fix(stepfunctions): Downscope SageMaker permissions (aws#2991)

Previous implementation was using the `SageMakerFullAccess` managed
policy, which grants extensive permissions to the SageMaker job.
Instead, this commit makes it set permissions very specifically to what
the requirement entities are, and only resorts to the `*` resource when
the entities are provided by an input to the StepFunction.

packages/@aws-cdk/aws-stepfunctions-tasks/lib/sagemaker-task-base-types.ts

@@ -1,6 +1,13 @@
 import ec2 = require('@aws-cdk/aws-ec2');
+import ecr = require('@aws-cdk/aws-ecr');
+import { DockerImageAsset, DockerImageAssetProps } from '@aws-cdk/aws-ecr-assets';
+import iam = require('@aws-cdk/aws-iam');
 import kms = require('@aws-cdk/aws-kms');
-import { Duration } from '@aws-cdk/core';
+import s3 = require('@aws-cdk/aws-s3');
+import sfn = require('@aws-cdk/aws-stepfunctions');
+import { Construct, Duration } from '@aws-cdk/core';
+
+export interface ISageMakerTask extends sfn.IStepFunctionsTask, iam.IGrantable {}
 
 //
 // Create Training Job types
@@ -24,7 +31,7 @@ export interface AlgorithmSpecification {
     /**
      * Registry path of the Docker image that contains the training algorithm.
      */
-    readonly trainingImage?: string;
+    readonly trainingImage?: DockerImage;
 
     /**
      * Input mode that the algorithm supports.
@@ -125,7 +132,7 @@ export interface S3DataSource {
     /**
      * S3 Uri
      */
-    readonly s3Uri: string;
+    readonly s3Location: S3Location;
 }
 
 /**
@@ -140,16 +147,22 @@ export interface OutputDataConfig {
   /**
    * Identifies the S3 path where you want Amazon SageMaker to store the model artifacts.
    */
-  readonly s3OutputPath: string;
+  readonly s3OutputLocation: S3Location;
 }
 
+/**
+ * @experimental
+ */
 export interface StoppingCondition {
     /**
      * The maximum length of time, in seconds, that the training or compilation job can run.
      */
     readonly maxRuntime?: Duration;
 }
 
+/**
+ * @experimental
+ */
 export interface ResourceConfig {
 
     /**
@@ -169,7 +182,7 @@ export interface ResourceConfig {
     /**
      * KMS key that Amazon SageMaker uses to encrypt data on the storage volume attached to the ML compute instance(s) that run the training job.
      */
-    readonly volumeKmsKeyId?: kms.IKey;
+    readonly volumeEncryptionKey?: kms.IKey;
 
     /**
      * Size of the ML storage volume that you want to provision.
@@ -218,8 +231,139 @@ export interface MetricDefinition {
     readonly regex: string;
 }
 
+/**
+ * @experimental
+ */
+export interface S3LocationConfig {
+    readonly uri: string;
+}
+
+/**
+ * Constructs `IS3Location` objects.
+ *
+ * @experimental
+ */
+export abstract class S3Location {
+    /**
+     * An `IS3Location` built with a determined bucket and key prefix.
+     *
+     * @param bucket    is the bucket where the objects are to be stored.
+     * @param keyPrefix is the key prefix used by the location.
+     */
+    public static fromBucket(bucket: s3.IBucket, keyPrefix: string): S3Location {
+        return new StandardS3Location({ bucket, keyPrefix, uri: bucket.urlForObject(keyPrefix) });
+    }
+
+    /**
+     * An `IS3Location` determined fully by a JSON Path from the task input.
+     *
+     * Due to the dynamic nature of those locations, the IAM grants that will be set by `grantRead` and `grantWrite`
+     * apply to the `*` resource.
+     *
+     * @param expression the JSON expression resolving to an S3 location URI.
+     */
+    public static fromJsonExpression(expression: string): S3Location {
+        return new StandardS3Location({ uri: sfn.Data.stringAt(expression) });
+    }
+
+    /**
+     * Called when the S3Location is bound to a StepFunctions task.
+     */
+    public abstract bind(task: ISageMakerTask, opts: S3LocationBindOptions): S3LocationConfig;
+}
+
+/**
+ * Options for binding an S3 Location.
+ *
+ * @experimental
+ */
+export interface S3LocationBindOptions {
+    /**
+     * Allow reading from the S3 Location.
+     *
+     * @default false
+     */
+    readonly forReading?: boolean;
+
+    /**
+     * Allow writing to the S3 Location.
+     *
+     * @default false
+     */
+    readonly forWriting?: boolean;
+}
+
+/**
+ * Configuration for a using Docker image.
+ *
+ * @experimental
+ */
+export interface DockerImageConfig {
+    /**
+     * The fully qualified URI of the Docker image.
+     */
+    readonly imageUri: string;
+}
+
+/**
+ * Creates `IDockerImage` instances.
+ *
+ * @experimental
+ */
+export abstract class DockerImage {
+    /**
+     * Reference a Docker image stored in an ECR repository.
+     *
+     * @param repository the ECR repository where the image is hosted.
+     * @param tag an optional `tag`
+     */
+    public static fromEcrRepository(repository: ecr.IRepository, tag: string = 'latest'): DockerImage {
+        return new StandardDockerImage({ repository, imageUri: repository.repositoryUriForTag(tag) });
+    }
+
+    /**
+     * Reference a Docker image which URI is obtained from the task's input.
+     *
+     * @param expression           the JSON path expression with the task input.
+     * @param allowAnyEcrImagePull whether ECR access should be permitted (set to `false` if the image will never be in ECR).
+     */
+    public static fromJsonExpression(expression: string, allowAnyEcrImagePull = true): DockerImage {
+        return new StandardDockerImage({ imageUri: expression, allowAnyEcrImagePull });
+    }
+
+    /**
+     * Reference a Docker image by it's URI.
+     *
+     * When referencing ECR images, prefer using `inEcr`.
+     *
+     * @param imageUri the URI to the docker image.
+     */
+    public static fromRegistry(imageUri: string): DockerImage {
+        return new StandardDockerImage({ imageUri });
+    }
+
+    /**
+     * Reference a Docker image that is provided as an Asset in the current app.
+     *
+     * @param scope the scope in which to create the Asset.
+     * @param id    the ID for the asset in the construct tree.
+     * @param props the configuration props of the asset.
+     */
+    public static fromAsset(scope: Construct, id: string, props: DockerImageAssetProps): DockerImage {
+        const asset = new DockerImageAsset(scope, id, props);
+        return new StandardDockerImage({ repository: asset.repository, imageUri: asset.imageUri });
+    }
+
+    /**
+     * Called when the image is used by a SageMaker task.
+     */
+    public abstract bind(task: ISageMakerTask): DockerImageConfig;
+}
+
 /**
  * S3 Data Type.
+ *
+ * @experimental
  */
 export enum S3DataType {
     /**
@@ -240,6 +384,8 @@ export enum S3DataType {
 
 /**
  * S3 Data Distribution Type.
+ *
+ * @experimental
  */
 export enum S3DataDistributionType {
     /**
@@ -255,6 +401,8 @@ export enum S3DataDistributionType {
 
 /**
  * Define the format of the input data.
+ *
+ * @experimental
  */
 export enum RecordWrapperType {
     /**
@@ -270,6 +418,8 @@ export enum RecordWrapperType {
 
 /**
  *  Input mode that the algorithm supports.
+ *
+ * @experimental
  */
 export enum InputMode {
     /**
@@ -285,6 +435,8 @@ export enum InputMode {
 
 /**
  * Compression type of the data.
+ *
+ * @experimental
  */
 export enum CompressionType {
     /**
@@ -416,6 +568,8 @@ export interface TransformResources {
 
 /**
  * Specifies the number of records to include in a mini-batch for an HTTP inference request.
+ *
+ * @experimental
  */
 export enum BatchStrategy {
 
@@ -432,6 +586,8 @@ export enum BatchStrategy {
 
 /**
  * Method to use to split the transform job's data files into smaller batches.
+ *
+ * @experimental
  */
 export enum SplitType {
 
@@ -458,6 +614,8 @@ export enum SplitType {
 
 /**
  * How to assemble the results of the transform job as a single S3 object.
+ *
+ * @experimental
  */
 export enum AssembleWith {
 
@@ -472,3 +630,70 @@ export enum AssembleWith {
     LINE = 'Line'
 
 }
+
+class StandardDockerImage extends DockerImage {
+    private readonly allowAnyEcrImagePull: boolean;
+    private readonly imageUri: string;
+    private readonly repository?: ecr.IRepository;
+
+    constructor(opts: { allowAnyEcrImagePull?: boolean, imageUri: string, repository?: ecr.IRepository }) {
+        super();
+
+        this.allowAnyEcrImagePull = !!opts.allowAnyEcrImagePull;
+        this.imageUri = opts.imageUri;
+        this.repository = opts.repository;
+    }
+
+    public bind(task: ISageMakerTask): DockerImageConfig {
+        if (this.repository) {
+            this.repository.grantPull(task);
+        }
+        if (this.allowAnyEcrImagePull) {
+            task.grantPrincipal.addToPolicy(new iam.PolicyStatement({
+                actions: [
+                    'ecr:BatchCheckLayerAvailability',
+                    'ecr:GetDownloadUrlForLayer',
+                    'ecr:BatchGetImage',
+                ],
+                resources: ['*']
+            }));
+        }
+        return {
+            imageUri: this.imageUri,
+        };
+    }
+}
+
+class StandardS3Location extends S3Location {
+    private readonly bucket?: s3.IBucket;
+    private readonly keyGlob: string;
+    private readonly uri: string;
+
+    constructor(opts: { bucket?: s3.IBucket, keyPrefix?: string, uri: string }) {
+        super();
+        this.bucket = opts.bucket;
+        this.keyGlob = `${opts.keyPrefix || ''}*`;
+        this.uri = opts.uri;
+    }
+
+    public bind(task: ISageMakerTask, opts: S3LocationBindOptions): S3LocationConfig {
+        if (this.bucket) {
+            if (opts.forReading) {
+                this.bucket.grantRead(task, this.keyGlob);
+            }
+            if (opts.forWriting) {
+                this.bucket.grantWrite(task, this.keyGlob);
+            }
+        } else {
+            const actions = new Array<string>();
+            if (opts.forReading) {
+                actions.push('s3:GetObject', 's3:ListBucket');
+            }
+            if (opts.forWriting) {
+                actions.push('s3:PutObject');
+            }
+            task.grantPrincipal.addToPolicy(new iam.PolicyStatement({ actions, resources: ['*'], }));
+        }
+        return { uri: this.uri };
+    }
+}