Actionize the EPP endpoints.

This introduces Actions and Dagger up until FlowRunner. The changes
to the servlets are relatively simple, but the required changes to
the tests, as well as to auxillary EPP endpoints (such as the http
check api and the load test servlet) were vast. I've added some
comments in critique to make the review easier that don't really
make sense as in-code comments for the future.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=124593546

java/google/registry/ui/server/api/CheckApiAction.java

@@ -0,0 +1,165 @@
+// Copyright 2016 The Domain Registry 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.ui.server.api;
+
+import static com.google.common.base.MoreObjects.firstNonNull;
+import static com.google.common.base.Strings.nullToEmpty;
+import static com.google.common.net.HttpHeaders.ACCESS_CONTROL_ALLOW_ORIGIN;
+import static google.registry.model.eppcommon.ProtocolDefinition.ServiceExtension.FEE_0_6;
+import static google.registry.model.registry.Registries.findTldForNameOrThrow;
+import static google.registry.ui.server.SoyTemplateUtils.createTofuSupplier;
+import static google.registry.util.DomainNameUtils.canonicalizeDomainName;
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.json.simple.JSONValue.toJSONString;
+
+import com.google.common.base.Supplier;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.net.InternetDomainName;
+import com.google.common.net.MediaType;
+import com.google.template.soy.tofu.SoyTofu;
+
+import dagger.Module;
+import dagger.Provides;
+
+import google.registry.config.RegistryEnvironment;
+import google.registry.flows.EppException;
+import google.registry.flows.EppXmlTransformer;
+import google.registry.flows.FlowRunner;
+import google.registry.flows.FlowRunner.CommitMode;
+import google.registry.flows.FlowRunner.UserPrivileges;
+import google.registry.flows.SessionMetadata.SessionSource;
+import google.registry.flows.StatelessRequestSessionMetadata;
+import google.registry.flows.domain.DomainCheckFlow;
+import google.registry.model.domain.fee.FeeCheckResponseExtension;
+import google.registry.model.domain.fee.FeeCheckResponseExtension.FeeCheck;
+import google.registry.model.eppcommon.Trid;
+import google.registry.model.eppinput.EppInput;
+import google.registry.model.eppoutput.CheckData.DomainCheck;
+import google.registry.model.eppoutput.CheckData.DomainCheckData;
+import google.registry.model.eppoutput.Response;
+import google.registry.request.Action;
+import google.registry.request.Parameter;
+import google.registry.request.RequestParameters;
+import google.registry.ui.soy.api.DomainCheckFeeEppSoyInfo;
+import google.registry.util.Clock;
+import google.registry.util.FormattingLogger;
+
+import java.util.Map;
+
+import javax.inject.Inject;
+import javax.servlet.http.HttpServletRequest;
+
+/**
+ * A servlet that returns availability and premium checks as json.
+ *
+ * <p>This action returns plain JSON without a safety prefix, so it's vital that the output not be
+ * user controlled, lest it open an XSS vector. Do not modify this to return the domain name in the
+ * response.
+ */
+@Action(path = "/check")
+public class CheckApiAction implements Runnable {
+
+  private static final FormattingLogger logger = FormattingLogger.getLoggerForCallerClass();
+
+  private static final Supplier<SoyTofu> TOFU_SUPPLIER =
+      createTofuSupplier(DomainCheckFeeEppSoyInfo.getInstance());
+
+  private StatelessRequestSessionMetadata sessionMetadata = new StatelessRequestSessionMetadata(
+      RegistryEnvironment.get().config().getCheckApiServletRegistrarClientId(),
+      false,
+      false,
+      ImmutableSet.of(FEE_0_6.getUri()),
+      SessionSource.HTTP);
+
+  @Inject @Parameter("domain") String domain;
+  @Inject google.registry.request.Response response;
+  @Inject Clock clock;
+  @Inject CheckApiAction() {}
+
+  @Override
+  public void run() {
+    Map<String, ?> checkResponse = doCheck(domain);
+    response.setHeader("Content-Disposition", "attachment");
+    response.setHeader("X-Content-Type-Options", "nosniff");
+    response.setHeader(ACCESS_CONTROL_ALLOW_ORIGIN, "*");
+    response.setContentType(MediaType.JSON_UTF_8);
+    response.setPayload(toJSONString(checkResponse));
+  }
+
+  // TODO(rgr): add whitebox instrumentation for this?
+  private Map<String, ?> doCheck(String domainString) {
+    try {
+      domainString = canonicalizeDomainName(nullToEmpty(domainString));
+      // Validate the TLD.
+      findTldForNameOrThrow(InternetDomainName.from(domainString));
+    } catch (IllegalStateException | IllegalArgumentException e) {
+      return fail("Must supply a valid domain name on an authoritative TLD");
+    }
+    try {
+      byte[] inputXmlBytes = TOFU_SUPPLIER.get()
+          .newRenderer(DomainCheckFeeEppSoyInfo.DOMAINCHECKFEE)
+          .setData(ImmutableMap.of("domainName", domainString))
+          .render()
+          .getBytes(UTF_8);
+      Response response = new FlowRunner(
+          DomainCheckFlow.class,
+          EppXmlTransformer.<EppInput>unmarshal(inputXmlBytes),
+          Trid.create(getClass().getSimpleName()),
+          sessionMetadata,
+          inputXmlBytes,
+          null,
+          clock)
+              .run(CommitMode.LIVE, UserPrivileges.NORMAL)
+              .getResponse();
+      DomainCheckData checkData = (DomainCheckData) response.getResponseData().get(0);
+      DomainCheck check = (DomainCheck) checkData.getChecks().get(0);
+      boolean available = check.getName().getAvail();
+      ImmutableMap.Builder<String, Object> builder = new ImmutableMap.Builder<String, Object>()
+          .put("status", "success")
+          .put("available", available);
+      if (available) {
+        FeeCheckResponseExtension feeCheckResponse =
+            (FeeCheckResponseExtension) response.getExtensions().get(0);
+        FeeCheck feeCheck = feeCheckResponse.getChecks().get(0);
+        builder.put("tier", firstNonNull(feeCheck.getFeeClass(), "standard"));
+      } else {
+        builder.put("reason", check.getReason());
+      }
+      return builder.build();
+    } catch (EppException e) {
+      return fail(e.getMessage());
+    } catch (Exception e) {
+      logger.warning(e, "Unknown error");
+      return fail("Invalid request");
+    }
+  }
+
+  private Map<String, String> fail(String reason) {
+    return ImmutableMap.of(
+        "status", "error",
+        "reason", reason);
+  }
+
+  /** Dagger module for the check api endpoint. */
+  @Module
+  public static final class CheckApiModule {
+    @Provides
+    @Parameter("domain")
+    static String provideDomain(HttpServletRequest req) {
+      return RequestParameters.extractRequiredParameter(req, "domain");
+    }
+  }
+}