feat(rds): unify ParameterGroup and ClusterParameterGroup (aws#8959)

The classes ParameterGroup and ClusterParameterGroup were basically identical;
they only differed in the L1 that was created in their scope.
Unify the classes by adding a bind()-like protocol between ParameterGroup and cluster/instance,
which allows us to only have a single class instead of 2.

Fixes aws#8932

BREAKING CHANGE: the class ClusterParameterGroup has been removed -
  use ParameterGroup instead

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk/aws-rds/lib/cluster-engine.ts

@@ -1,9 +1,9 @@
 import * as iam from '@aws-cdk/aws-iam';
 import * as secretsmanager from '@aws-cdk/aws-secretsmanager';
 import * as core from '@aws-cdk/core';
-import { ClusterParameterGroup, IParameterGroup, ParameterGroup } from './parameter-group';
-import { ParameterGroupFamilyMapping } from './private/parameter-group-family-mapping';
-import { compare } from './private/version';
+import { IEngine } from './engine';
+import { IParameterGroup, ParameterGroup } from './parameter-group';
+import { calculateParameterGroupFamily, ParameterGroupFamilyMapping } from './private/parameter-group-family-mapping';
 
 /**
  * The extra options passed to the {@link IClusterEngine.bindToCluster} method.
@@ -54,25 +54,7 @@ export interface ClusterEngineConfig {
 /**
  * The interface representing a database cluster (as opposed to instance) engine.
  */
-export interface IClusterEngine {
-  /** The type of the engine, for example "aurora-mysql". */
-  readonly engineType: string;
-
-  /**
-   * The exact version of a given engine.
-   *
-   * @default - default version for the given engine type
-   */
-  readonly engineVersion?: string;
-
-  /**
-   * The family to use for ParameterGroups using this engine.
-   * This is usually equal to "<engineType><engineMajorVersion>",
-   * but can sometimes be a variation of that.
-   * You can pass this property when creating new ClusterParameterGroup.
-   */
-  readonly parameterGroupFamily: string;
-
+export interface IClusterEngine extends IEngine {
   /** The application used by this engine to perform rotation for a single-user scenario. */
   readonly singleUserRotationApplication: secretsmanager.SecretRotationApplication;
 
@@ -101,17 +83,19 @@ abstract class ClusterEngineBase implements IClusterEngine {
   public readonly singleUserRotationApplication: secretsmanager.SecretRotationApplication;
   public readonly multiUserRotationApplication: secretsmanager.SecretRotationApplication;
 
-  private readonly parameterGroupFamilies?: ParameterGroupFamilyMapping[];
   private readonly defaultPort?: number;
 
   constructor(props: ClusterEngineBaseProps) {
     this.engineType = props.engineType;
     this.singleUserRotationApplication = props.singleUserRotationApplication;
     this.multiUserRotationApplication = props.multiUserRotationApplication;
-    this.parameterGroupFamilies = props.parameterGroupFamilies;
     this.defaultPort = props.defaultPort;
     this.engineVersion = props.engineVersion;
-    this.parameterGroupFamily = this.establishParameterGroupFamily();
+    const parameterGroupFamily = calculateParameterGroupFamily(props.parameterGroupFamilies, props.engineVersion);
+    if (parameterGroupFamily === undefined) {
+      throw new Error(`No parameter group family found for database engine ${this.engineType} with version ${this.engineVersion}.`);
+    }
+    this.parameterGroupFamily = parameterGroupFamily;
   }
 
   public bindToCluster(scope: core.Construct, options: ClusterEngineBindOptions): ClusterEngineConfig {
@@ -128,46 +112,14 @@ abstract class ClusterEngineBase implements IClusterEngine {
    * if one wasn't provided by the customer explicitly.
    */
   protected abstract defaultParameterGroup(scope: core.Construct): IParameterGroup | undefined;
-
-  private establishParameterGroupFamily(): string {
-    const ret = this.calculateParameterGroupFamily();
-    if (ret === undefined) {
-      throw new Error(`No parameter group family found for database engine ${this.engineType} with version ${this.engineVersion}.`);
-    }
-    return ret;
-  }
-
-  /**
-   * Get the latest parameter group family for this engine. Latest is determined using semver on the engine major version.
-   * When `engineVersion` is specified, return the parameter group family corresponding to that engine version.
-   * Return undefined if no parameter group family is defined for this engine or for the requested `engineVersion`.
-   */
-  private calculateParameterGroupFamily(): string | undefined {
-    if (this.parameterGroupFamilies === undefined) {
-      return undefined;
-    }
-    const engineVersion = this.engineVersion;
-    if (engineVersion !== undefined) {
-      const family = this.parameterGroupFamilies.find(x => engineVersion.startsWith(x.engineMajorVersion));
-      if (family) {
-        return family.parameterGroupFamily;
-      }
-    } else if (this.parameterGroupFamilies.length > 0) {
-      const sorted = this.parameterGroupFamilies.slice().sort((a, b) => {
-        return compare(a.engineMajorVersion, b.engineMajorVersion);
-      }).reverse();
-      return sorted[0].parameterGroupFamily;
-    }
-    return undefined;
-  }
 }
 
 abstract class MySqlClusterEngineBase extends ClusterEngineBase {
   public bindToCluster(scope: core.Construct, options: ClusterEngineBindOptions): ClusterEngineConfig {
     const config = super.bindToCluster(scope, options);
     const parameterGroup = options.parameterGroup ?? (options.s3ImportRole || options.s3ExportRole
-      ? new ClusterParameterGroup(scope, 'ClusterParameterGroup', {
-        family: this.parameterGroupFamily,
+      ? new ParameterGroup(scope, 'ClusterParameterGroup', {
+        engine: this,
       })
       : config.parameterGroup);
     if (options.s3ImportRole) {

packages/@aws-cdk/aws-rds/lib/cluster.ts

@@ -415,6 +415,7 @@ export class DatabaseCluster extends DatabaseClusterBase {
       parameterGroup: props.parameterGroup,
     });
     const clusterParameterGroup = props.parameterGroup ?? clusterEngineBindConfig.parameterGroup;
+    const clusterParameterGroupConfig = clusterParameterGroup?.bindToCluster({});
 
     const cluster = new CfnDBCluster(this, 'Resource', {
       // Basic
@@ -424,7 +425,7 @@ export class DatabaseCluster extends DatabaseClusterBase {
       dbSubnetGroupName: subnetGroup.ref,
       vpcSecurityGroupIds: securityGroups.map(sg => sg.securityGroupId),
       port: props.port ?? clusterEngineBindConfig.port,
-      dbClusterParameterGroupName: clusterParameterGroup && clusterParameterGroup.parameterGroupName,
+      dbClusterParameterGroupName: clusterParameterGroupConfig?.parameterGroupName,
       associatedRoles: clusterAssociatedRoles.length > 0 ? clusterAssociatedRoles : undefined,
       // Admin
       masterUsername: secret ? secret.secretValueFromJson('username').toString() : props.masterUser.username,
@@ -483,6 +484,7 @@ export class DatabaseCluster extends DatabaseClusterBase {
     }
 
     const instanceType = props.instanceProps.instanceType ?? ec2.InstanceType.of(ec2.InstanceClass.T3, ec2.InstanceSize.MEDIUM);
+    const instanceParameterGroupConfig = props.instanceProps.parameterGroup?.bindToInstance({});
     for (let i = 0; i < instanceCount; i++) {
       const instanceIndex = i + 1;
 
@@ -503,7 +505,7 @@ export class DatabaseCluster extends DatabaseClusterBase {
         publiclyAccessible,
         // This is already set on the Cluster. Unclear to me whether it should be repeated or not. Better yes.
         dbSubnetGroupName: subnetGroup.ref,
-        dbParameterGroupName: props.instanceProps.parameterGroup && props.instanceProps.parameterGroup.parameterGroupName,
+        dbParameterGroupName: instanceParameterGroupConfig?.parameterGroupName,
         monitoringInterval: props.monitoringInterval && props.monitoringInterval.toSeconds(),
         monitoringRoleArn: monitoringRole && monitoringRole.roleArn,
       });

packages/@aws-cdk/aws-rds/lib/engine.ts

@@ -0,0 +1,26 @@
+/**
+ * A common interface for database engines.
+ * Don't implement this interface directly,
+ * instead implement one of the known sub-interfaces,
+ * like IClusterEngine and IInstanceEngine.
+ */
+export interface IEngine {
+  /** The type of the engine, for example "mysql". */
+  readonly engineType: string;
+
+  /**
+   * The exact version of the engine that is used,
+   * for example "5.1.42".
+   *
+   * @default - use the default version for this engine type
+   */
+  readonly engineVersion?: string;
+
+  /**
+   * The family to use for ParameterGroups using this engine.
+   * This is usually equal to "<engineType><engineMajorVersion>",
+   * but can sometimes be a variation of that.
+   * You can pass this property when creating new ParameterGroup.
+   */
+  readonly parameterGroupFamily: string;
+}

packages/@aws-cdk/aws-rds/lib/index.ts

@@ -1,3 +1,4 @@
+export * from './engine';
 export * from './cluster';
 export * from './cluster-ref';
 export * from './cluster-engine';

packages/@aws-cdk/aws-rds/lib/instance-engine.ts

@@ -1,7 +1,8 @@
 import * as ec2 from '@aws-cdk/aws-ec2';
 import * as secretsmanager from '@aws-cdk/aws-secretsmanager';
 import * as core from '@aws-cdk/core';
-import { ParameterGroupFamilyMapping } from './private/parameter-group-family-mapping';
+import { IEngine } from './engine';
+import { calculateParameterGroupFamily, ParameterGroupFamilyMapping } from './private/parameter-group-family-mapping';
 
 /**
  * The options passed to {@link IInstanceEngine.bind}.
@@ -26,18 +27,7 @@ export interface InstanceEngineConfig {
 /**
  * Interface representing a database instance (as opposed to cluster) engine.
  */
-export interface IInstanceEngine {
-  /** The type of the engine, for example "mysql". */
-  readonly engineType: string;
-
-  /**
-   * The exact version of the engine that is used,
-   * for example "5.1.42".
-   *
-   * @default - use the default version for this engine type
-   */
-  readonly engineVersion?: string;
-
+export interface IInstanceEngine extends IEngine {
   /** The application used by this engine to perform rotation for a single-user scenario. */
   readonly singleUserRotationApplication: secretsmanager.SecretRotationApplication;
 
@@ -61,6 +51,7 @@ interface InstanceEngineBaseProps {
 abstract class InstanceEngineBase implements IInstanceEngine {
   public readonly engineType: string;
   public readonly engineVersion?: string;
+  public readonly parameterGroupFamily: string;
   public readonly singleUserRotationApplication: secretsmanager.SecretRotationApplication;
   public readonly multiUserRotationApplication: secretsmanager.SecretRotationApplication;
 
@@ -69,6 +60,11 @@ abstract class InstanceEngineBase implements IInstanceEngine {
     this.singleUserRotationApplication = props.singleUserRotationApplication;
     this.multiUserRotationApplication = props.multiUserRotationApplication;
     this.engineVersion = props.version;
+    const parameterGroupFamily = calculateParameterGroupFamily(props.parameterGroupFamilies, props.version);
+    if (parameterGroupFamily === undefined) {
+      throw new Error(`No parameter group family found for database engine ${this.engineType} with version ${this.engineVersion}.`);
+    }
+    this.parameterGroupFamily = parameterGroupFamily;
   }
 
   public bindToInstance(_scope: core.Construct, options: InstanceEngineBindOptions): InstanceEngineConfig {
@@ -231,6 +227,7 @@ class OracleSe2InstanceEngine extends OracleInstanceEngine {
     super({
       engineType: 'oracle-se2',
       parameterGroupFamilies: [
+        { engineMajorVersion: '11.2', parameterGroupFamily: 'oracle-se2-11.2' },
         { engineMajorVersion: '12.1', parameterGroupFamily: 'oracle-se2-12.1' },
         { engineMajorVersion: '12.2', parameterGroupFamily: 'oracle-se2-12.2' },
         { engineMajorVersion: '18',   parameterGroupFamily: 'oracle-se2-18'   },

packages/@aws-cdk/aws-rds/lib/instance.ts

@@ -678,12 +678,13 @@ abstract class DatabaseInstanceSource extends DatabaseInstanceNew implements IDa
     props.engine.bindToInstance(this, props);
     this.instanceType = props.instanceType ?? ec2.InstanceType.of(ec2.InstanceClass.M5, ec2.InstanceSize.LARGE);
 
+    const instanceParameterGroupConfig = props.parameterGroup?.bindToInstance({});
     this.sourceCfnProps = {
       ...this.newCfnProps,
       allocatedStorage: props.allocatedStorage ? props.allocatedStorage.toString() : '100',
       allowMajorVersionUpgrade: props.allowMajorVersionUpgrade,
       dbName: props.databaseName,
-      dbParameterGroupName: props.parameterGroup && props.parameterGroup.parameterGroupName,
+      dbParameterGroupName: instanceParameterGroupConfig?.parameterGroupName,
       engine: props.engine.engineType,
       engineVersion: props.engine.engineVersion,
       licenseModel: props.licenseModel,