Add mapreduce to delete load test data

This hard-deletes all contacts and hosts owned by a specific set of registrar
client IDs, currently just "proxy".

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=192325211

java/google/registry/batch/DeleteLoadTestDataAction.java

@@ -0,0 +1,148 @@
+// Copyright 2018 The Nomulus Authors. All Rights Reserved.
+//
+// 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 google.registry.batch;
+
+import static com.google.common.base.Preconditions.checkState;
+import static google.registry.config.RegistryEnvironment.PRODUCTION;
+import static google.registry.mapreduce.MapreduceRunner.PARAM_DRY_RUN;
+import static google.registry.mapreduce.inputs.EppResourceInputs.createEntityInput;
+import static google.registry.model.ofy.ObjectifyService.ofy;
+import static google.registry.request.Action.Method.POST;
+
+import com.google.appengine.tools.mapreduce.Mapper;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.googlecode.objectify.Key;
+import google.registry.config.RegistryEnvironment;
+import google.registry.mapreduce.MapreduceRunner;
+import google.registry.model.EppResource;
+import google.registry.model.contact.ContactResource;
+import google.registry.model.host.HostResource;
+import google.registry.model.index.EppResourceIndex;
+import google.registry.model.index.ForeignKeyIndex;
+import google.registry.request.Action;
+import google.registry.request.Parameter;
+import google.registry.request.Response;
+import google.registry.request.auth.Auth;
+import google.registry.util.FormattingLogger;
+import google.registry.util.PipelineUtils;
+import java.util.List;
+import javax.inject.Inject;
+
+/**
+ * Hard deletes load-test ContactResources, HostResources, their subordinate history entries, and
+ * the associated ForeignKey and EppResourceIndex entities.
+ *
+ * <p>This only deletes contacts and hosts, NOT domains. To delete domains, use
+ * {@link DeleteLoadTestDataAction} and pass it the TLD(s) that the load test domains were created
+ * on. Note that DeleteLoadTestDataAction is safe enough to run in production whereas this mapreduce
+ * is not, but this one does not need to be runnable in production because load testing isn't run
+ * against production.
+ */
+@Action(path = "/_dr/task/deleteLoadTestData", method = POST, auth = Auth.AUTH_INTERNAL_ONLY)
+public class DeleteLoadTestDataAction implements Runnable {
+
+  private static final FormattingLogger logger = FormattingLogger.getLoggerForCallerClass();
+
+  /**
+   * The registrars for which to wipe out all contacts/hosts.
+   *
+   * <p>This is hard-coded because it's too dangerous to specify as a request parameter. By putting
+   * it in code it always has to go through code review.
+   */
+  private static final ImmutableSet<String> LOAD_TEST_REGISTRARS = ImmutableSet.of("proxy");
+
+  @Inject
+  @Parameter(PARAM_DRY_RUN)
+  boolean isDryRun;
+
+  @Inject MapreduceRunner mrRunner;
+  @Inject Response response;
+  @Inject RegistryEnvironment registryEnvironment;
+
+  @Inject
+  DeleteLoadTestDataAction() {}
+
+  @Override
+  public void run() {
+    // This mapreduce doesn't guarantee that foreign key relations are preserved, so isn't safe to
+    // run on production. On other environments, data is fully wiped out occasionally anyway, so
+    // having some broken data that isn't referred to isn't the end of the world.
+    checkState(
+        registryEnvironment != PRODUCTION, "This mapreduce is not safe to run on PRODUCTION.");
+
+    response.sendJavaScriptRedirect(
+        PipelineUtils.createJobPath(
+            mrRunner
+                .setJobName("Delete load test data")
+                .setModuleName("backend")
+                .runMapOnly(
+                    new DeleteLoadTestDataMapper(isDryRun),
+                    ImmutableList.of(
+                        createEntityInput(ContactResource.class),
+                        createEntityInput(HostResource.class)))));
+  }
+
+  /** Provides the map method that runs for each existing contact and host entity. */
+  public static class DeleteLoadTestDataMapper extends Mapper<EppResource, Void, Void> {
+
+    private static final long serialVersionUID = -3817710674062432694L;
+
+    private final boolean isDryRun;
+
+    public DeleteLoadTestDataMapper(boolean isDryRun) {
+      this.isDryRun = isDryRun;
+    }
+
+    @Override
+    public final void map(EppResource resource) {
+      if (LOAD_TEST_REGISTRARS.contains(resource.getPersistedCurrentSponsorClientId())) {
+        deleteResource(resource);
+        getContext()
+            .incrementCounter(
+                String.format("deleted %s entities", resource.getClass().getSimpleName()));
+      } else {
+        getContext().incrementCounter("skipped, not load test data");
+      }
+    }
+
+    private void deleteResource(EppResource resource) {
+      final Key<EppResourceIndex> eppIndex =
+          Key.create(EppResourceIndex.create(Key.create(resource)));
+      final Key<? extends ForeignKeyIndex<?>> fki = ForeignKeyIndex.createKey(resource);
+      int numEntitiesDeleted =
+          ofy()
+              .transact(
+                  () -> {
+                    // This ancestor query selects all descendant entities.
+                    List<Key<Object>> resourceAndDependentKeys =
+                        ofy().load().ancestor(resource).keys().list();
+                    ImmutableSet<Key<?>> allKeys =
+                        new ImmutableSet.Builder<Key<?>>()
+                            .add(fki)
+                            .add(eppIndex)
+                            .addAll(resourceAndDependentKeys)
+                            .build();
+                    if (isDryRun) {
+                      logger.infofmt("Would hard-delete the following entities: %s", allKeys);
+                    } else {
+                      ofy().deleteWithoutBackup().keys(allKeys);
+                    }
+                    return allKeys.size();
+                  });
+      getContext().incrementCounter("total entities deleted", numEntitiesDeleted);
+    }
+  }
+}