feat: custom endpoint plugin

common/lib/AllowedAndBlockedHosts.ts

@@ -0,0 +1,33 @@
+/*
+  Copyright Amazon.com, Inc. or its affiliates. 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.
+*/
+
+export class AllowedAndBlockedHosts {
+  private readonly allowedHostIds: Set<string>;
+  private readonly blockedHostIds: Set<string>;
+
+  constructor(allowedHostIds: Set<string>, blockedHostIds: Set<string>) {
+    this.allowedHostIds = allowedHostIds;
+    this.blockedHostIds = blockedHostIds;
+  }
+
+  getAllowedHostIds() {
+    return this.allowedHostIds;
+  }
+
+  getBlockedHostIds() {
+    return this.blockedHostIds;
+  }
+}

common/lib/authentication/iam_authentication_plugin.ts

@@ -15,24 +15,23 @@
 */
 
 import { PluginService } from "../plugin_service";
-import { RdsUtils } from "../utils/rds_utils";
 import { Messages } from "../utils/messages";
 import { logger } from "../../logutils";
 import { AwsWrapperError } from "../utils/errors";
 import { HostInfo } from "../host_info";
 import { AwsCredentialsManager } from "./aws_credentials_manager";
 import { AbstractConnectionPlugin } from "../abstract_connection_plugin";
-import { WrapperProperties } from "../wrapper_property";
+import { WrapperProperties, WrapperProperty } from "../wrapper_property";
 import { IamAuthUtils, TokenInfo } from "../utils/iam_auth_utils";
 import { ClientWrapper } from "../client_wrapper";
+import { RegionUtils } from "../utils/region_utils";
 
 export class IamAuthenticationPlugin extends AbstractConnectionPlugin {
   private static readonly SUBSCRIBED_METHODS = new Set<string>(["connect", "forceConnect"]);
   protected static readonly tokenCache = new Map<string, TokenInfo>();
   private readonly telemetryFactory;
   private readonly fetchTokenCounter;
   private pluginService: PluginService;
-  rdsUtil: RdsUtils = new RdsUtils();
 
   constructor(pluginService: PluginService) {
     super();
@@ -75,7 +74,7 @@ export class IamAuthenticationPlugin extends AbstractConnectionPlugin {
     }
 
     const host = IamAuthUtils.getIamHost(props, hostInfo);
-    const region: string = IamAuthUtils.getRdsRegion(host, this.rdsUtil, props);
+    const region: string = RegionUtils.getRegion(props.get(WrapperProperties.IAM_REGION.name), host);
     const port = IamAuthUtils.getIamPort(props, hostInfo, this.pluginService.getCurrentClient().defaultPort);
     const tokenExpirationSec = WrapperProperties.IAM_TOKEN_EXPIRATION.get(props);
     if (tokenExpirationSec < 0) {

common/lib/connection_plugin_chain_builder.ts

@@ -39,6 +39,7 @@ import { DeveloperConnectionPluginFactory } from "./plugins/dev/developer_connec
 import { ConnectionPluginFactory } from "./plugin_factory";
 import { LimitlessConnectionPluginFactory } from "./plugins/limitless/limitless_connection_plugin_factory";
 import { FastestResponseStrategyPluginFactory } from "./plugins/strategy/fastest_response/fastest_respose_strategy_plugin_factory";
+import { CustomEndpointPluginFactory } from "./plugins/custom_endpoint/custom_endpoint_plugin_factory";
 import { ConfigurationProfile } from "./profile/configuration_profile";
 
 /*
@@ -54,6 +55,7 @@ export class ConnectionPluginChainBuilder {
   static readonly WEIGHT_RELATIVE_TO_PRIOR_PLUGIN = -1;
 
   static readonly PLUGIN_FACTORIES = new Map<string, PluginFactoryInfo>([
+    ["customEndpoint", { factory: CustomEndpointPluginFactory, weight: 380 }],
     ["initialConnection", { factory: AuroraInitialConnectionStrategyFactory, weight: 390 }],
     ["auroraConnectionTracker", { factory: AuroraConnectionTrackerPluginFactory, weight: 400 }],
     ["staleDns", { factory: StaleDnsPluginFactory, weight: 500 }],

common/lib/database_dialect/database_dialect.ts

@@ -21,6 +21,7 @@ import { FailoverRestriction } from "../plugins/failover/failover_restriction";
 import { ErrorHandler } from "../error_handler";
 import { SessionState } from "../session_state";
 import { TransactionIsolationLevel } from "../utils/transaction_isolation_level";
+import { HostRole } from "../host_role";
 
 export enum DatabaseType {
   MYSQL,
@@ -39,6 +40,7 @@ export interface DatabaseDialect {
   getSetSchemaQuery(schema: string): string;
   getDialectUpdateCandidates(): string[];
   getErrorHandler(): ErrorHandler;
+  getHostRole(targetClient: ClientWrapper): Promise<HostRole>;
   isDialect(targetClient: ClientWrapper): Promise<boolean>;
   getHostListProvider(props: Map<string, any>, originalUrl: string, hostListProviderService: HostListProviderService): HostListProvider;
   isClientValid(targetClient: ClientWrapper): Promise<boolean>;

common/lib/host_list_provider/monitoring/monitoring_host_list_provider.ts

@@ -27,6 +27,7 @@ import { Messages } from "../../utils/messages";
 import { WrapperProperties } from "../../wrapper_property";
 import { BlockingHostListProvider } from "../host_list_provider";
 import { logger } from "../../../logutils";
+import { isDialectTopologyAware } from "../../utils/utils";
 
 export class MonitoringRdsHostListProvider extends RdsHostListProvider implements BlockingHostListProvider {
   static readonly CACHE_CLEANUP_NANOS: bigint = BigInt(60_000_000_000); // 1 minute.
@@ -76,7 +77,7 @@ export class MonitoringRdsHostListProvider extends RdsHostListProvider implement
 
   async sqlQueryForTopology(targetClient: ClientWrapper): Promise<HostInfo[]> {
     const dialect: DatabaseDialect = this.hostListProviderService.getDialect();
-    if (!this.isTopologyAwareDatabaseDialect(dialect)) {
+    if (!isDialectTopologyAware(dialect)) {
       throw new TypeError(Messages.get("RdsHostListProvider.incorrectDialect"));
     }
     return await dialect.queryForTopology(targetClient, this).then((res: any) => this.processQueryResults(res));

common/lib/host_list_provider/rds_host_list_provider.ts

@@ -27,8 +27,7 @@ import { WrapperProperties } from "../wrapper_property";
 import { logger } from "../../logutils";
 import { HostAvailability } from "../host_availability/host_availability";
 import { CacheMap } from "../utils/cache_map";
-import { logTopology } from "../utils/utils";
-import { TopologyAwareDatabaseDialect } from "../topology_aware_database_dialect";
+import { isDialectTopologyAware, logTopology } from "../utils/utils";
 import { DatabaseDialect } from "../database_dialect/database_dialect";
 import { ClientWrapper } from "../client_wrapper";
 
@@ -137,7 +136,7 @@ export class RdsHostListProvider implements DynamicHostListProvider {
   }
 
   async getHostRole(client: ClientWrapper, dialect: DatabaseDialect): Promise<HostRole> {
-    if (!this.isTopologyAwareDatabaseDialect(dialect)) {
+    if (!isDialectTopologyAware(dialect)) {
       throw new TypeError(Messages.get("RdsHostListProvider.incorrectDialect"));
     }
 
@@ -150,7 +149,7 @@ export class RdsHostListProvider implements DynamicHostListProvider {
 
   async getWriterId(client: ClientWrapper): Promise<string | null> {
     const dialect = this.hostListProviderService.getDialect();
-    if (!this.isTopologyAwareDatabaseDialect(dialect)) {
+    if (!isDialectTopologyAware(dialect)) {
       throw new TypeError(Messages.get("RdsHostListProvider.incorrectDialect"));
     }
 
@@ -162,7 +161,7 @@ export class RdsHostListProvider implements DynamicHostListProvider {
   }
 
   async identifyConnection(targetClient: ClientWrapper, dialect: DatabaseDialect): Promise<HostInfo | null> {
-    if (!this.isTopologyAwareDatabaseDialect(dialect)) {
+    if (!isDialectTopologyAware(dialect)) {
       throw new TypeError(Messages.get("RdsHostListProvider.incorrectDialect"));
     }
     const instanceName = await dialect.identifyConnection(targetClient);
@@ -276,12 +275,8 @@ export class RdsHostListProvider implements DynamicHostListProvider {
     }
   }
 
-  protected isTopologyAwareDatabaseDialect(arg: any): arg is TopologyAwareDatabaseDialect {
-    return arg;
-  }
-
   async queryForTopology(targetClient: ClientWrapper, dialect: DatabaseDialect): Promise<HostInfo[]> {
-    if (!this.isTopologyAwareDatabaseDialect(dialect)) {
+    if (!isDialectTopologyAware(dialect)) {
       throw new TypeError(Messages.get("RdsHostListProvider.incorrectDialect"));
     }
 

common/lib/host_list_provider_service.ts

@@ -21,6 +21,7 @@ import { DatabaseDialect } from "./database_dialect/database_dialect";
 import { HostInfoBuilder } from "./host_info_builder";
 import { ConnectionUrlParser } from "./utils/connection_url_parser";
 import { TelemetryFactory } from "./utils/telemetry/telemetry_factory";
+import { AllowedAndBlockedHosts } from "./AllowedAndBlockedHosts";
 
 export interface HostListProviderService {
   getHostListProvider(): HostListProvider | null;
@@ -50,4 +51,6 @@ export interface HostListProviderService {
   isClientValid(targetClient: any): Promise<boolean>;
 
   getTelemetryFactory(): TelemetryFactory;
+
+  setAllowedAndBlockedHosts(allowedAndBlockedHosts: AllowedAndBlockedHosts): void;
 }

common/lib/plugin_service.ts

@@ -40,11 +40,13 @@ import { ClientWrapper } from "./client_wrapper";
 import { logger } from "../logutils";
 import { Messages } from "./utils/messages";
 import { DatabaseDialectCodes } from "./database_dialect/database_dialect_codes";
-import { getWriter } from "./utils/utils";
+import { getWriter, logTopology } from "./utils/utils";
 import { TelemetryFactory } from "./utils/telemetry/telemetry_factory";
 import { DriverDialect } from "./driver_dialect/driver_dialect";
+import { AllowedAndBlockedHosts } from "./AllowedAndBlockedHosts";
 
 export class PluginService implements ErrorHandler, HostListProviderService {
+  private static readonly DEFAULT_HOST_AVAILABILITY_CACHE_EXPIRE_NANO = 5 * 60_000_000_000; // 5 minutes
   private readonly _currentClient: AwsClient;
   private _currentHostInfo?: HostInfo;
   private _hostListProvider?: HostListProvider;
@@ -59,6 +61,7 @@ export class PluginService implements ErrorHandler, HostListProviderService {
   protected readonly sessionStateService: SessionStateService;
   protected static readonly hostAvailabilityExpiringCache: CacheMap<string, HostAvailability> = new CacheMap<string, HostAvailability>();
   readonly props: Map<string, any>;
+  private allowedAndBlockedHosts: AllowedAndBlockedHosts | null = null;
 
   constructor(
     container: PluginServiceManagerContainer,
@@ -114,17 +117,29 @@ export class PluginService implements ErrorHandler, HostListProviderService {
       this._currentHostInfo = this._initialConnectionHostInfo;
 
       if (!this._currentHostInfo) {
-        if (this.getHosts().length === 0) {
+        if (this.getAllHosts().length === 0) {
           throw new AwsWrapperError(Messages.get("PluginService.hostListEmpty"));
         }
 
-        const writerHost = getWriter(this.getHosts());
+        const writerHost = getWriter(this.getAllHosts());
+        if (!this.getHosts().some((hostInfo: HostInfo) => hostInfo.host === writerHost?.host)) {
+          throw new AwsWrapperError(
+            Messages.get(
+              "PluginService.currentHostNotAllowed",
+              this._currentHostInfo ? this._currentHostInfo.host : "<null>",
+              logTopology(this.hosts, "[PluginService.currentHostNotAllowed] ")
+            )
+          );
+        }
+
         if (writerHost) {
           this._currentHostInfo = writerHost;
         } else {
           this._currentHostInfo = this.getHosts()[0];
         }
       }
+
+      logger.debug(`Set current host to: ${this._currentHostInfo.host}`);
     }
 
     return this._currentHostInfo;
@@ -286,11 +301,64 @@ export class PluginService implements ErrorHandler, HostListProviderService {
     }
   }
 
-  getHosts(): HostInfo[] {
+  getAllHosts(): HostInfo[] {
     return this.hosts;
   }
 
-  setAvailability(hostAliases: Set<string>, availability: HostAvailability) {}
+  getHosts(): HostInfo[] {
+    const hostPermissions = this.allowedAndBlockedHosts;
+    if (!hostPermissions) {
+      return this.hosts;
+    }
+
+    let hosts = this.hosts;
+    const allowedHostIds = hostPermissions.getAllowedHostIds();
+    const blockedHostIds = hostPermissions.getBlockedHostIds();
+
+    if (allowedHostIds && allowedHostIds.size > 0) {
+      hosts = hosts.filter((host: HostInfo) => allowedHostIds.has(host.hostId));
+    }
+
+    if (blockedHostIds && blockedHostIds.size > 0) {
+      hosts = hosts.filter((host: HostInfo) => !blockedHostIds.has(host.hostId));
+    }
+
+    return hosts;
+  }
+
+  setAvailability(hostAliases: Set<string>, availability: HostAvailability) {
+    if (hostAliases.size === 0) {
+      return;
+    }
+
+    const hostsToChange = [
+      ...new Set(
+        this.getAllHosts().filter(
+          (host: HostInfo) => hostAliases.has(host.asAlias) || [...host.aliases].some((hostAlias: string) => hostAliases.has(hostAlias))
+        )
+      )
+    ];
+
+    if (hostsToChange.length === 0) {
+      logger.debug(Messages.get("PluginService.hostsChangeListEmpty"));
+      return;
+    }
+
+    const changes = new Map<string, Set<HostChangeOptions>>();
+    for (const host of hostsToChange) {
+      const currentAvailability = host.getAvailability();
+      PluginService.hostAvailabilityExpiringCache.put(host.url, availability, PluginService.DEFAULT_HOST_AVAILABILITY_CACHE_EXPIRE_NANO);
+      if (currentAvailability !== availability) {
+        let hostChanges = new Set<HostChangeOptions>();
+        if (availability === HostAvailability.AVAILABLE) {
+          hostChanges = new Set([HostChangeOptions.WENT_UP, HostChangeOptions.HOST_CHANGED]);
+        } else {
+          hostChanges = new Set([HostChangeOptions.WENT_DOWN, HostChangeOptions.HOST_CHANGED]);
+        }
+        changes.set(host.url, hostChanges);
+      }
+    }
+  }
 
   updateConfigWithProperties(props: Map<string, any>) {
     this._currentClient.config = Object.fromEntries(props.entries());
@@ -527,4 +595,8 @@ export class PluginService implements ErrorHandler, HostListProviderService {
   attachNoOpErrorListener(clientWrapper: ClientWrapper | undefined): void {
     this.getDialect().getErrorHandler().attachNoOpErrorListener(clientWrapper);
   }
+
+  setAllowedAndBlockedHosts(allowedAndBlockedHosts: AllowedAndBlockedHosts) {
+    this.allowedAndBlockedHosts = allowedAndBlockedHosts;
+  }
 }

common/lib/plugins/aurora_initial_connection_strategy_plugin.ts

@@ -261,7 +261,7 @@ export class AuroraInitialConnectionStrategyPlugin extends AbstractConnectionPlu
   }
 
   private getWriter(): HostInfo | null {
-    return this.pluginService.getHosts().find((x) => x.role === HostRole.WRITER) ?? null;
+    return this.pluginService.getAllHosts().find((x) => x.role === HostRole.WRITER) ?? null;
   }
 
   private getReader(props: Map<string, any>): HostInfo | undefined {
@@ -278,6 +278,6 @@ export class AuroraInitialConnectionStrategyPlugin extends AbstractConnectionPlu
   }
 
   private hasNoReaders(): boolean {
-    return this.pluginService.getHosts().find((x) => x.role === HostRole.READER) !== undefined;
+    return this.pluginService.getAllHosts().find((x) => x.role === HostRole.READER) !== undefined;
   }
 }

common/lib/plugins/connection_tracker/aurora_connection_tracker_plugin.ts

@@ -99,7 +99,7 @@ export class AuroraConnectionTrackerPlugin extends AbstractConnectionPlugin impl
   }
 
   private async checkWriterChanged(): Promise<void> {
-    const hostInfoAfterFailover = this.getWriter(this.pluginService.getHosts());
+    const hostInfoAfterFailover = this.getWriter(this.pluginService.getAllHosts());
     if (this.currentWriter === null) {
       this.currentWriter = hostInfoAfterFailover;
       this.needUpdateCurrentWriter = false;
@@ -114,7 +114,7 @@ export class AuroraConnectionTrackerPlugin extends AbstractConnectionPlugin impl
 
   private rememberWriter(): void {
     if (this.currentWriter === null || this.needUpdateCurrentWriter) {
-      this.currentWriter = this.getWriter(this.pluginService.getHosts());
+      this.currentWriter = this.getWriter(this.pluginService.getAllHosts());
       this.needUpdateCurrentWriter = false;
     }
   }