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feat(aws-apigateway): API Gateway Construct Library (#665)
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Introduce an initial construct library for API Gateway. By all means it does not cover 
the entire surface area of API Gateway, but provides basic support for defining 
API gateway configurations (resources/methods hierarchy).

Integration support includes `LambdaIntegration` which accepts a `lambda.Function`, 
sets up the appropriate permissions and binds it to an API method.

Includes many "smart defaults" at every level such as:

- Automatically define a `Deployment` and a `Stage` for the API, which will be recreated every time the API configuration changes (by generating the logical ID of the AWS::ApiGateway::Deployment resource from a hash of the API configuration, similarly to SAM).
- Automatically configure a role for API Gateway to allow writing CloudWatch logs and alarms.
- Specify `defaultIntegration` at the API level which will apply to all methods without integration.

Supports defining APIs like this:

```ts
const integ = new apigw.LambdaIntegration(toysLambdaHandler);
const api = new apigw.RestApi(this, 'my-awesome-api');

api.root.onMethod('GET', new apigw.HttpIntegration('https://amazon.com/toys'));

const toys = api.root.addResource('toys', { defaultIntegration: integ });
toys.addMethod('ANY');

const toy = toys.addResource('{toy}');
toy.addMethod('GET'); // get a toy
toy.addMethod('DELETE'); // remove a toy
```

See [README] for more details.

[README]: https://github.com/awslabs/aws-cdk/blob/c99e7285e7b24700cfd4d52f6da32cffe12c511c/packages/%40aws-cdk/aws-apigateway/README.md

### Framework Changes

 * __resolve__: allow object keys to include tokens, as long as they resolvable to strings.
 * __assert__: invoke `stack.validateTree()` by default for `expect(stack)` to simulate synthesis.

----

* Features not supported yet are listed here: #727, #723
* Fixes #602, copy: @hassankhan
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Elad Ben-Israel authored Sep 17, 2018
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2 changes: 1 addition & 1 deletion packages/@aws-cdk/applet-js/package-lock.json

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25 changes: 19 additions & 6 deletions packages/@aws-cdk/assert/lib/expect.ts
Original file line number Diff line number Diff line change
Expand Up @@ -2,14 +2,27 @@ import cdk = require('@aws-cdk/cdk');
import api = require('@aws-cdk/cx-api');
import { StackInspector } from './inspector';

export function expect(stack: api.SynthesizedStack | cdk.Stack): StackInspector {
export function expect(stack: api.SynthesizedStack | cdk.Stack, skipValidation = false): StackInspector {
// Can't use 'instanceof' here, that breaks if we have multiple copies
// of this library.
const sstack: api.SynthesizedStack = isStackClassInstance(stack) ? {
name: 'test',
template: stack.toCloudFormation(),
metadata: {}
} : stack;
let sstack: api.SynthesizedStack;

if (isStackClassInstance(stack)) {
if (!skipValidation) {
const errors = stack.validateTree();
if (errors.length > 0) {
throw new Error(`Stack validation failed:\n${errors.map(e => `${e.message} at: ${e.source.parent}`).join('\n')}`);
}
}

sstack = {
name: 'test',
template: stack.toCloudFormation(),
metadata: {}
};
} else {
sstack = stack;
}

return new StackInspector(sstack);
}
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2 changes: 1 addition & 1 deletion packages/@aws-cdk/assert/package-lock.json

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167 changes: 165 additions & 2 deletions packages/@aws-cdk/aws-apigateway/README.md
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@@ -1,2 +1,165 @@
## The CDK Construct Library for AWS API Gateway
This module is part of the [AWS Cloud Development Kit](https://github.com/awslabs/aws-cdk) project.
## CDK Construct Library for Amazon API Gateway

Amazon API Gateway is a fully managed service that makes it easy for developers
to publish, maintain, monitor, and secure APIs at any scale. Create an API to
access data, business logic, or functionality from your back-end services, such
as applications running on Amazon Elastic Compute Cloud (Amazon EC2), code
running on AWS Lambda, or any web application.

### Defining APIs

APIs are defined as a hierarchy of resources and methods. `addResource` and
`addMethod` can be used to build this hierarchy. The root resource is
`api.root`.

For example, the following code defines an API that includes the following HTTP
endpoints: `ANY /, GET /books`, `POST /books`, `GET /books/{book_id}`, `DELETE /books/{book_id}`.

```ts
const api = new apigateway.RestApi(this, 'books-api');

api.root.addMethod('ANY');

const books = api.root.addResource('books');
books.addMethod('GET');
books.addMethod('POST');

const book = books.addResource('{book_id}');
book.addMethod('GET');
book.addMethod('DELETE');
```

### Integration Targets

Methods are associated with backend integrations, which are invoked when this
method is called. API Gateway supports the following integrations:

* `MockIntegration` - can be used to test APIs. This is the default
integration if one is not specified.
* `LambdaIntegration` - can be used to invoke an AWS Lambda function.
* `AwsIntegration` - can be used to invoke arbitrary AWS service APIs.
* `HttpIntegration` - can be used to invoke HTTP endpoints.

The following example shows how to integrate the `GET /book/{book_id}` method to
an AWS Lambda function:

```ts
const getBookHandler = new lambda.Function(...);
const getBookIntegration = new apigateway.LambdaIntegration(getBookHandler);
book.addMethod('GET', getBookIntegration);
```

Integration options can be optionally be specified:

```ts
const getBookIntegration = new apigateway.LambdaIntegration(getBookHandler, {
contentHandling: apigateway.ContentHandling.ConvertToText, // convert to base64
credentialsPassthrough: true, // use caller identity to invoke the function
});
```

Method options can optionally be specified when adding methods:

```ts
book.addMethod('GET', getBookIntegration, {
authorizationType: apigateway.AuthorizationType.IAM,
apiKeyRequired: true
});
```

#### Default Integration and Method Options

The `defaultIntegration` and `defaultMethodOptions` properties can be used to
configure a default integration at any resource level. These options will be
used when defining method under this resource (recursively) with undefined
integration or options.

> If not defined, the default integration is `MockIntegration`. See reference
documentation for default method options.

The following example defines the `booksBackend` integration as a default
integration. This means that all API methods that do not explicitly define an
integration will be routed to this AWS Lambda function.

```ts
const booksBackend = new apigateway.LambdaIntegration(...);
const api = new apigateway.RestApi(this, 'books', {
defaultIntegration: booksBackend
});

const books = new api.root.addResource('books');
books.addMethod('GET'); // integrated with `booksBackend`
books.addMethod('POST'); // integrated with `booksBackend`

const book = books.addResource('{book_id}');
book.addMethod('GET'); // integrated with `booksBackend`
```

### Deployments

By default, the `RestApi` construct will automatically create an API Gateway
[Deployment] and a "prod" [Stage] which represent the API configuration you
defined in your CDK app. This means that when you deploy your app, your API will
be have open access from the internet via the stage URL.

The URL of your API can be obtained from the attribute `restApi.url`, and is
also exported as an `Output` from your stack, so it's printed when you `cdk
deploy` your app:

```
$ cdk deploy
...
books.booksapiEndpointE230E8D5 = https://6lyktd4lpk.execute-api.us-east-1.amazonaws.com/prod/
```

To disable this behavior, you can set `{ deploy: false }` when creating your
API. This means that the API will not be deployed and a stage will not be
created for it. You will need to manually define a `apigateway.Deployment` and
`apigateway.Stage` resources.

Use the `deployOptions` property to customize the deployment options of your
API.

The following example will configure API Gateway to emit logs and data traces to
AWS CloudWatch for all API calls:

> By default, an IAM role will be created and associated with API Gateway to
allow it to write logs and metrics to AWS CloudWatch `cloudWatchRole` is set to
`false`.

```ts
const api = new apigateway.RestApi(this, 'books', {
deployOptions: {
loggingLevel: apigateway.MethodLoggingLevel.Info,
dataTraceEnabled: true
}
})
```

#### Deeper dive: invalidation of deployments

API Gateway deployments are an immutable snapshot of the API. This means that we
want to automatically create a new deployment resource every time the API model
defined in our CDK app changes.

In order to achieve that, the AWS CloudFormation logical ID of the
`AWS::ApiGateway::Deployment` resource is dynamically calculated by hashing the
API configuration (resources, methods). This means that when the configuration
changes (i.e. a resource or method are added, configuration is changed), a new
logical ID will be assigned to the deployment resource. This will cause
CloudFormation to create a new deployment resource.

By default, old deployments are _deleted_. You can set `retainDeployments: true`
to allow users revert the stage to an old deployment manually.

[Deployment]: https://docs.aws.amazon.com/apigateway/api-reference/resource/deployment/
[Stage]: https://docs.aws.amazon.com/apigateway/api-reference/resource/stage/

### Missing Features

See [awslabs/aws-cdk#723](https://github.com/awslabs/aws-cdk/issues/723) for a
list of missing features.

----

This module is part of the [AWS Cloud Development Kit](https://github.com/awslabs/aws-cdk) project.
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