feat(pipes-targets): Add step function target

Co-authored-by: RaphaelManke <RaphaelManke@users.noreply.github.com>

packages/@aws-cdk/aws-pipes-targets-alpha/README.md

@@ -27,6 +27,11 @@ For more details see the service documentation:
 
 Pipe targets are the end point of a EventBridge Pipe.
 
+The following targets are supported:
+
+1. `targets.SqsTarget`: [Send event source to a Queue](#amazon-sqs)
+2. `targets.StepFunctionTarget`: [Start a Step function from an event source](#aws-step-function)
+
 ### Amazon SQS
 
 A SQS message queue can be used as a target for a pipe. Messages will be pushed to the queue.
@@ -43,7 +48,7 @@ const pipe = new pipes.Pipe(this, 'Pipe', {
 });
 ```
 
-The target configuration can be transformed:
+The target input can be transformed:
 
 ```ts
 declare const sourceQueue: sqs.Queue;
@@ -63,3 +68,42 @@ const pipe = new pipes.Pipe(this, 'Pipe', {
     target: pipeTarget
 });
 ```
+
+### AWS Step Function
+
+A Step Function can be used as a target for a pipe. Step Functions will be invoked with the (enriched/filtered) source payload.
+
+```ts
+declare const sourceQueue: sqs.Queue;
+declare const targetStateMachine: sfn.IStateMachine;
+
+const pipeTarget = new targets.StepFunctionTarget(targetStateMachine,
+    {
+      invocationType: targets.StepFunctionInvocationType.FIRE_AND_FORGET,
+    }
+);
+
+const pipe = new pipes.Pipe(this, 'Pipe', {
+    source: new SomeSource(sourceQueue),
+    target: pipeTarget
+});
+```
+
+The target input can be transformed:
+
+```ts
+declare const sourceQueue: sqs.Queue;
+declare const targetStateMachine: sfn.IStateMachine;
+
+const pipeTarget = new targets.StepFunctionTarget(targetStateMachine,
+    {
+      inputTransformation: pipes.InputTransformation.fromObject({ body: '<$.body>' }),
+      invocationType: targets.StepFunctionInvocationType.FIRE_AND_FORGET,
+    }
+);
+
+const pipe = new pipes.Pipe(this, 'Pipe', {
+    source: new SomeSource(sourceQueue),
+    target: pipeTarget
+});
+```

packages/@aws-cdk/aws-pipes-targets-alpha/lib/index.ts

@@ -1 +1,2 @@
 export * from './sqs';
+export * from './step-function';

packages/@aws-cdk/aws-pipes-targets-alpha/lib/step-function.ts

@@ -0,0 +1,83 @@
+import { IInputTransformation, IPipe, ITarget, TargetConfig } from '@aws-cdk/aws-pipes-alpha';
+import { IRole } from 'aws-cdk-lib/aws-iam';
+import * as sfn from 'aws-cdk-lib/aws-stepfunctions';
+import { StateMachine, StateMachineType } from 'aws-cdk-lib/aws-stepfunctions';
+
+/**
+ * StateMachine StepFunction target properties.
+ */
+export interface StateMachineTargetParameters {
+  /**
+   * The input transformation to apply to the message before sending it to the target.
+   *
+   * @see https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-pipes-pipe-pipetargetparameters.html#cfn-pipes-pipe-pipetargetparameters-inputtemplate
+   * @default none
+   */
+  readonly inputTransformation?: IInputTransformation;
+
+  /**
+   * Specify whether to invoke the Step Functions state machine synchronously (`REQUEST_RESPONSE`) or asynchronously (`FIRE_AND_FORGET`).
+   *
+   * @see http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-pipes-pipe-pipetargetsqsqueueparameters.html#cfn-pipes-pipe-pipetargetsqsqueueparameters-messagededuplicationid
+   */
+  readonly invocationType: StepFunctionInvocationType;
+}
+
+/**
+ * InvocationType for invoking StepFunction.
+ * @see https://docs.aws.amazon.com/eventbridge/latest/pipes-reference/API_PipeTargetStateMachineParameters.html
+ */
+export enum StepFunctionInvocationType {
+  /**
+   * Invoke StepFunction asynchronously (`StartExecution`). See https://docs.aws.amazon.com/step-functions/latest/apireference/API_StartExecution.html for more details.
+   */
+  FIRE_AND_FORGET = 'FIRE_AND_FORGET',
+
+  /**
+   * Invoke StepFunction synchronously (`StartSyncExecution`) and wait for the execution to complete. See https://docs.aws.amazon.com/step-functions/latest/apireference/API_StartSyncExecution.html for more details.
+   */
+  REQUEST_RESPONSE = 'REQUEST_RESPONSE',
+}
+
+/**
+ * An EventBridge Pipes target that sends messages to a StepFunction.
+ */
+export class StepFunctionTarget implements ITarget {
+  public readonly targetArn: string;
+
+  private readonly stateMachine: sfn.IStateMachine;
+  private readonly invocationType: StepFunctionInvocationType;
+  private readonly inputTemplate?: IInputTransformation;
+
+  constructor(stateMachine: sfn.IStateMachine, parameters: StateMachineTargetParameters) {
+    this.stateMachine = stateMachine;
+    this.targetArn = stateMachine.stateMachineArn;
+    this.invocationType = parameters.invocationType;
+    this.inputTemplate = parameters.inputTransformation;
+
+    if (this.stateMachine instanceof StateMachine
+      && this.stateMachine.stateMachineType === StateMachineType.STANDARD
+      && this.invocationType === StepFunctionInvocationType.REQUEST_RESPONSE) {
+      throw new Error('Standard Workflows do not support REQUEST_RESPONSE invocation type');
+    }
+  }
+
+  grantPush(grantee: IRole): void {
+    if (this.invocationType === StepFunctionInvocationType.FIRE_AND_FORGET) {
+      this.stateMachine.grantStartExecution(grantee);
+    } else {
+      this.stateMachine.grantStartSyncExecution(grantee);
+    }
+  }
+
+  bind(pipe: IPipe): TargetConfig {
+    return {
+      targetParameters: {
+        inputTemplate: this.inputTemplate?.bind(pipe).inputTemplate,
+        stepFunctionStateMachineParameters: {
+          invocationType: this.invocationType,
+        },
+      },
+    };
+  }
+}

packages/@aws-cdk/aws-pipes-targets-alpha/rosetta/default.ts-fixture

@@ -1,6 +1,7 @@
 // Fixture with packages imported, but nothing else
 import * as cdk from 'aws-cdk-lib';
 import * as sqs from 'aws-cdk-lib/aws-sqs';
+import * as sfn from 'aws-cdk-lib/aws-stepfunctions';
 import { Construct } from 'constructs';
 import * as pipes from '@aws-cdk/aws-pipes-alpha';
 import * as targets from '@aws-cdk/aws-pipes-targets-alpha';

packages/@aws-cdk/aws-pipes-targets-alpha/test/__snapshots__/step-function.test.ts.snap

@@ -0,0 +1,95 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`step-function should grant pipe role push access (StartAsyncExecution) with invocation type FIRE_AND_FORGET 1`] = `
+{
+  "MySfnPipeRoleF1D0F697": {
+    "Properties": {
+      "AssumeRolePolicyDocument": {
+        "Statement": [
+          {
+            "Action": "sts:AssumeRole",
+            "Effect": "Allow",
+            "Principal": {
+              "Service": "pipes.amazonaws.com",
+            },
+          },
+        ],
+        "Version": "2012-10-17",
+      },
+    },
+    "Type": "AWS::IAM::Role",
+  },
+  "MyStateMachineRoleD59FFEBC": {
+    "Properties": {
+      "AssumeRolePolicyDocument": {
+        "Statement": [
+          {
+            "Action": "sts:AssumeRole",
+            "Effect": "Allow",
+            "Principal": {
+              "Service": {
+                "Fn::FindInMap": [
+                  "ServiceprincipalMap",
+                  {
+                    "Ref": "AWS::Region",
+                  },
+                  "states",
+                ],
+              },
+            },
+          },
+        ],
+        "Version": "2012-10-17",
+      },
+    },
+    "Type": "AWS::IAM::Role",
+  },
+}
+`;
+
+exports[`step-function should grant pipe role push access (StartSyncExecution) with invocation type REQUEST-RESPONSE 1`] = `
+{
+  "MySfnPipeRoleF1D0F697": {
+    "Properties": {
+      "AssumeRolePolicyDocument": {
+        "Statement": [
+          {
+            "Action": "sts:AssumeRole",
+            "Effect": "Allow",
+            "Principal": {
+              "Service": "pipes.amazonaws.com",
+            },
+          },
+        ],
+        "Version": "2012-10-17",
+      },
+    },
+    "Type": "AWS::IAM::Role",
+  },
+  "MyStateMachineRoleD59FFEBC": {
+    "Properties": {
+      "AssumeRolePolicyDocument": {
+        "Statement": [
+          {
+            "Action": "sts:AssumeRole",
+            "Effect": "Allow",
+            "Principal": {
+              "Service": {
+                "Fn::FindInMap": [
+                  "ServiceprincipalMap",
+                  {
+                    "Ref": "AWS::Region",
+                  },
+                  "states",
+                ],
+              },
+            },
+          },
+        ],
+        "Version": "2012-10-17",
+      },
+    },
+    "Type": "AWS::IAM::Role",
+  },
+}
+`;