fix(rds): Add engine to IDatabaseInstance, IClusterInstance

packages/@aws-cdk/aws-rds/README.md

@@ -112,6 +112,20 @@ const instance = new rds.DatabaseInstance(this, 'Instance', {
 });
 ```
 
+To import an already existing instance:
+
+```ts
+rds.DatabaseInstance.fromDatabaseInstanceAttributes(stack, 'Database', {
+  engine: rds.DatabaseInstanceEngine.mysql({ version: rds.MysqlEngineVersion.VER_5_7_30 }),
+  instanceEndpointAddress: 'address',
+  instanceIdentifier: 'identifier',
+  port: 3306,
+  securityGroups: [ec2.SecurityGroup.fromSecurityGroupId(stack, 'SG', 'sg-123456789', {
+    allowAllOutbound: false,
+  })],
+});
+```
+
 Use `DatabaseInstanceFromSnapshot` and `DatabaseInstanceReadReplica` to create an instance from snapshot or
 a source database respectively:
 

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

@@ -1,13 +1,19 @@
 import * as ec2 from '@aws-cdk/aws-ec2';
 import * as secretsmanager from '@aws-cdk/aws-secretsmanager';
 import { IResource } from '@aws-cdk/core';
+import { IClusterEngine } from './cluster-engine';
 import { Endpoint } from './endpoint';
 import { DatabaseProxy, DatabaseProxyOptions } from './proxy';
 
 /**
  * Create a clustered database with a given number of instances.
  */
 export interface IDatabaseCluster extends IResource, ec2.IConnectable, secretsmanager.ISecretAttachmentTarget {
+  /**
+   * The database engine
+   */
+  readonly engine: IClusterEngine;
+
   /**
    * Identifier of the cluster
    */
@@ -45,6 +51,11 @@ export interface IDatabaseCluster extends IResource, ec2.IConnectable, secretsma
  * Properties that describe an existing cluster instance
  */
 export interface DatabaseClusterAttributes {
+  /**
+   * The database engine
+   */
+  readonly engine: IClusterEngine;
+
   /**
    * The database port
    */

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

@@ -205,6 +205,10 @@ export interface DatabaseClusterProps {
  * A new or imported clustered database.
  */
 abstract class DatabaseClusterBase extends Resource implements IDatabaseCluster {
+  /**
+   * The database engine
+   */
+  public abstract readonly engine: IClusterEngine;
   /**
    * Identifier of the cluster
    */
@@ -271,6 +275,7 @@ export class DatabaseCluster extends DatabaseClusterBase {
         securityGroups: attrs.securityGroups,
         defaultPort: this.defaultPort,
       });
+      public readonly engine = attrs.engine;
       public readonly clusterIdentifier = attrs.clusterIdentifier;
       public readonly instanceIdentifiers: string[] = [];
       public readonly clusterEndpoint = new Endpoint(attrs.clusterEndpointAddress, attrs.port);
@@ -281,6 +286,11 @@ export class DatabaseCluster extends DatabaseClusterBase {
     return new Import(scope, id);
   }
 
+  /**
+   * The database engine
+   */
+  public readonly engine: IClusterEngine;
+
   /**
    * Identifier of the cluster
    */
@@ -528,6 +538,7 @@ export class DatabaseCluster extends DatabaseClusterBase {
 
     const defaultPort = ec2.Port.tcp(this.clusterEndpoint.port);
     this.connections = new ec2.Connections({ securityGroups, defaultPort });
+    this.engine = props.engine;
   }
 
   /**

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

@@ -19,6 +19,11 @@ import { CfnDBInstance, CfnDBInstanceProps, CfnDBSubnetGroup } from './rds.gener
  * A database instance
  */
 export interface IDatabaseInstance extends IResource, ec2.IConnectable, secretsmanager.ISecretAttachmentTarget {
+  /**
+   * The database engine.
+   */
+  readonly engine: IInstanceEngine;
+
   /**
    * The instance identifier.
    */
@@ -64,6 +69,11 @@ export interface IDatabaseInstance extends IResource, ec2.IConnectable, secretsm
  * Properties that describe an existing instance
  */
 export interface DatabaseInstanceAttributes {
+  /**
+   * The database engine.
+   */
+  readonly engine: IInstanceEngine;
+
   /**
    * The instance identifier.
    */
@@ -99,6 +109,7 @@ export abstract class DatabaseInstanceBase extends Resource implements IDatabase
         securityGroups: attrs.securityGroups,
         defaultPort: this.defaultPort,
       });
+      public readonly engine = attrs.engine;
       public readonly instanceIdentifier = attrs.instanceIdentifier;
       public readonly dbInstanceEndpointAddress = attrs.instanceEndpointAddress;
       public readonly dbInstanceEndpointPort = attrs.port.toString();
@@ -108,6 +119,7 @@ export abstract class DatabaseInstanceBase extends Resource implements IDatabase
     return new Import(scope, id);
   }
 
+  public abstract readonly engine: IInstanceEngine;
   public abstract readonly instanceIdentifier: string;
   public abstract readonly dbInstanceEndpointAddress: string;
   public abstract readonly dbInstanceEndpointPort: string;
@@ -776,6 +788,7 @@ export interface DatabaseInstanceProps extends DatabaseInstanceSourceProps {
  * @resource AWS::RDS::DBInstance
  */
 export class DatabaseInstance extends DatabaseInstanceSource implements IDatabaseInstance {
+  public readonly engine: IInstanceEngine;
   public readonly instanceIdentifier: string;
   public readonly dbInstanceEndpointAddress: string;
   public readonly dbInstanceEndpointPort: string;
@@ -804,6 +817,7 @@ export class DatabaseInstance extends DatabaseInstanceSource implements IDatabas
       storageEncrypted: props.storageEncryptionKey ? true : props.storageEncrypted,
     });
 
+    this.engine = props.engine;
     this.instanceIdentifier = instance.ref;
     this.dbInstanceEndpointAddress = instance.attrEndpointAddress;
     this.dbInstanceEndpointPort = instance.attrEndpointPort;
@@ -862,6 +876,7 @@ export interface DatabaseInstanceFromSnapshotProps extends DatabaseInstanceSourc
  * @resource AWS::RDS::DBInstance
  */
 export class DatabaseInstanceFromSnapshot extends DatabaseInstanceSource implements IDatabaseInstance {
+  public readonly engine: IInstanceEngine;
   public readonly instanceIdentifier: string;
   public readonly dbInstanceEndpointAddress: string;
   public readonly dbInstanceEndpointPort: string;
@@ -900,6 +915,7 @@ export class DatabaseInstanceFromSnapshot extends DatabaseInstanceSource impleme
         : props.masterUserPassword && props.masterUserPassword.toString(),
     });
 
+    this.engine = props.engine;
     this.instanceIdentifier = instance.ref;
     this.dbInstanceEndpointAddress = instance.attrEndpointAddress;
     this.dbInstanceEndpointPort = instance.attrEndpointPort;
@@ -957,6 +973,7 @@ export interface DatabaseInstanceReadReplicaProps extends DatabaseInstanceNewPro
  * @resource AWS::RDS::DBInstance
  */
 export class DatabaseInstanceReadReplica extends DatabaseInstanceNew implements IDatabaseInstance {
+  public readonly engine: IInstanceEngine;
   public readonly instanceIdentifier: string;
   public readonly dbInstanceEndpointAddress: string;
   public readonly dbInstanceEndpointPort: string;
@@ -974,6 +991,7 @@ export class DatabaseInstanceReadReplica extends DatabaseInstanceNew implements
       storageEncrypted: props.storageEncryptionKey ? true : props.storageEncrypted,
     });
 
+    this.engine = props.sourceDatabaseInstance.engine;
     this.instanceType = props.instanceType;
     this.instanceIdentifier = instance.ref;
     this.dbInstanceEndpointAddress = instance.attrEndpointAddress;

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

@@ -4,7 +4,7 @@ import * as secretsmanager from '@aws-cdk/aws-secretsmanager';
 import * as cdk from '@aws-cdk/core';
 import { IDatabaseCluster } from './cluster-ref';
 import { IDatabaseInstance } from './instance';
-import { CfnDBCluster, CfnDBInstance, CfnDBProxy, CfnDBProxyTargetGroup } from './rds.generated';
+import { CfnDBProxy, CfnDBProxyTargetGroup } from './rds.generated';
 
 /**
  * SessionPinningFilter
@@ -65,17 +65,17 @@ export class ProxyTarget {
    * Bind this target to the specified database proxy.
    */
   public bind(_: DatabaseProxy): ProxyTargetConfig {
-    let engine: string | undefined;
+    let engineType: string | undefined;
     if (this.dbCluster && this.dbInstance) {
       throw new Error('Proxy cannot target both database cluster and database instance.');
     } else if (this.dbCluster) {
-      engine = (this.dbCluster.node.defaultChild as CfnDBCluster).engine;
+      engineType = this.dbCluster.engine.engineType;
     } else if (this.dbInstance) {
-      engine = (this.dbInstance.node.defaultChild as CfnDBInstance).engine;
+      engineType = this.dbInstance.engine.engineType;
     }
 
     let engineFamily;
-    switch (engine) {
+    switch (engineType) {
       case 'aurora':
       case 'aurora-mysql':
       case 'mysql':
@@ -86,7 +86,7 @@ export class ProxyTarget {
         engineFamily = 'POSTGRESQL';
         break;
       default:
-        throw new Error(`Unsupported engine type - ${engine}`);
+        throw new Error(`Unsupported engine type - ${engineType}`);
     }
 
     return {

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

@@ -379,6 +379,7 @@ export = {
     const stack = testStack();
 
     const cluster = DatabaseCluster.fromDatabaseClusterAttributes(stack, 'Database', {
+      engine: DatabaseClusterEngine.auroraMysql({ version: AuroraMysqlEngineVersion.VER_2_08_1 }),
       clusterEndpointAddress: 'addr',
       clusterIdentifier: 'identifier',
       instanceEndpointAddresses: ['addr'],

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

@@ -549,6 +549,7 @@ export = {
     const stack = new cdk.Stack();
 
     const instance = rds.DatabaseInstance.fromDatabaseInstanceAttributes(stack, 'Database', {
+      engine: rds.DatabaseInstanceEngine.mysql({ version: rds.MysqlEngineVersion.VER_5_7_30 }),
       instanceEndpointAddress: 'address',
       instanceIdentifier: 'identifier',
       port: 3306,