fix(lambda): SAM CLI asset metadata missing from image Functions

packages/@aws-cdk/aws-ecr-assets/lib/image-asset.ts

@@ -1,7 +1,7 @@
 import * as fs from 'fs';
 import * as path from 'path';
 import * as ecr from '@aws-cdk/aws-ecr';
-import { Annotations, AssetStaging, FeatureFlags, FileFingerprintOptions, IgnoreMode, Stack, SymlinkFollowMode, Token, Stage } from '@aws-cdk/core';
+import { Annotations, AssetStaging, FeatureFlags, FileFingerprintOptions, IgnoreMode, Stack, SymlinkFollowMode, Token, Stage, CfnResource } from '@aws-cdk/core';
 import * as cxapi from '@aws-cdk/cx-api';
 import { Construct } from 'constructs';
 
@@ -147,6 +147,29 @@ export class DockerImageAsset extends CoreConstruct implements IAsset {
    */
   public readonly assetHash: string;
 
+  /**
+   * The path to the asset, relative to the current Cloud Assembly
+   *
+   * If asset staging is disabled, this will just be the original path.
+   * If asset staging is enabled it will be the staged path.
+   */
+  private readonly assetPath: string;
+
+  /**
+   * The path to the Dockerfile, relative to the assetPath
+   */
+  private readonly dockerfilePath?: string;
+
+  /**
+   * Build args to pass to the `docker build` command.
+   */
+  private readonly dockerBuildArgs?: { [key: string]: string };
+
+  /**
+   * Docker target to build to
+   */
+  private readonly dockerBuildTarget?: string;
+
   constructor(scope: Construct, id: string, props: DockerImageAssetProps) {
     super(scope, id);
 
@@ -160,7 +183,8 @@ export class DockerImageAsset extends CoreConstruct implements IAsset {
     }
 
     // validate the docker file exists
-    const file = path.join(dir, props.file || 'Dockerfile');
+    this.dockerfilePath = props.file || 'Dockerfile';
+    const file = path.join(dir, this.dockerfilePath);
     if (!fs.existsSync(file)) {
       throw new Error(`Cannot find file at ${file}`);
     }
@@ -223,17 +247,53 @@ export class DockerImageAsset extends CoreConstruct implements IAsset {
     this.assetHash = staging.assetHash;
 
     const stack = Stack.of(this);
+    this.assetPath = staging.relativeStagedPath(stack);
+    this.dockerBuildArgs = props.buildArgs;
+    this.dockerBuildTarget = props.target;
+
     const location = stack.synthesizer.addDockerImageAsset({
-      directoryName: staging.relativeStagedPath(stack),
-      dockerBuildArgs: props.buildArgs,
-      dockerBuildTarget: props.target,
+      directoryName: this.assetPath,
+      dockerBuildArgs: this.dockerBuildArgs,
+      dockerBuildTarget: this.dockerBuildTarget,
       dockerFile: props.file,
       sourceHash: staging.assetHash,
     });
 
     this.repository = ecr.Repository.fromRepositoryName(this, 'Repository', location.repositoryName);
     this.imageUri = location.imageUri;
   }
+
+  /**
+   * Adds CloudFormation template metadata to the specified resource with
+   * information that indicates which resource property is mapped to this local
+   * asset. This can be used by tools such as SAM CLI to provide local
+   * experience such as local invocation and debugging of Lambda functions.
+   *
+   * Asset metadata will only be included if the stack is synthesized with the
+   * "aws:cdk:enable-asset-metadata" context key defined, which is the default
+   * behavior when synthesizing via the CDK Toolkit.
+   *
+   * @see https://github.com/aws/aws-cdk/issues/1432
+   *
+   * @param resource The CloudFormation resource which is using this asset [disable-awslint:ref-via-interface]
+   * @param resourceProperty The property name where this asset is referenced
+   */
+  public addResourceMetadata(resource: CfnResource, resourceProperty: string) {
+    if (!this.node.tryGetContext(cxapi.ASSET_RESOURCE_METADATA_ENABLED_CONTEXT)) {
+      return; // not enabled
+    }
+
+    // tell tools such as SAM CLI that the resourceProperty of this resource
+    // points to a local path and include the path to de dockerfile, docker build args, and target,
+    // in order to enable local invocation of this function.
+    resource.cfnOptions.metadata = resource.cfnOptions.metadata || { };
+    resource.cfnOptions.metadata[cxapi.ASSET_RESOURCE_METADATA_PATH_KEY] = this.assetPath;
+    resource.cfnOptions.metadata[cxapi.ASSET_RESOURCE_METADATA_DOCKERFILE_PATH_KEY] = this.dockerfilePath;
+    resource.cfnOptions.metadata[cxapi.ASSET_RESOURCE_METADATA_DOCKER_BUILD_ARGS_KEY] = this.dockerBuildArgs;
+    resource.cfnOptions.metadata[cxapi.ASSET_RESOURCE_METADATA_DOCKER_BUILD_TARGET_KEY] = this.dockerBuildTarget;
+    resource.cfnOptions.metadata[cxapi.ASSET_RESOURCE_METADATA_PROPERTY_KEY] = resourceProperty;
+  }
+
 }
 
 function validateProps(props: DockerImageAssetProps) {

packages/@aws-cdk/aws-lambda/lib/code.ts

@@ -517,28 +517,45 @@ export interface AssetImageCodeProps extends ecr_assets.DockerImageAssetOptions
  */
 export class AssetImageCode extends Code {
   public readonly isInline: boolean = false;
+  private asset?: ecr_assets.DockerImageAsset;
 
   constructor(private readonly directory: string, private readonly props: AssetImageCodeProps) {
     super();
   }
 
   public bind(scope: Construct): CodeConfig {
-    const asset = new ecr_assets.DockerImageAsset(scope, 'AssetImage', {
-      directory: this.directory,
-      ...this.props,
-    });
-
-    asset.repository.grantPull(new iam.ServicePrincipal('lambda.amazonaws.com'));
+    // If the same AssetImageCode is used multiple times, retain only the first instantiation.
+    if (!this.asset) {
+      this.asset = new ecr_assets.DockerImageAsset(scope, 'AssetImage', {
+        directory: this.directory,
+        ...this.props,
+      });
+      this.asset.repository.grantPull(new iam.ServicePrincipal('lambda.amazonaws.com'));
+    } else if (cdk.Stack.of(this.asset) !== cdk.Stack.of(scope)) {
+      throw new Error(`Asset is already associated with another stack '${cdk.Stack.of(this.asset).stackName}'. ` +
+        'Create a new Code instance for every stack.');
+    }
 
     return {
       image: {
-        imageUri: asset.imageUri,
+        imageUri: this.asset.imageUri,
         entrypoint: this.props.entrypoint,
         cmd: this.props.cmd,
         workingDirectory: this.props.workingDirectory,
       },
     };
   }
+
+  public bindToResource(resource: cdk.CfnResource, options: ResourceBindOptions = { }) {
+    if (!this.asset) {
+      throw new Error('bindToResource() must be called after bind()');
+    }
+
+    const resourceProperty = options.resourceProperty || 'Code.ImageUri';
+
+    // https://github.com/aws/aws-cdk/issues/14593
+    this.asset.addResourceMetadata(resource, resourceProperty);
+  }
 }
 
 /**

packages/@aws-cdk/aws-lambda/test/code.test.ts

@@ -332,6 +332,110 @@ describe('code', () => {
         },
       });
     });
+
+    test('only one Asset object gets created even if multiple functions use the same AssetImageCode', () => {
+      // given
+      const app = new cdk.App();
+      const stack = new cdk.Stack(app, 'MyStack');
+      const directoryAsset = lambda.Code.fromAssetImage(path.join(__dirname, 'docker-lambda-handler'));
+
+      // when
+      new lambda.Function(stack, 'Fn1', {
+        code: directoryAsset,
+        handler: lambda.Handler.FROM_IMAGE,
+        runtime: lambda.Runtime.FROM_IMAGE,
+      });
+
+      new lambda.Function(stack, 'Fn2', {
+        code: directoryAsset,
+        handler: lambda.Handler.FROM_IMAGE,
+        runtime: lambda.Runtime.FROM_IMAGE,
+      });
+
+      // then
+      const assembly = app.synth();
+      const synthesized = assembly.stacks[0];
+
+      // Func1 has an asset, Func2 does not
+      expect(synthesized.assets.length).toEqual(1);
+    });
+
+    test('adds code asset metadata', () => {
+      // given
+      const stack = new cdk.Stack();
+      stack.node.setContext(cxapi.ASSET_RESOURCE_METADATA_ENABLED_CONTEXT, true);
+
+      const dockerfilePath = 'Dockerfile';
+      const dockerBuildTarget = 'stage';
+      const dockerBuildArgs = { arg1: 'val1', arg2: 'val2' };
+
+      // when
+      new lambda.Function(stack, 'Fn', {
+        code: lambda.Code.fromAssetImage(path.join(__dirname, 'docker-lambda-handler'), {
+          file: dockerfilePath,
+          target: dockerBuildTarget,
+          buildArgs: dockerBuildArgs,
+        }),
+        handler: lambda.Handler.FROM_IMAGE,
+        runtime: lambda.Runtime.FROM_IMAGE,
+      });
+
+      // then
+      expect(stack).toHaveResource('AWS::Lambda::Function', {
+        Metadata: {
+          [cxapi.ASSET_RESOURCE_METADATA_PATH_KEY]: 'asset.650a009a909c30e767a843a84ff7812616447251d245e0ab65d9bfb37f413e32',
+          [cxapi.ASSET_RESOURCE_METADATA_DOCKERFILE_PATH_KEY]: dockerfilePath,
+          [cxapi.ASSET_RESOURCE_METADATA_DOCKER_BUILD_ARGS_KEY]: dockerBuildArgs,
+          [cxapi.ASSET_RESOURCE_METADATA_DOCKER_BUILD_TARGET_KEY]: dockerBuildTarget,
+          [cxapi.ASSET_RESOURCE_METADATA_PROPERTY_KEY]: 'Code.ImageUri',
+        },
+      }, ResourcePart.CompleteDefinition);
+    });
+
+    test('adds code asset metadata with default dockerfile path', () => {
+      // given
+      const stack = new cdk.Stack();
+      stack.node.setContext(cxapi.ASSET_RESOURCE_METADATA_ENABLED_CONTEXT, true);
+
+      // when
+      new lambda.Function(stack, 'Fn', {
+        code: lambda.Code.fromAssetImage(path.join(__dirname, 'docker-lambda-handler')),
+        handler: lambda.Handler.FROM_IMAGE,
+        runtime: lambda.Runtime.FROM_IMAGE,
+      });
+
+      // then
+      expect(stack).toHaveResource('AWS::Lambda::Function', {
+        Metadata: {
+          [cxapi.ASSET_RESOURCE_METADATA_PATH_KEY]: 'asset.a3cc4528c34874616814d9b3436ff0e5d01514c1d563ed8899657ca00982f308',
+          [cxapi.ASSET_RESOURCE_METADATA_DOCKERFILE_PATH_KEY]: 'Dockerfile',
+          [cxapi.ASSET_RESOURCE_METADATA_PROPERTY_KEY]: 'Code.ImageUri',
+        },
+      }, ResourcePart.CompleteDefinition);
+    });
+
+    test('fails if asset is bound with a second stack', () => {
+      // given
+      const app = new cdk.App();
+      const asset = lambda.Code.fromAssetImage(path.join(__dirname, 'docker-lambda-handler'));
+
+      // when
+      const stack1 = new cdk.Stack(app, 'Stack1');
+      new lambda.Function(stack1, 'Fn', {
+        code: asset,
+        handler: lambda.Handler.FROM_IMAGE,
+        runtime: lambda.Runtime.FROM_IMAGE,
+      });
+
+      const stack2 = new cdk.Stack(app, 'Stack2');
+
+      // then
+      expect(() => new lambda.Function(stack2, 'Fn', {
+        code: asset,
+        handler: lambda.Handler.FROM_IMAGE,
+        runtime: lambda.Runtime.FROM_IMAGE,
+      })).toThrow(/already associated/);
+    });
   });
 
   describe('lambda.Code.fromDockerBuild', () => {

packages/@aws-cdk/cx-api/lib/assets.ts

@@ -10,6 +10,9 @@ export const ASSET_RESOURCE_METADATA_ENABLED_CONTEXT = 'aws:cdk:enable-asset-met
  * to resources.
  */
 export const ASSET_RESOURCE_METADATA_PATH_KEY = 'aws:asset:path';
+export const ASSET_RESOURCE_METADATA_DOCKERFILE_PATH_KEY = 'aws:asset:dockerfile-path';
+export const ASSET_RESOURCE_METADATA_DOCKER_BUILD_ARGS_KEY = 'aws:asset:docker-build-args';
+export const ASSET_RESOURCE_METADATA_DOCKER_BUILD_TARGET_KEY = 'aws:asset:docker-build-target';
 export const ASSET_RESOURCE_METADATA_PROPERTY_KEY = 'aws:asset:property';
 
 /**