feat(rds): Add InstanceParameterGroup

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

@@ -291,6 +291,8 @@ export class DatabaseCluster extends DatabaseClusterBase implements IDatabaseClu
 
       const publiclyAccessible = props.instanceProps.vpcSubnets && props.instanceProps.vpcSubnets.subnetType === ec2.SubnetType.Public;
 
+      const instanceParameterGroupName = props.instanceProps.parameterGroup && props.instanceProps.parameterGroup.parameterGroupName;
+
       const instance = new CfnDBInstance(this, `Instance${instanceIndex}`, {
         // Link to cluster
         engine: props.engine,
@@ -301,6 +303,7 @@ export class DatabaseCluster extends DatabaseClusterBase implements IDatabaseClu
         publiclyAccessible,
         // This is already set on the Cluster. Unclear to me whether it should be repeated or not. Better yes.
         dbSubnetGroupName: subnetGroup.ref,
+        dbParameterGroupName: instanceParameterGroupName,
       });
 
       // We must have a dependency on the NAT gateway provider here to create

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

@@ -5,6 +5,7 @@ export * from './props';
 export * from './cluster-parameter-group';
 export * from './rotation-single-user';
 export * from './database-secret';
+export * from './instance-parameter-group';
 
 // AWS::RDS CloudFormation Resources:
 export * from './rds.generated';

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

@@ -0,0 +1,134 @@
+import { CfnOutput, Construct, IConstruct, Token } from '@aws-cdk/cdk';
+import { Parameters } from './props';
+import { CfnDBParameterGroup } from './rds.generated';
+
+/**
+ * A instance parameter group
+ */
+export interface IInstanceParameterGroup extends IConstruct {
+  /**
+   * Name of this parameter group
+   */
+  readonly parameterGroupName: string;
+
+  /**
+   * Export this parameter group
+   */
+  export(): InstanceParameterGroupImportProps;
+}
+
+/**
+ * Properties to reference a instance parameter group
+ */
+export interface InstanceParameterGroupImportProps {
+  readonly parameterGroupName: string;
+}
+
+/**
+ * Properties for a instance parameter group
+ */
+export interface InstanceParameterGroupProps {
+  /**
+   * Database family of this parameter group
+   *
+   * @see https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBParameterGroup.html#API_CreateDBParameterGroup_RequestParameters
+   * @example
+   * { family: 'MySQL5.5' }
+   */
+  family: string;
+
+  /**
+   * Description for this parameter group
+   */
+  description: string;
+
+  /**
+   * The parameters in this parameter group
+   */
+  parameters: Parameters;
+}
+
+/**
+ * Defina a instance parameter group
+ */
+export class InstanceParameterGroup extends Construct implements IInstanceParameterGroup {
+  /**
+   * Import a parameter group
+   */
+  public static import(scope: Construct, id: string, props: InstanceParameterGroupImportProps): IInstanceParameterGroup {
+    return new ImportedInstanceParameterGroup(scope, id, props);
+  }
+
+  public readonly parameterGroupName: string;
+  private readonly parameters: Parameters = {};
+
+  constructor(scope: Construct, id: string, props: InstanceParameterGroupProps) {
+    super(scope, id);
+
+    const { description, family, parameters } = props;
+
+    const resource = new CfnDBParameterGroup(this, 'Resource', {
+      description,
+      family,
+      parameters: new Token(() => this.parameters)
+    });
+
+    for (const [key, value] of Object.entries(parameters || {})) {
+      this.setParameter(key, value);
+    }
+
+    this.parameterGroupName = resource.dbParameterGroupName;
+  }
+
+  /**
+   * Export this parameter group
+   */
+  public export(): InstanceParameterGroupImportProps {
+    return {
+      parameterGroupName: new CfnOutput(this, 'ParameterGroupName', { value: this.parameterGroupName }).makeImportValue().toString(),
+    };
+  }
+
+  /**
+   * Set a single parameter in this parameter group
+   */
+  public setParameter(key: string, value: string | undefined) {
+    if (value === undefined && key in this.parameters) {
+      delete this.parameters[key];
+    }
+    if (value !== undefined) {
+      this.parameters[key] = value;
+    }
+  }
+
+  /**
+   * Remove a previously-set parameter from this parameter group
+   */
+  public removeParameter(key: string) {
+    this.setParameter(key, undefined);
+  }
+
+  /**
+   * Validate this construct
+   */
+  protected validate(): string[] {
+    if (Object.keys(this.parameters).length === 0) {
+      return ['At least one parameter required, call setParameter().'];
+    }
+    return [];
+  }
+}
+
+class ImportedInstanceParameterGroup extends Construct implements IInstanceParameterGroup {
+  public readonly parameterGroupName: string;
+
+  constructor(scope: Construct, id: string, private readonly props: InstanceParameterGroupImportProps) {
+    super(scope, id);
+
+    this.parameterGroupName = props.parameterGroupName;
+  }
+
+  public export() {
+    return this.props;
+  }
+}

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

@@ -1,5 +1,6 @@
 import ec2 = require('@aws-cdk/aws-ec2');
 import kms = require('@aws-cdk/aws-kms');
+import { IInstanceParameterGroup } from './instance-parameter-group';
 
 /**
  * The engine for the database cluster
@@ -36,6 +37,13 @@ export interface InstanceProps {
    * Security group. If not specified a new one will be created.
    */
   securityGroup?: ec2.ISecurityGroup;
+
+  /**
+   * Additional parameters to pass to the database instance
+   *
+   * @default No parameter group
+   */
+  parameterGroup?: IInstanceParameterGroup;
 }
 
 /**

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

@@ -2,7 +2,7 @@ import { expect, haveResource } from '@aws-cdk/assert';
 import ec2 = require('@aws-cdk/aws-ec2');
 import cdk = require('@aws-cdk/cdk');
 import { Test } from 'nodeunit';
-import { ClusterParameterGroup, DatabaseCluster, DatabaseClusterEngine } from '../lib';
+import { ClusterParameterGroup, DatabaseCluster, DatabaseClusterEngine, InstanceParameterGroup } from '../lib';
 
 export = {
   'check that instantiation works'(test: Test) {
@@ -160,6 +160,44 @@ export = {
     test.done();
   },
 
+  'cluster with instance parameter group'(test: Test) {
+    // GIVEN
+    const stack = testStack();
+    const vpc = new ec2.VpcNetwork(stack, 'VPC');
+
+    // WHEN
+    const instanceParameterGroup = new InstanceParameterGroup(stack, 'Params', {
+      family: 'mysql',
+      description: 'bye',
+      parameters: {},
+    });
+    instanceParameterGroup.setParameter('param1', 'value1');
+    instanceParameterGroup.setParameter('param2', 'value2');
+    instanceParameterGroup.removeParameter('param2');
+    new DatabaseCluster(stack, 'Database', {
+      engine: DatabaseClusterEngine.Aurora,
+      masterUser: {
+        username: 'admin',
+        password: 'tooshort',
+      },
+      instances: 1,
+      instanceProps: {
+        instanceType: new ec2.InstanceTypePair(ec2.InstanceClass.Burstable2, ec2.InstanceSize.Small),
+        parameterGroup: instanceParameterGroup,
+        vpc
+      },
+    });
+
+    // THEN
+    expect(stack).to(haveResource('AWS::RDS::DBInstance', {
+      DBParameterGroupName: {
+        Ref: 'ParamsA8366201',
+      },
+    }));
+
+    test.done();
+  },
+
   'import/export cluster parameter group'(test: Test) {
     // GIVEN
     const stack = testStack();
@@ -178,6 +216,25 @@ export = {
     test.done();
   },
 
+  'import/export instance parameter group'(test: Test) {
+    // GIVEN
+    const stack = testStack();
+    const group = new InstanceParameterGroup(stack, 'Params', {
+      family: 'hello',
+      description: 'desc',
+      parameters: {},
+    });
+
+    // WHEN
+    const exported = group.export();
+    const imported = InstanceParameterGroup.import(stack, 'ImportParams', exported);
+
+    // THEN
+    test.deepEqual(stack.node.resolve(exported), { parameterGroupName: { 'Fn::ImportValue': 'Stack:ParamsParameterGroupNameA6B808D7' } });
+    test.deepEqual(stack.node.resolve(imported.parameterGroupName), { 'Fn::ImportValue': 'Stack:ParamsParameterGroupNameA6B808D7' });
+    test.done();
+  },
+
   'creates a secret when master credentials are not specified'(test: Test) {
     // GIVEN
     const stack = testStack();
@@ -233,7 +290,21 @@ export = {
     }));
 
     test.done();
-  }
+  },
+
+  'empty instance parameter group is not valid'(test: Test) {
+    const stack = testStack();
+    new InstanceParameterGroup(stack, 'Params', {
+      family: 'hello',
+      description: 'desc',
+      parameters: {},
+    });
+
+    const errorMessages = stack.node.validateTree().map(e => e.message);
+    test.deepEqual(errorMessages, ['At least one parameter required, call setParameter().']);
+
+    test.done();
+  },
 };
 
 function testStack() {