feat(servicediscovery): AWS Cloud Map construct library (#1804)

Add a construct library for AWS Cloud Map.

Partially based on work by @jogold.

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

@@ -1,2 +1,34 @@
 ## The CDK Construct Library for AWS Service Discovery
 This module is part of the [AWS Cloud Development Kit](https://github.com/awslabs/aws-cdk) project.
+
+This package contains constructs for working with **AWS Cloud Map**
+
+AWS Cloud Map is a fully managed service that you can use to create and
+maintain a map of the backend services and resources that your applications
+depend on.
+
+For further information on AWS Cloud Map,
+see the [AWS Cloud Map documentation](https://docs.aws.amazon.com/cloud-map)
+
+The following example creates an AWS Cloud Map namespace that
+supports API calls, creates a service in that namespace, and
+registers an instance to it:
+
+[Creating a Cloud Map service within an HTTP namespace](test/integ.service-with-http-namespace.lit.ts)
+
+The following example creates an AWS Cloud Map namespace that
+supports both API calls and DNS queries within a vpc, creates a
+service in that namespace, and registers a loadbalancer as an
+instance:
+
+[Creating a Cloud Map service within a Private DNS namespace](test/integ.service-with-private-dns-namespace.lit.ts)
+
+The following example creates an AWS Cloud Map namespace that
+supports both API calls and public DNS queries, creates a service in
+that namespace, and registers an IP instance:
+
+[Creating a Cloud Map service within a Public namespace](test/integ.service-with-public-dns-namespace.lit.ts)
+
+For DNS namespaces, you can also register instances to services with CNAME records:
+
+[Creating a Cloud Map service within a Public namespace](test/integ.service-with-cname-record.lit.ts)

packages/@aws-cdk/aws-servicediscovery/lib/alias-target-instance.ts

@@ -0,0 +1,74 @@
+import cdk = require('@aws-cdk/cdk');
+import { BaseInstanceProps, InstanceBase } from './instance';
+import { NamespaceType } from './namespace';
+import { DnsRecordType, IService, RoutingPolicy } from './service';
+import { CfnInstance } from './servicediscovery.generated';
+
+/*
+ * Properties for an AliasTargetInstance
+ */
+export interface AliasTargetInstanceProps extends BaseInstanceProps {
+  /**
+   * DNS name of the target
+   */
+  dnsName: string;
+
+  /**
+   * The Cloudmap service this resource is registered to.
+   */
+  service: IService;
+}
+
+/*
+ * Instance that uses Route 53 Alias record type. Currently, the only resource types supported are Elastic Load
+ * Balancers.
+ */
+export class AliasTargetInstance extends InstanceBase {
+  /**
+   * The Id of the instance
+   */
+  public readonly instanceId: string;
+
+  /**
+   * The Cloudmap service to which the instance is registered.
+   */
+  public readonly service: IService;
+
+  /**
+   * The Route53 DNS name of the alias target
+   */
+  public readonly dnsName: string;
+
+  constructor(scope: cdk.Construct, id: string, props: AliasTargetInstanceProps) {
+    super(scope, id);
+
+    if (props.service.namespace.type === NamespaceType.Http) {
+      throw new Error('Namespace associated with Service must be a DNS Namespace.');
+    }
+
+    // Should already be enforced when creating service, but validates if service is not instantiated with #createService
+    const dnsRecordType = props.service.dnsRecordType;
+    if (dnsRecordType !== DnsRecordType.A
+      && dnsRecordType !== DnsRecordType.AAAA
+      && dnsRecordType !== DnsRecordType.A_AAAA) {
+      throw new Error('Service must use `A` or `AAAA` records to register an AliasRecordTarget.');
+    }
+
+    if (props.service.routingPolicy !== RoutingPolicy.Weighted) {
+      throw new Error('Service must use `WEIGHTED` routing policy.');
+    }
+
+    const resource = new CfnInstance(this, 'Resource', {
+      instanceAttributes: {
+        AWS_ALIAS_DNS_NAME: props.dnsName,
+        ...props.customAttributes
+      },
+      instanceId: props.instanceId || this.node.uniqueId,
+      serviceId: props.service.serviceId
+    });
+
+    this.service = props.service;
+    this.instanceId = resource.instanceId;
+    this.dnsName = props.dnsName;
+  }
+}

packages/@aws-cdk/aws-servicediscovery/lib/cname-instance.ts

@@ -0,0 +1,72 @@
+import cdk = require('@aws-cdk/cdk');
+import { BaseInstanceProps, InstanceBase } from './instance';
+import { NamespaceType } from './namespace';
+import { DnsRecordType, IService } from './service';
+import { CfnInstance } from './servicediscovery.generated';
+
+/*
+ * Properties for a CnameInstance used for service#registerCnameInstance
+ */
+export interface CnameInstanceBaseProps extends BaseInstanceProps {
+  /**
+   * If the service configuration includes a CNAME record, the domain name that you want Route 53 to
+   * return in response to DNS queries, for example, example.com. This value is required if the
+   * service specified by ServiceId includes settings for an CNAME record.
+   */
+  instanceCname: string;
+}
+
+/*
+ * Properties for a CnameInstance
+ */
+export interface CnameInstanceProps extends CnameInstanceBaseProps {
+  /**
+   * The Cloudmap service this resource is registered to.
+   */
+  service: IService;
+}
+
+/*
+ * Instance that is accessible using a domain name (CNAME).
+ */
+export class CnameInstance extends InstanceBase {
+  /**
+   * The Id of the instance
+   */
+  public readonly instanceId: string;
+
+  /**
+   * The Cloudmap service to which the instance is registered.
+   */
+  public readonly service: IService;
+
+  /**
+   * The domain name returned by DNS queries for the instance
+   */
+  public readonly instanceCname: string;
+
+  constructor(scope: cdk.Construct, id: string, props: CnameInstanceProps) {
+    super(scope, id);
+
+    if (props.service.namespace.type === NamespaceType.Http) {
+      throw new Error('Namespace associated with Service must be a DNS Namespace.');
+    }
+
+    if (props.service.dnsRecordType !== DnsRecordType.CNAME) {
+      throw new Error('A `CnameIntance` can only be used with a service using a `CNAME` record.');
+    }
+
+    const resource = new CfnInstance(this, 'Resource', {
+      instanceId: props.instanceId || this.uniqueInstanceId(),
+      serviceId: props.service.serviceId,
+      instanceAttributes: {
+        AWS_INSTANCE_CNAME: props.instanceCname,
+        ...props.customAttributes
+      }
+    });
+
+    this.service = props.service;
+    this.instanceId = resource.instanceId;
+    this.instanceCname = props.instanceCname;
+  }
+}

packages/@aws-cdk/aws-servicediscovery/lib/http-namespace.ts

@@ -0,0 +1,56 @@
+import cdk = require('@aws-cdk/cdk');
+import { BaseNamespaceProps, NamespaceBase, NamespaceType } from './namespace';
+import { BaseServiceProps, Service } from './service';
+import { CfnHttpNamespace } from './servicediscovery.generated';
+
+// tslint:disable:no-empty-interface
+export interface HttpNamespaceProps extends BaseNamespaceProps {}
+
+/**
+ * Define an HTTP Namespace
+ */
+export class HttpNamespace extends NamespaceBase {
+  /**
+   * A name for the namespace.
+   */
+  public readonly namespaceName: string;
+
+  /**
+   * Namespace Id for the namespace.
+   */
+  public readonly namespaceId: string;
+
+  /**
+   * Namespace Arn for the namespace.
+   */
+  public readonly namespaceArn: string;
+
+  /**
+   * Type of the namespace.
+   */
+  public readonly type: NamespaceType;
+
+  constructor(scope: cdk.Construct, id: string, props: HttpNamespaceProps) {
+    super(scope, id);
+
+    const ns = new CfnHttpNamespace(this, 'Resource', {
+      name: props.name,
+      description: props.description
+    });
+
+    this.namespaceName = props.name;
+    this.namespaceId = ns.httpNamespaceId;
+    this.namespaceArn = ns.httpNamespaceArn;
+    this.type = NamespaceType.Http;
+  }
+
+  /**
+   * Creates a service within the namespace
+   */
+  public createService(id: string, props?: BaseServiceProps): Service {
+    return new Service(this, id, {
+      namespace: this,
+      ...props
+    });
+  }
+}

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

@@ -1,2 +1,12 @@
+export * from './instance';
+export * from './alias-target-instance';
+export * from './cname-instance';
+export * from './ip-instance';
+export * from './non-ip-instance';
+export * from './namespace';
+export * from './http-namespace';
+export * from './private-dns-namespace';
+export * from './public-dns-namespace';
+export * from './service';
 // AWS::ServiceDiscovery CloudFormation Resources:
 export * from './servicediscovery.generated';

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

@@ -0,0 +1,55 @@
+import cdk = require('@aws-cdk/cdk');
+import { IService } from './service';
+
+export interface IInstance extends cdk.IConstruct {
+  /**
+   * The id of the instance resource
+   */
+  readonly instanceId: string;
+
+  /**
+   * The Cloudmap service this resource is registered to.
+   */
+  readonly service: IService;
+}
+
+/**
+ * Used when the resource that's associated with the service instance is accessible using values other than an IP
+ * address or a domain name (CNAME), i.e. for non-ip-instances
+ */
+export interface BaseInstanceProps {
+  /**
+   * The id of the instance resource
+   *
+   * @default Automatically generated name
+   */
+  instanceId?: string;
+
+  /**
+   * Custom attributes of the instance.
+   *
+   * @default none
+   */
+  customAttributes?: { [key: string]: string };
+}
+
+export abstract class InstanceBase extends cdk.Construct implements IInstance {
+  /**
+   * The Id of the instance
+   */
+  public abstract readonly instanceId: string;
+
+  /**
+   * The Cloudmap service to which the instance is registered.
+   */
+  public abstract readonly service: IService;
+
+  /**
+   * Generate a unique instance Id that is safe to pass to CloudMap
+   */
+  protected uniqueInstanceId() {
+    // Max length of 64 chars, get the last 64 chars
+    const id = this.node.uniqueId;
+    return id.substring(Math.max(id.length - 64, 0), id.length);
+  }
+}