Add publish functionality to billing pipeline

This closes the end-to-end billing pipeline, allowing us to share generated detail reports with registrars via Drive and e-mail the invoicing team a link to the generated invoice.

This also factors out the email configs from ICANN reporting into the common 'misc' config, since we'll likely need alert e-mails for future periodic tasks.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=180805972

java/google/registry/billing/BillingEmailUtils.java

@@ -0,0 +1,85 @@
+// Copyright 2017 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.billing;
+
+import com.google.common.collect.ImmutableList;
+import google.registry.config.RegistryConfig.Config;
+import google.registry.util.FormattingLogger;
+import google.registry.util.SendEmailService;
+import javax.inject.Inject;
+import javax.mail.Message;
+import javax.mail.Message.RecipientType;
+import javax.mail.MessagingException;
+import javax.mail.internet.InternetAddress;
+import org.joda.time.YearMonth;
+
+/** Utility functions for sending emails involving monthly invoices. */
+class BillingEmailUtils {
+
+  private final SendEmailService emailService;
+  private final YearMonth yearMonth;
+  private final String alertSenderAddress;
+  private final ImmutableList<String> invoiceEmailRecipients;
+  // TODO(larryruili): Replace this bucket after verifying 2017-12 output.
+  private final String beamBucketUrl;
+
+  @Inject
+  BillingEmailUtils(
+      SendEmailService emailService,
+      YearMonth yearMonth,
+      @Config("alertSenderEmailAddress") String alertSenderAddress,
+      @Config("invoiceEmailRecipients") ImmutableList<String> invoiceEmailRecipients,
+      @Config("apacheBeamBucketUrl") String beamBucketUrl) {
+    this.emailService = emailService;
+    this.yearMonth = yearMonth;
+    this.alertSenderAddress = alertSenderAddress;
+    this.invoiceEmailRecipients = invoiceEmailRecipients;
+    this.beamBucketUrl = beamBucketUrl;
+  }
+
+  private static final FormattingLogger logger = FormattingLogger.getLoggerForCallerClass();
+
+  /**
+   * Sends a link to the generated overall invoice in GCS.
+   *
+   * <p>Note the users receiving the e-mail should have access to the object or bucket, via an
+   * authorization mechanism such as IAM.
+   */
+  void emailInvoiceLink() {
+    // TODO(larryruili): Add read permissions for appropriate buckets.
+    try {
+      String beamBucket = beamBucketUrl.replaceFirst("gs://", "");
+      Message msg = emailService.createMessage();
+      msg.setFrom(new InternetAddress(alertSenderAddress));
+      for (String recipient : invoiceEmailRecipients) {
+        msg.addRecipient(RecipientType.TO, new InternetAddress(recipient));
+      }
+      msg.setSubject(String.format("Domain Registry invoice data %s", yearMonth.toString()));
+      msg.setText(
+          String.format(
+              "Link to invoice on GCS:\nhttps://storage.cloud.google.com/%s/%s",
+              beamBucket,
+              String.format(
+                  "%s%s-%s.csv",
+                  BillingModule.RESULTS_DIRECTORY_PREFIX,
+                  BillingModule.OVERALL_INVOICE_PREFIX,
+                  yearMonth.toString())));
+      emailService.sendMessage(msg);
+    } catch (MessagingException e) {
+      // TODO(larryruili): Replace with retrier with final failure email settings.
+      logger.warning(e, "E-mail service failed due to %s");
+    }
+  }
+}