feat(appsync): import existing graphql api

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

@@ -81,6 +81,23 @@ demoDS.createResolver({
 });
 ```
 
+## Imports
+
+Any GraphQL Api can be imported from another stack. Utilizing the `fromXxx`
+functions, you have the ability to add data sources and resolvers through
+a `IGraphQLApi` interface.
+
+```ts
+const importedApi = appsync.GraphQLApi.fromGraphQLApiId(...);
+importedApi.addDynamoDbDataSource(...);
+```
+
+GraphQL Apis can be imported in three ways:
+- `arn` through `GraphQLApi.fromGraphQLApiArn`: `apiId` is generated from parameter
+- `apiId` through `GraphQLApi.fromGraphQLApiId`: `arn` is generated from parameter
+- or both through `GraphQLApi.fromGraphQLApiAttributes`: both are specified
+
+
 ## Permissions
 
 When using `AWS_IAM` as the authorization type for GraphQL API, an IAM Role

packages/@aws-cdk/aws-appsync/lib/data-source.ts

@@ -3,7 +3,7 @@ import { IGrantable, IPrincipal, IRole, Role, ServicePrincipal } from '@aws-cdk/
 import { IFunction } from '@aws-cdk/aws-lambda';
 import { Construct, IResolvable } from '@aws-cdk/core';
 import { CfnDataSource } from './appsync.generated';
-import { GraphQLApi } from './graphqlapi';
+import { IGraphQLApi } from './graphqlapi-base';
 import { BaseResolverProps, Resolver } from './resolver';
 
 /**
@@ -13,7 +13,7 @@ export interface BaseDataSourceProps {
   /**
    * The API to attach this data source to
    */
-  readonly api: GraphQLApi;
+  readonly api: IGraphQLApi;
   /**
    * The name of the data source
    */
@@ -91,7 +91,7 @@ export abstract class BaseDataSource extends Construct {
    */
   public readonly ds: CfnDataSource;
 
-  protected api: GraphQLApi;
+  protected api: IGraphQLApi;
   protected serviceRole?: IRole;
 
   constructor(scope: Construct, id: string, props: BackedDataSourceProps, extended: ExtendedDataSourceProps) {

packages/@aws-cdk/aws-appsync/lib/graphqlapi-base.ts

@@ -0,0 +1,142 @@
+import { ITable } from '@aws-cdk/aws-dynamodb';
+import { IFunction } from '@aws-cdk/aws-lambda';
+import { CfnResource, IResource, Resource } from '@aws-cdk/core';
+import { DynamoDbDataSource, HttpDataSource, LambdaDataSource, NoneDataSource } from './data-source';
+/**
+ * Interface for GraphQL
+ */
+export interface IGraphQLApi extends IResource {
+  /**
+   * the id of the GraphQL API
+   *
+   * @attribute
+   */
+  readonly apiId: string;
+  /**
+   * the ARN of the API
+   *
+   * @attribute
+   */
+  readonly arn: string;
+  /**
+   * add a new dummy data source to this API
+   * @param name The name of the data source
+   * @param description The description of the data source
+   */
+  addNoneDataSource(name: string, description: string): NoneDataSource;
+
+  /**
+   * add a new DynamoDB data source to this API
+   * @param name The name of the data source
+   * @param description The description of the data source
+   * @param table The DynamoDB table backing this data source [disable-awslint:ref-via-interface]
+   */
+  addDynamoDbDataSource( name: string, description: string, table: ITable ): DynamoDbDataSource;
+
+  /**
+   * add a new http data source to this API
+   * @param name The name of the data source
+   * @param description The description of the data source
+   * @param endpoint The http endpoint
+   */
+  addHttpDataSource(name: string, description: string, endpoint: string): HttpDataSource;
+
+  /**
+   * add a new Lambda data source to this API
+   * @param name The name of the data source
+   * @param description The description of the data source
+   * @param lambdaFunction The Lambda function to call to interact with this data source
+   */
+  addLambdaDataSource( name: string, description: string, lambdaFunction: IFunction ): LambdaDataSource;
+
+  /**
+   * Add schema dependency if not imported
+   * @param construct the construct that has a dependency
+   */
+  addSchemaDependency( construct: CfnResource ): boolean;
+}
+
+/**
+ * Base Class for GraphQL API
+ */
+export abstract class GraphQLApiBase extends Resource implements IGraphQLApi {
+  /**
+   * the id of the GraphQL API
+   */
+  public abstract readonly apiId: string;
+  /**
+   * the ARN of the API
+   */
+  public abstract readonly arn: string;
+
+  /**
+   * add a new dummy data source to this API
+   * @param name The name of the data source
+   * @param description The description of the data source
+   */
+  public addNoneDataSource(name: string, description: string): NoneDataSource {
+    return new NoneDataSource(this, `${name}DS`, {
+      api: this,
+      description,
+      name,
+    });
+  }
+
+  /**
+   * add a new DynamoDB data source to this API
+   * @param name The name of the data source
+   * @param description The description of the data source
+   * @param table The DynamoDB table backing this data source [disable-awslint:ref-via-interface]
+   */
+  public addDynamoDbDataSource(
+    name: string,
+    description: string,
+    table: ITable,
+  ): DynamoDbDataSource {
+    return new DynamoDbDataSource(this, `${name}DS`, {
+      api: this,
+      description,
+      name,
+      table,
+    });
+  }
+
+  /**
+   * add a new http data source to this API
+   * @param name The name of the data source
+   * @param description The description of the data source
+   * @param endpoint The http endpoint
+   */
+  public addHttpDataSource(name: string, description: string, endpoint: string): HttpDataSource {
+    return new HttpDataSource(this, `${name}DS`, {
+      api: this,
+      description,
+      endpoint,
+      name,
+    });
+  }
+
+  /**
+   * add a new Lambda data source to this API
+   * @param name The name of the data source
+   * @param description The description of the data source
+   * @param lambdaFunction The Lambda function to call to interact with this data source
+   */
+  public addLambdaDataSource( name: string, description: string, lambdaFunction: IFunction ): LambdaDataSource {
+    return new LambdaDataSource(this, `${name}DS`, {
+      api: this,
+      description,
+      name,
+      lambdaFunction,
+    });
+  }
+
+  /**
+   * Add schema dependency if not imported
+   * @param construct the construct that has a dependency
+   */
+  public addSchemaDependency( construct: CfnResource ): boolean {
+    construct;
+    return false;
+  }
+}

packages/@aws-cdk/aws-appsync/lib/graphqlapi.ts

@@ -1,11 +1,9 @@
 import { readFileSync } from 'fs';
 import { IUserPool } from '@aws-cdk/aws-cognito';
-import { ITable } from '@aws-cdk/aws-dynamodb';
-import { Grant, IGrantable, ManagedPolicy, Role, ServicePrincipal } from '@aws-cdk/aws-iam';
-import { IFunction } from '@aws-cdk/aws-lambda';
-import { Construct, Duration, IResolvable, Stack } from '@aws-cdk/core';
-import { CfnApiKey, CfnGraphQLApi, CfnGraphQLSchema } from './appsync.generated';
-import { DynamoDbDataSource, HttpDataSource, LambdaDataSource, NoneDataSource } from './data-source';
+import { ManagedPolicy, Role, ServicePrincipal, Grant, IGrantable } from '@aws-cdk/aws-iam';
+import { CfnResource, Construct, Duration, Fn, IResolvable, Stack } from '@aws-cdk/core';
+import { CfnApiKey,  CfnGraphQLApi,  CfnGraphQLSchema } from './appsync.generated';
+import { IGraphQLApi, GraphQLApiBase } from './graphqlapi-base';
 
 /**
  * enum with all possible values for AppSync authorization type
@@ -206,7 +204,6 @@ export interface LogConfig {
  * Properties for an AppSync GraphQL API
  */
 export interface GraphQLApiProps {
-
   /**
    * the name of the GraphQL API
    */
@@ -300,11 +297,71 @@ export class IamResource {
   }
 }
 
+/**
+ * Attributes for GraphQL From
+ */
+export interface GraphQLApiAttributes {
+  /**
+   * the arn for the GraphQL Api
+   */
+  readonly arn: string,
+
+  /**
+   * the api id of the GraphQL Api
+   */
+  readonly apiId: string,
+}
+
 /**
  * An AppSync GraphQL API
+ *
+ * @resource AWS::AppSync::GraphQLApi
  */
-export class GraphQLApi extends Construct {
+export class GraphQLApi extends GraphQLApiBase {
+  /**
+   * Import a GraphQL API given an arn
+   * @param scope scope
+   * @param id id
+   * @param graphQLApiId the apiId of the api
+   */
+  public static fromGraphQLApiId(scope: Construct, id: string, graphQLApiId: string): IGraphQLApi {
+    const generatedArn = Stack.of(scope).formatArn({
+      service: 'appsync',
+      resource: `apis/${graphQLApiId}`,
+    });
+    return GraphQLApi.fromGraphQLApiAttributes(scope, id, { arn: generatedArn, apiId: graphQLApiId});
+  }
+
+  /**
+   * Import a GraphQL API given an arn
+   * @param scope scope
+   * @param id id
+   * @param graphQLApiArn the arn of the api
+   */
+  public static fromGraphQLApiArn(scope: Construct, id: string, graphQLApiArn: string): IGraphQLApi {
+    const apiId = Fn.select(1, Fn.split('/', graphQLApiArn));
+    if (apiId == undefined || apiId == graphQLApiArn) {
+      throw Error('Arn does not contain a valid apiId');
+    }
+    return GraphQLApi.fromGraphQLApiAttributes(scope, id, { arn: graphQLApiArn, apiId: apiId});
+  }
 
+  /**
+   * Import a GraphQL API through this function
+   * @param scope scope
+   * @param id id
+   * @param attrs GraphQL API Attributes of an API
+   */
+  public static fromGraphQLApiAttributes(scope: Construct, id: string, attrs: GraphQLApiAttributes): IGraphQLApi {
+    class Import extends GraphQLApiBase {
+      public readonly apiId = attrs.apiId;
+      public readonly arn = attrs.arn;
+      constructor (s: Construct, i: string){
+        super(s, i);
+      }
+    }
+    return new Import(scope, id);
+  }
   /**
    * the id of the GraphQL API
    */
@@ -315,6 +372,8 @@ export class GraphQLApi extends Construct {
   public readonly arn: string;
   /**
    * the URL of the endpoint created by AppSync
+   *
+   * @attribute
    */
   public readonly graphQlUrl: string;
   /**
@@ -418,72 +477,6 @@ export class GraphQLApi extends Construct {
     });
   }
 
-  /**
-   * add a new dummy data source to this API
-   * @param name The name of the data source
-   * @param description The description of the data source
-   */
-  public addNoneDataSource(name: string, description: string): NoneDataSource {
-    return new NoneDataSource(this, `${name}DS`, {
-      api: this,
-      description,
-      name,
-    });
-  }
-
-  /**
-   * add a new DynamoDB data source to this API
-   * @param name The name of the data source
-   * @param description The description of the data source
-   * @param table The DynamoDB table backing this data source [disable-awslint:ref-via-interface]
-   */
-  public addDynamoDbDataSource(
-    name: string,
-    description: string,
-    table: ITable,
-  ): DynamoDbDataSource {
-    return new DynamoDbDataSource(this, `${name}DS`, {
-      api: this,
-      description,
-      name,
-      table,
-    });
-  }
-
-  /**
-   * add a new http data source to this API
-   * @param name The name of the data source
-   * @param description The description of the data source
-   * @param endpoint The http endpoint
-   */
-  public addHttpDataSource(name: string, description: string, endpoint: string): HttpDataSource {
-    return new HttpDataSource(this, `${name}DS`, {
-      api: this,
-      description,
-      endpoint,
-      name,
-    });
-  }
-
-  /**
-   * add a new Lambda data source to this API
-   * @param name The name of the data source
-   * @param description The description of the data source
-   * @param lambdaFunction The Lambda function to call to interact with this data source
-   */
-  public addLambdaDataSource(
-    name: string,
-    description: string,
-    lambdaFunction: IFunction,
-  ): LambdaDataSource {
-    return new LambdaDataSource(this, `${name}DS`, {
-      api: this,
-      description,
-      name,
-      lambdaFunction,
-    });
-  }
-
   /**
    * Adds an IAM policy statement associated with this GraphQLApi to an IAM
    * principal's policy.
@@ -597,6 +590,15 @@ export class GraphQLApi extends Construct {
     }
   }
 
+  /**
+   * Add schema dependency if not imported
+   * @param construct the construct that has a dependency
+   */
+  public addSchemaDependency( construct: CfnResource ): boolean {
+    construct.addDependsOn(this.schema);
+    return true;
+  }
+
   private formatOpenIdConnectConfig(
     config: OpenIdConnectConfig,
   ): CfnGraphQLApi.OpenIDConnectConfigProperty {
@@ -666,4 +668,4 @@ export class GraphQLApi extends Construct {
     const authModes = props.authorizationConfig?.additionalAuthorizationModes;
     return authModes ? this.formatAdditionalAuthorizationModes(authModes) : undefined;
   }
-}
+}