Introduce PowerDnsWriter for zone synchronization to PowerDNS

core/src/main/java/google/registry/config/RegistryConfig.java

@@ -72,8 +72,8 @@
 public final class RegistryConfig {
 
   public static final String CANARY_HEADER = "canary";
-  private static final String ENVIRONMENT_CONFIG_FORMAT = "files/nomulus-config-%s.yaml";
-  private static final String YAML_CONFIG_PROD =
+  private static final String YAML_CONFIG_ENV_TEMPLATE = "files/nomulus-config-%s.yaml";
+  private static final String YAML_CONFIG_DEFAULT =
       readResourceUtf8(RegistryConfig.class, "files/default-config.yaml");
 
   /** Dagger qualifier for configuration settings. */
@@ -85,19 +85,18 @@ public final class RegistryConfig {
   }
 
   /**
-   * Loads the {@link RegistryConfigSettings} POJO from the YAML configuration files.
+   * Loads a generic typed POJO from the YAML configuration files.
    *
-   * <p>The {@code default-config.yaml} file in this directory is loaded first, and a fatal error is
-   * thrown if it cannot be found or if there is an error parsing it. Separately, the
-   * environment-specific config file named {@code nomulus-config-ENVIRONMENT.yaml} is also loaded
-   * and those values merged into the POJO.
+   * <p>The {@code defaultYaml} file is loaded first, and a fatal error is thrown if it cannot be
+   * found or if there is an error parsing it. Separately, the environment-specific config file
+   * template {@code customYamlTemplate} is also loaded and those values merged into the POJO.
    */
-  static RegistryConfigSettings getConfigSettings() {
+  public static <T> T getEnvironmentConfigSettings(
+      String defaultYaml, String customYamlTemplate, Class<T> clazz) {
     String configFilePath =
-        String.format(
-            ENVIRONMENT_CONFIG_FORMAT, Ascii.toLowerCase(RegistryEnvironment.get().name()));
+        String.format(customYamlTemplate, Ascii.toLowerCase(RegistryEnvironment.get().name()));
     String customYaml = readResourceUtf8(RegistryConfig.class, configFilePath);
-    return YamlUtils.getConfigSettings(YAML_CONFIG_PROD, customYaml, RegistryConfigSettings.class);
+    return YamlUtils.getConfigSettings(defaultYaml, customYaml, clazz);
   }
 
   /** Dagger module for providing configuration settings. */
@@ -1723,7 +1722,10 @@ public static ImmutableSet<String> getNoPollMessageOnDeletionRegistrarIds() {
    */
   @VisibleForTesting
   public static final Supplier<RegistryConfigSettings> CONFIG_SETTINGS =
-      memoize(RegistryConfig::getConfigSettings);
+      memoize(
+          () ->
+              RegistryConfig.getEnvironmentConfigSettings(
+                  YAML_CONFIG_DEFAULT, YAML_CONFIG_ENV_TEMPLATE, RegistryConfigSettings.class));
 
   private static InternetAddress parseEmailAddress(String email) {
     try {

core/src/main/java/google/registry/config/files/power-dns/default.yaml

@@ -0,0 +1,10 @@
+# Default configuration for PowerDNS
+powerDns:
+  baseUrl: http://localhost:8081/api/v1
+  apiKey: example-api-key
+  dnssecEnabled: false
+  tsigEnabled: true
+  rootNameServers:
+  - ns1.example.com.
+  - ns2.example.com.
+  soaName: nstld.example.com.

core/src/main/java/google/registry/config/files/power-dns/env-alpha.yaml

@@ -0,0 +1 @@
+# Add environment-specific configuration here.

core/src/main/java/google/registry/config/files/power-dns/env-crash.yaml

@@ -0,0 +1 @@
+# Add environment-specific configuration here.

core/src/main/java/google/registry/config/files/power-dns/env-local.yaml

@@ -0,0 +1 @@
+# Add environment-specific configuration here.

core/src/main/java/google/registry/config/files/power-dns/env-production.yaml

@@ -0,0 +1 @@
+# Add environment-specific configuration here.

core/src/main/java/google/registry/config/files/power-dns/env-qa.yaml

@@ -0,0 +1 @@
+# Add environment-specific configuration here.

core/src/main/java/google/registry/config/files/power-dns/env-sandbox.yaml

@@ -0,0 +1 @@
+# Add environment-specific configuration here.

core/src/main/java/google/registry/config/files/power-dns/env-unittest.yaml

@@ -0,0 +1,10 @@
+# Add environment-specific configuration here.
+powerDns:
+  baseUrl: http://unittest:8081/api/v1
+  apiKey: unittest-api-key
+  dnssecEnabled: true
+  tsigEnabled: true
+  rootNameServers:
+  - ns1.unittest.com.
+  - ns2.unittest.com.
+  soaName: nstld.unittest.com.

core/src/main/java/google/registry/dns/writer/dnsupdate/DnsUpdateWriter.java

@@ -90,9 +90,9 @@ public class DnsUpdateWriter extends BaseDnsWriter {
   private final Duration dnsDefaultNsTtl;
   private final Duration dnsDefaultDsTtl;
   private final DnsMessageTransport transport;
-  private final Clock clock;
-  private final Update update;
-  private final String zoneName;
+  protected final Clock clock;
+  protected final Update update;
+  protected final String zoneName;
 
   /**
    * Class constructor.

core/src/main/java/google/registry/dns/writer/powerdns/PowerDnsConfig.java

@@ -0,0 +1,113 @@
+// Copyright 2025 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.dns.writer.powerdns;
+
+import static com.google.common.base.Suppliers.memoize;
+import static google.registry.util.ResourceUtils.readResourceUtf8;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableList;
+import dagger.Module;
+import dagger.Provides;
+import google.registry.config.RegistryConfig;
+import google.registry.config.RegistryConfig.Config;
+import jakarta.inject.Singleton;
+import java.util.function.Supplier;
+
+/**
+ * Configuration manager for PowerDNS settings.
+ *
+ * <p>This class is responsible for loading the PowerDNS configuration from the YAML files, found in
+ * the {@code files/power-dns} directory.
+ */
+public final class PowerDnsConfig {
+
+  // expected config file locations for PowerDNS
+  private static final String YAML_CONFIG_ENV_TEMPLATE = "files/power-dns/env-%s.yaml";
+  private static final String YAML_CONFIG_DEFAULT =
+      readResourceUtf8(RegistryConfig.class, "files/power-dns/default.yaml");
+
+  /** Dagger module that provides DNS configuration settings. */
+  @Module
+  public static final class PowerDnsConfigModule {
+
+    /** Parsed PowerDNS configuration settings. */
+    @Singleton
+    @Provides
+    static PowerDnsConfigSettings providePowerDnsConfigSettings() {
+      return CONFIG_SETTINGS.get();
+    }
+
+    /** Base URL of the PowerDNS server. */
+    @Provides
+    @Config("powerDnsBaseUrl")
+    public static String providePowerDnsBaseUrl(PowerDnsConfigSettings config) {
+      return config.powerDns.baseUrl;
+    }
+
+    /** API key for the PowerDNS server. */
+    @Provides
+    @Config("powerDnsApiKey")
+    public static String providePowerDnsApiKey(PowerDnsConfigSettings config) {
+      return config.powerDns.apiKey;
+    }
+
+    /** Whether DNSSEC is enabled for the PowerDNS server. */
+    @Provides
+    @Config("powerDnsDnssecEnabled")
+    public static Boolean providePowerDnsDnssecEnabled(PowerDnsConfigSettings config) {
+      return config.powerDns.dnssecEnabled;
+    }
+
+    /** Whether TSIG is enabled for the PowerDNS server. */
+    @Provides
+    @Config("powerDnsTsigEnabled")
+    public static Boolean providePowerDnsTsigEnabled(PowerDnsConfigSettings config) {
+      return config.powerDns.tsigEnabled;
+    }
+
+    /** Default SOA MNAME for the TLD zone. */
+    @Provides
+    @Config("powerDnsRootNameServers")
+    public static ImmutableList<String> providePowerDnsRootNameServers(
+        PowerDnsConfigSettings config) {
+      return ImmutableList.copyOf(config.powerDns.rootNameServers);
+    }
+
+    /** Default SOA RNAME for the TLD zone. */
+    @Provides
+    @Config("powerDnsSoaName")
+    public static String providePowerDnsSoaName(PowerDnsConfigSettings config) {
+      return config.powerDns.soaName;
+    }
+
+    private PowerDnsConfigModule() {}
+  }
+
+  /**
+   * Memoizes loading of the {@link PowerDnsConfigSettings} POJO.
+   *
+   * <p>Memoizing without cache expiration is used because the app must be re-deployed in order to
+   * change the contents of the YAML config files.
+   */
+  @VisibleForTesting
+  public static final Supplier<PowerDnsConfigSettings> CONFIG_SETTINGS =
+      memoize(
+          () ->
+              RegistryConfig.getEnvironmentConfigSettings(
+                  YAML_CONFIG_DEFAULT, YAML_CONFIG_ENV_TEMPLATE, PowerDnsConfigSettings.class));
+
+  private PowerDnsConfig() {}
+}

core/src/main/java/google/registry/dns/writer/powerdns/PowerDnsConfigSettings.java

@@ -0,0 +1,32 @@
+// Copyright 2025 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.dns.writer.powerdns;
+
+import java.util.List;
+
+/** The POJO that PowerDNS YAML config files are deserialized into. */
+public class PowerDnsConfigSettings {
+
+  public PowerDns powerDns;
+
+  public static class PowerDns {
+    public String baseUrl;
+    public String apiKey;
+    public Boolean dnssecEnabled;
+    public Boolean tsigEnabled;
+    public List<String> rootNameServers;
+    public String soaName;
+  }
+}