIndex, ActionListener<Set<? extends Resource>> listener) {
+        if (isResourceAccessControlDisabled("Unable to list all accessible resources.", listener)) {
+            return;
+        }
+        ResourceAccessRequest request = new ResourceAccessRequest.Builder().operation(ResourceAccessRequest.Operation.LIST)
+            .resourceIndex(resourceIndex)
+            .build();
+        client.execute(
+            ResourceAccessAction.INSTANCE,
+            request,
+            ActionListener.wrap(response -> { listener.onResponse(response.getResources()); }, listener::onFailure)
+        );
+    }
+
     /**
      * Helper method for share/revoke to check and return early is resource sharing is disabled
      * @param disabledMessage The message to be logged if resource sharing is disabled.