xds: add and parse new bootstrap fields for federation (#8608)

Made changes as per "Bootstrap File Changes" section in go/grpc-xds-federation and implemented bootstrap file parsing logic for the change.

xds/src/main/java/io/grpc/xds/Bootstrapper.java

@@ -83,6 +83,38 @@ public abstract class Bootstrapper {
     }
   }
 
+  @AutoValue
+  abstract static class AuthorityInfo {
+
+    /**
+     * A template for the name of the Listener resource to subscribe to for a gRPC client
+     * channel. Used only when the channel is created using an "xds:" URI with this authority
+     * name.
+     *
+     * <p>The token "%s", if present in this string, will be replaced with %-encoded
+     * service authority (i.e., the path part of the target URI used to create the gRPC channel).
+     *
+     * <p>Return value must start with {@code "xdstp://<authority_name>/"}.
+     */
+    abstract String clientListenerResourceNameTemplate();
+
+    /**
+     * Ordered list of xDS servers to contact for this authority.
+     *
+     * <p>If the same server is listed in multiple authorities, the entries will be de-duped (i.e.,
+     * resources for both authorities will be fetched on the same ADS stream).
+     *
+     * <p>If empty, the top-level server list {@link BootstrapInfo#servers()} will be used.
+     */
+    abstract ImmutableList<ServerInfo> xdsServers();
+
+    static AuthorityInfo create(
+        String clientListenerResourceNameTemplate, List<ServerInfo> xdsServers) {
+      return new AutoValue_Bootstrapper_AuthorityInfo(
+          clientListenerResourceNameTemplate, ImmutableList.copyOf(xdsServers));
+    }
+  }
+
   /**
    * Data class containing the results of reading bootstrap.
    */
@@ -99,17 +131,71 @@ public abstract class Bootstrapper {
     @Nullable
     public abstract ImmutableMap<String, CertificateProviderInfo> certProviders();
 
+    /**
+     * A template for the name of the Listener resource to subscribe to for a gRPC server.
+     *
+     * <p>If starts with "xdstp:", will be interpreted as a new-style name, in which case the
+     * authority of the URI will be used to select the relevant configuration in the
+     * "authorities" map. The token "%s", if present in this string, will be replaced with
+     * the IP and port on which the server is listening. If the template starts with "xdstp:",
+     * the replaced string will be %-encoded.
+     *
+     * <p>There is no default; if unset, xDS-based server creation fails.
+     */
     @Nullable
     public abstract String serverListenerResourceNameTemplate();
 
+    /**
+     * A template for the name of the Listener resource to subscribe to for a gRPC client channel.
+     * Used only when the channel is created with an "xds:" URI with no authority.
+     *
+     * <p>If starts with "xdstp:", will be interpreted as a new-style name, in which case the
+     * authority of the URI will be used to select the relevant configuration in the "authorities"
+     * map.
+     *
+     * <p>The token "%s", if present in this string, will be replaced with the service authority
+     * (i.e., the path part of the target URI used to create the gRPC channel). If the template
+     * starts with "xdstp:", the replaced string will be %-encoded.
+     *
+     * <p>Defaults to {@code "%s"}.
+     */
+    abstract String clientDefaultListenerResourceNameTemplate();
+
+    /**
+     * A map of authority name to corresponding configuration.
+     *
+     * <p>This is used in the following cases:
+     *
+     * <ul>
+     * <li>A gRPC client channel is created using an "xds:" URI that includes  an
+     * authority.</li>
+     *
+     * <li>A gRPC client channel is created using an "xds:" URI with no authority,
+     * but the "client_default_listener_resource_name_template" field above turns it into an
+     * "xdstp:" URI.</li>
+     *
+     * <li>A gRPC server is created and the "server_listener_resource_name_template" field is an
+     * "xdstp:" URI.</li>
+     * </ul>
+     *
+     * <p>In any of those cases, it is an error if the specified authority is not present in this
+     * map.
+     *
+     * <p>Defaults to an empty map.
+     */
+    abstract ImmutableMap<String, AuthorityInfo> authorities();
+
     @VisibleForTesting
     static Builder builder() {
-      return new AutoValue_Bootstrapper_BootstrapInfo.Builder();
+      return new AutoValue_Bootstrapper_BootstrapInfo.Builder()
+          .clientDefaultListenerResourceNameTemplate("%s")
+          .authorities(ImmutableMap.<String, AuthorityInfo>of());
     }
 
     @AutoValue.Builder
     @VisibleForTesting
     abstract static class Builder {
+
       abstract Builder servers(List<ServerInfo> servers);
 
       abstract Builder node(Node node);
@@ -119,6 +205,11 @@ public abstract class Bootstrapper {
       abstract Builder serverListenerResourceNameTemplate(
           @Nullable String serverListenerResourceNameTemplate);
 
+      abstract Builder clientDefaultListenerResourceNameTemplate(
+          String clientDefaultListenerResourceNameTemplate);
+
+      abstract Builder authorities(Map<String, AuthorityInfo> authorities);
+
       abstract BootstrapInfo build();
     }
   }

xds/src/main/java/io/grpc/xds/BootstrapperImpl.java

@@ -17,6 +17,8 @@
 package io.grpc.xds;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import io.grpc.ChannelCredentials;
 import io.grpc.InsecureChannelCredentials;
 import io.grpc.Internal;
@@ -33,7 +35,6 @@ import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
-import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -121,41 +122,14 @@ public class BootstrapperImpl extends Bootstrapper {
 
   @Override
   BootstrapInfo bootstrap(Map<String, ?> rawData) throws XdsInitializationException {
-    List<ServerInfo> servers = new ArrayList<>();
+    BootstrapInfo.Builder builder = BootstrapInfo.builder();
+
     List<?> rawServerConfigs = JsonUtil.getList(rawData, "xds_servers");
     if (rawServerConfigs == null) {
       throw new XdsInitializationException("Invalid bootstrap: 'xds_servers' does not exist.");
     }
-    logger.log(XdsLogLevel.INFO, "Configured with {0} xDS servers", rawServerConfigs.size());
+    List<ServerInfo> servers = parseServerInfos(rawServerConfigs, logger);
-    // TODO(chengyuanzhang): require at least one server URI.
+    builder.servers(servers);
-    List<Map<String, ?>> serverConfigList = JsonUtil.checkObjectList(rawServerConfigs);
-    for (Map<String, ?> serverConfig : serverConfigList) {
-      String serverUri = JsonUtil.getString(serverConfig, "server_uri");
-      if (serverUri == null) {
-        throw new XdsInitializationException("Invalid bootstrap: missing 'server_uri'");
-      }
-      logger.log(XdsLogLevel.INFO, "xDS server URI: {0}", serverUri);
-
-      List<?> rawChannelCredsList = JsonUtil.getList(serverConfig, "channel_creds");
-      if (rawChannelCredsList == null || rawChannelCredsList.isEmpty()) {
-        throw new XdsInitializationException(
-            "Invalid bootstrap: server " + serverUri + " 'channel_creds' required");
-      }
-      ChannelCredentials channelCredentials =
-          parseChannelCredentials(JsonUtil.checkObjectList(rawChannelCredsList), serverUri);
-      if (channelCredentials == null) {
-        throw new XdsInitializationException(
-            "Server " + serverUri + ": no supported channel credentials found");
-      }
-
-      boolean useProtocolV3 = false;
-      List<String> serverFeatures = JsonUtil.getListOfStrings(serverConfig, "server_features");
-      if (serverFeatures != null) {
-        logger.log(XdsLogLevel.INFO, "Server features: {0}", serverFeatures);
-        useProtocolV3 = serverFeatures.contains(XDS_V3_SERVER_FEATURE);
-      }
-      servers.add(ServerInfo.create(serverUri, channelCredentials, useProtocolV3));
-    }
 
     Node.Builder nodeBuilder = Node.newBuilder();
     Map<String, ?> rawNode = JsonUtil.getObject(rawData, "node");
@@ -200,29 +174,110 @@ public class BootstrapperImpl extends Bootstrapper {
     nodeBuilder.setUserAgentName(buildVersion.getUserAgent());
     nodeBuilder.setUserAgentVersion(buildVersion.getImplementationVersion());
     nodeBuilder.addClientFeatures(CLIENT_FEATURE_DISABLE_OVERPROVISIONING);
+    builder.node(nodeBuilder.build());
 
     Map<String, ?> certProvidersBlob = JsonUtil.getObject(rawData, "certificate_providers");
-    Map<String, CertificateProviderInfo> certProviders = null;
     if (certProvidersBlob != null) {
-      certProviders = new HashMap<>(certProvidersBlob.size());
+      logger.log(XdsLogLevel.INFO, "Configured with {0} cert providers", certProvidersBlob.size());
+      Map<String, CertificateProviderInfo> certProviders = new HashMap<>(certProvidersBlob.size());
       for (String name : certProvidersBlob.keySet()) {
         Map<String, ?> valueMap = JsonUtil.getObject(certProvidersBlob, name);
         String pluginName =
             checkForNull(JsonUtil.getString(valueMap, "plugin_name"), "plugin_name");
+        logger.log(XdsLogLevel.INFO, "cert provider: {0}, plugin name: {1}", name, pluginName);
         Map<String, ?> config = checkForNull(JsonUtil.getObject(valueMap, "config"), "config");
         CertificateProviderInfo certificateProviderInfo =
             CertificateProviderInfo.create(pluginName, config);
         certProviders.put(name, certificateProviderInfo);
       }
+      builder.certProviders(certProviders);
     }
+
     String grpcServerResourceId =
         JsonUtil.getString(rawData, "server_listener_resource_name_template");
-    return BootstrapInfo.builder()
+    logger.log(
-        .servers(servers)
+        XdsLogLevel.INFO, "server_listener_resource_name_template: {0}", grpcServerResourceId);
-        .node(nodeBuilder.build())
+    builder.serverListenerResourceNameTemplate(grpcServerResourceId);
-        .certProviders(certProviders)
+
-        .serverListenerResourceNameTemplate(grpcServerResourceId)
+    String grpcClientDefaultListener =
-        .build();
+        JsonUtil.getString(rawData, "client_default_listener_resource_name_template");
+    logger.log(
+        XdsLogLevel.INFO, "client_default_listener_resource_name_template: {0}",
+        grpcClientDefaultListener);
+    if (grpcClientDefaultListener != null) {
+      builder.clientDefaultListenerResourceNameTemplate(grpcClientDefaultListener);
+    }
+
+    Map<String, ?> rawAuthoritiesMap =
+        JsonUtil.getObject(rawData, "authorities");
+    ImmutableMap.Builder<String, AuthorityInfo> authorityInfoMapBuilder = ImmutableMap.builder();
+    if (rawAuthoritiesMap != null) {
+      logger.log(
+          XdsLogLevel.INFO, "Configured with {0} xDS server authorities", rawAuthoritiesMap.size());
+      for (String authorityName : rawAuthoritiesMap.keySet()) {
+        logger.log(XdsLogLevel.INFO, "xDS server authority: {0}", authorityName);
+        Map<String, ?> rawAuthority = JsonUtil.getObject(rawAuthoritiesMap, authorityName);
+        String clientListnerTemplate =
+            JsonUtil.getString(rawAuthority, "client_listener_resource_name_template");
+        logger.log(
+            XdsLogLevel.INFO, "client_listener_resource_name_template: {0}", clientListnerTemplate);
+        String prefix = "xdstp://" + authorityName + "/";
+        if (clientListnerTemplate == null) {
+          clientListnerTemplate = prefix + "envoy.config.listener.v3.Listener/%s";
+        } else if (!clientListnerTemplate.startsWith(prefix)) {
+          throw new XdsInitializationException(
+              "client_listener_resource_name_template: '" + clientListnerTemplate
+                  + "' does not start with " + prefix);
+        }
+        List<?> rawAuthorityServers = JsonUtil.getList(rawAuthority, "xds_servers");
+        List<ServerInfo> authorityServers;
+        if (rawAuthorityServers == null || rawAuthorityServers.isEmpty()) {
+          authorityServers = servers;
+        } else {
+          authorityServers = parseServerInfos(rawAuthorityServers, logger);
+        }
+        authorityInfoMapBuilder.put(
+            authorityName, AuthorityInfo.create(clientListnerTemplate, authorityServers));
+      }
+      builder.authorities(authorityInfoMapBuilder.build());
+    }
+
+    return builder.build();
+  }
+
+  private static List<ServerInfo> parseServerInfos(List<?> rawServerConfigs, XdsLogger logger)
+      throws XdsInitializationException {
+    logger.log(XdsLogLevel.INFO, "Configured with {0} xDS servers", rawServerConfigs.size());
+    ImmutableList.Builder<ServerInfo> servers = ImmutableList.builder();
+    List<Map<String, ?>> serverConfigList = JsonUtil.checkObjectList(rawServerConfigs);
+    for (Map<String, ?> serverConfig : serverConfigList) {
+      String serverUri = JsonUtil.getString(serverConfig, "server_uri");
+      if (serverUri == null) {
+        throw new XdsInitializationException("Invalid bootstrap: missing 'server_uri'");
+      }
+      logger.log(XdsLogLevel.INFO, "xDS server URI: {0}", serverUri);
+
+      List<?> rawChannelCredsList = JsonUtil.getList(serverConfig, "channel_creds");
+      if (rawChannelCredsList == null || rawChannelCredsList.isEmpty()) {
+        throw new XdsInitializationException(
+            "Invalid bootstrap: server " + serverUri + " 'channel_creds' required");
+      }
+      ChannelCredentials channelCredentials =
+          parseChannelCredentials(JsonUtil.checkObjectList(rawChannelCredsList), serverUri);
+      if (channelCredentials == null) {
+        throw new XdsInitializationException(
+            "Server " + serverUri + ": no supported channel credentials found");
+      }
+
+      boolean useProtocolV3 = false;
+      List<String> serverFeatures = JsonUtil.getListOfStrings(serverConfig, "server_features");
+      if (serverFeatures != null) {
+        logger.log(XdsLogLevel.INFO, "Server features: {0}", serverFeatures);
+        useProtocolV3 = serverFeatures.contains(XDS_V3_SERVER_FEATURE);
+      }
+      servers.add(ServerInfo.create(serverUri, channelCredentials, useProtocolV3));
+    }
+    return servers.build();
   }
 
   @VisibleForTesting

xds/src/test/java/io/grpc/xds/BootstrapperImplTest.java

@@ -27,6 +27,7 @@ import io.grpc.InsecureChannelCredentials;
 import io.grpc.TlsChannelCredentials;
 import io.grpc.internal.GrpcUtil;
 import io.grpc.internal.GrpcUtil.GrpcBuildVersion;
+import io.grpc.xds.Bootstrapper.AuthorityInfo;
 import io.grpc.xds.Bootstrapper.BootstrapInfo;
 import io.grpc.xds.Bootstrapper.ServerInfo;
 import io.grpc.xds.EnvoyProtoData.Node;
@@ -677,6 +678,101 @@ public class BootstrapperImplTest {
     bootstrapper.bootstrap();
   }
 
+  @Test
+  public void parseClientDefaultListenerResourceNameTemplate() throws Exception {
+    String rawData = "{\n"
+        + "  \"xds_servers\": [\n"
+        + "  ]\n"
+        + "}";
+    bootstrapper.setFileReader(createFileReader(BOOTSTRAP_FILE_PATH, rawData));
+    BootstrapInfo info = bootstrapper.bootstrap();
+    assertThat(info.clientDefaultListenerResourceNameTemplate()).isEqualTo("%s");
+
+    rawData = "{\n"
+        + "  \"client_default_listener_resource_name_template\": \"xdstp://a.com/faketype/%s\",\n"
+        + "  \"xds_servers\": [\n"
+        + "  ]\n"
+        + "}";
+    bootstrapper.setFileReader(createFileReader(BOOTSTRAP_FILE_PATH, rawData));
+    info = bootstrapper.bootstrap();
+    assertThat(info.clientDefaultListenerResourceNameTemplate())
+        .isEqualTo("xdstp://a.com/faketype/%s");
+  }
+
+  @Test
+  public void parseAuthorities() throws Exception {
+    String rawData = "{\n"
+        + "  \"xds_servers\": [\n"
+        + "    {\n"
+        + "      \"server_uri\": \"" + SERVER_URI + "\",\n"
+        + "      \"channel_creds\": [\n"
+        + "        {\"type\": \"insecure\"}\n"
+        + "      ]\n"
+        + "    }\n"
+        + "  ]\n"
+        + "}";
+    bootstrapper.setFileReader(createFileReader(BOOTSTRAP_FILE_PATH, rawData));
+    BootstrapInfo info = bootstrapper.bootstrap();
+    assertThat(info.authorities()).isEmpty();
+
+    rawData = "{\n"
+        + "  \"authorities\": {\n"
+        + "    \"a.com\": {\n"
+        + "      \"client_listener_resource_name_template\": \"xdstp://a.com/v1.Listener/id-%s\"\n"
+        + "    }\n"
+        + "  },\n"
+        + "  \"xds_servers\": [\n"
+        + "    {\n"
+        + "      \"server_uri\": \"" + SERVER_URI + "\",\n"
+        + "      \"channel_creds\": [\n"
+        + "        {\"type\": \"insecure\"}\n"
+        + "      ]\n"
+        + "    }\n"
+        + "  ]\n"
+        + "}";
+    bootstrapper.setFileReader(createFileReader(BOOTSTRAP_FILE_PATH, rawData));
+    info = bootstrapper.bootstrap();
+    assertThat(info.authorities()).hasSize(1);
+    AuthorityInfo authorityInfo = info.authorities().get("a.com");
+    assertThat(authorityInfo.clientListenerResourceNameTemplate())
+        .isEqualTo("xdstp://a.com/v1.Listener/id-%s");
+    // Defaults to top-level servers.
+    assertThat(authorityInfo.xdsServers()).hasSize(1);
+    assertThat(authorityInfo.xdsServers().get(0).target()).isEqualTo(SERVER_URI);
+
+    rawData = "{\n"
+        + "  \"authorities\": {\n"
+        + "    \"a.com\": {\n"
+        + "      \"xds_servers\": [\n"
+        + "        {\n"
+        + "          \"server_uri\": \"td2.googleapis.com:443\",\n"
+        + "          \"channel_creds\": [\n"
+        + "            {\"type\": \"insecure\"}\n"
+        + "          ]\n"
+        + "        }\n"
+        + "      ]\n"
+        + "    }\n"
+        + "  },\n"
+        + "  \"xds_servers\": [\n"
+        + "    {\n"
+        + "      \"server_uri\": \"" + SERVER_URI + "\",\n"
+        + "      \"channel_creds\": [\n"
+        + "        {\"type\": \"insecure\"}\n"
+        + "      ]\n"
+        + "    }\n"
+        + "  ]\n"
+        + "}";
+    bootstrapper.setFileReader(createFileReader(BOOTSTRAP_FILE_PATH, rawData));
+    info = bootstrapper.bootstrap();
+    assertThat(info.authorities()).hasSize(1);
+    authorityInfo = info.authorities().get("a.com");
+    // Defaults to "xdstp://<authority_name>>/envoy.config.listener.v3.Listener/%s"
+    assertThat(authorityInfo.clientListenerResourceNameTemplate())
+        .isEqualTo("xdstp://a.com/envoy.config.listener.v3.Listener/%s");
+    assertThat(authorityInfo.xdsServers()).hasSize(1);
+    assertThat(authorityInfo.xdsServers().get(0).target()).isEqualTo("td2.googleapis.com:443");
+  }
+
   private static BootstrapperImpl.FileReader createFileReader(
       final String expectedPath, final String rawData) {
     return new BootstrapperImpl.FileReader() {