Infer the ARN from the parts of the invoked lambda function arn

Author: rogperez

packages/cdk-blue-green-container-deployment/src/__tests__/lambdas/__fixtures__/defaultContext.ts

@@ -2,7 +2,7 @@ export const defaultContext = {
   callbackWaitsForEmptyEventLoop: true,
   functionName: 'foo',
   functionVersion: 'foo',
-  invokedFunctionArn: 'foo',
+  invokedFunctionArn: 'arn:aws:lambda:eu-west-1:012345678910:function:MyCustomResourceHandler',
   memoryLimitInMB: 'foo',
   awsRequestId: 'foo',
   logGroupName: 'foo',

packages/cdk-blue-green-container-deployment/src/__tests__/lambdas/ecs-deployment-group/index.test.ts

@@ -40,8 +40,8 @@ import { defaultEvent } from '../__fixtures__/defaultEvent';
 import { defaultLogger } from '../__fixtures__/defaultLogger';
 
 const defaultEcsDeploymentGroupProperties = {
-  ApplicationName: 'Foo',
-  DeploymentGroupName: 'Foo',
+  ApplicationName: 'TestApplicationName',
+  DeploymentGroupName: 'TestDeploymentGroupName',
   ServiceRoleArn: 'arn:aws:iam::012345678910:role/MyRole',
   EcsServices: [
     {
@@ -52,8 +52,7 @@ const defaultEcsDeploymentGroupProperties = {
   TargetGroupNames: ['Foo'],
   ProdTrafficListenerArn: 'arn:aws:elasticloadbalancing::012345678910:listener/app/MyApp/foo/prod',
   TestTrafficListenerArn: 'arn:aws:elasticloadbalancing::012345678910:listener/app/MyApp/foo/test',
-  TerminationWaitTimeInMinutes: 5,
-  ArnForDeploymentGroup: 'arn:aws:ecs:us-east-1:012345678910:service/MyCluster/MyService',
+  TerminationWaitTimeInMinutes: 5
 };
 
 describe('createHandler', () => {
@@ -84,10 +83,41 @@ describe('createHandler', () => {
       }),
     );
   });
+
+  it('returns the physical id and arn of the deployment group', async () => {
+    const response = await handleCreate(
+      {
+        ...defaultEvent,
+        RequestType: 'Create',
+        ResourceProperties: {
+          ServiceToken: 'foo',
+          ...defaultEcsDeploymentGroupProperties,
+          Tags: [
+            { Key: 'foo', Value: 'bar' },
+            { Key: 'k', Value: 'west' },
+          ],
+        },
+      },
+      {
+        ...defaultContext,
+        invokedFunctionArn: 'arn:aws:lambda:eu-west-1:012345678910:function:MyCustomResourceHandler'
+      },
+      defaultLogger,
+    );
+
+    expect(response).toEqual(
+      expect.objectContaining({
+        physicalResourceId: 'TestDeploymentGroupName',
+        responseData: {
+          Arn: 'arn:aws:codedeploy:eu-west-1:012345678910:deploymentgroup:TestApplicationName/TestDeploymentGroupName'
+        },
+      }),
+    );
+  })
 });
 
 describe('updateHandler', () => {
-  it('sends data update request', async () => {
+  it('sends data update requests', async () => {
     await handleUpdate(
       {
         ...defaultEvent,
@@ -119,13 +149,13 @@ describe('updateHandler', () => {
     expect(mockUpdateRequest).toHaveBeenCalled();
 
     expect(mockUntagResourceRequest).toHaveBeenCalledWith({
-      ResourceArn: 'arn:aws:ecs:us-east-1:012345678910:service/MyCluster/MyService',
+      ResourceArn: 'arn:aws:codedeploy:eu-west-1:012345678910:deploymentgroup:TestApplicationName/TestDeploymentGroupName',
       TagKeys: ['foo'],
     });
 
     expect(mockTagResourceRequest).toHaveBeenCalledWith(
       expect.objectContaining({
-        ResourceArn: 'arn:aws:ecs:us-east-1:012345678910:service/MyCluster/MyService',
+        ResourceArn: 'arn:aws:codedeploy:eu-west-1:012345678910:deploymentgroup:TestApplicationName/TestDeploymentGroupName',
         Tags: [
           { Key: 'dis', Value: 'dat' },
           { Key: 'k', Value: 'west' },
@@ -134,4 +164,35 @@ describe('updateHandler', () => {
       }),
     );
   });
+
+  it('returns the physical id and arn of the deployment group', async () => {
+    const response = await handleUpdate(
+      {
+        ...defaultEvent,
+        RequestType: 'Update',
+        PhysicalResourceId: 'foo',
+        ResourceProperties: {
+          ...defaultEcsDeploymentGroupProperties,
+          ServiceToken: 'foo',
+        },
+        OldResourceProperties: {
+          ...defaultEcsDeploymentGroupProperties,
+        },
+      },
+      {
+        ...defaultContext,
+        invokedFunctionArn: 'arn:aws:lambda:us-east-1:012345678910:function:MyCustomResourceHandler',
+      },
+      defaultLogger,
+    );
+
+    expect(response).toEqual(
+      expect.objectContaining({
+        physicalResourceId: 'TestDeploymentGroupName',
+        responseData: {
+          Arn: 'arn:aws:codedeploy:us-east-1:012345678910:deploymentgroup:TestApplicationName/TestDeploymentGroupName'
+        },
+      }),
+    );
+  })
 });

packages/cdk-blue-green-container-deployment/src/ecs-deployment-group.ts

@@ -146,10 +146,7 @@ export class EcsDeploymentGroup extends Resource implements IEcsDeploymentGroup,
     }
     this.node.addDependency(...ecsServices);
 
-    this.deploymentGroupName = deploymentGroupName;
-    this.deploymentGroupArn = this.arnForDeploymentGroup(this.application.applicationName, deploymentGroupName);
-
-    new CustomResource(this, 'CustomResource', {
+    const ecsDeploymentGroup = new CustomResource(this, 'CustomResource', {
       serviceToken: serviceToken.functionArn,
       resourceType: 'Custom::EcsDeploymentGroup',
       properties: {
@@ -167,13 +164,11 @@ export class EcsDeploymentGroup extends Resource implements IEcsDeploymentGroup,
         AutoRollbackOnEvents: autoRollbackOnEvents,
         DeploymentConfigName: this.deploymentConfig.deploymentConfigName,
         Tags: Lazy.any({ produce: () => this.tags.renderTags() }),
-        ArnForDeploymentGroup: this.arnForDeploymentGroup(this.application.applicationName, deploymentGroupName),
       },
     });
-  }
 
-  private arnForDeploymentGroup(applicationName: string, deploymentGroupName: string): string {
-    return `arn:${Aws.PARTITION}:codedeploy:${Aws.REGION}:${Aws.ACCOUNT_ID}:deploymentgroup:${applicationName}/${deploymentGroupName}`;
+    this.deploymentGroupName = ecsDeploymentGroup.ref;
+    this.deploymentGroupArn = ecsDeploymentGroup.getAttString('Arn');
   }
 }
 

packages/cdk-blue-green-container-deployment/src/lambdas/ecs-deployment-group/index.ts

@@ -24,12 +24,17 @@ export interface EcsDeploymentGroupProps {
   prodTrafficListenerArn: string;
   testTrafficListenerArn: string;
   terminationWaitTimeInMinutes: number;
-  arnForDeploymentGroup: string;
   tags: CodeDeploy.Tag[];
   autoRollbackOnEvents?: RollbackEvent[];
   deploymentConfigName?: string;
 }
 
+interface ArnParts {
+  awsPartition: string;
+  awsRegion: string;
+  awsAccountId: string;
+}
+
 const codeDeploy = new CodeDeploy();
 
 const getProperties = (
@@ -48,11 +53,10 @@ const getProperties = (
   terminationWaitTimeInMinutes: props.TerminationWaitTimeInMinutes,
   autoRollbackOnEvents: props.AutoRollbackOnEvents,
   deploymentConfigName: props.DeploymentConfigName,
-  arnForDeploymentGroup: props.ArnForDeploymentGroup,
   tags: props.Tags ?? [],
 });
 
-export const handleCreate: OnCreateHandler = async (event): Promise<ResourceHandlerReturn> => {
+export const handleCreate: OnCreateHandler = async (event, context): Promise<ResourceHandlerReturn> => {
   const {
     applicationName,
     deploymentGroupName,
@@ -112,12 +116,16 @@ export const handleCreate: OnCreateHandler = async (event): Promise<ResourceHand
 
   return {
     physicalResourceId: deploymentGroupName,
+    responseData: {
+      Arn: arnForDeploymentGroup(applicationName, deploymentGroupName, extractArnParts(context.invokedFunctionArn))
+    },
   };
 };
 
-export const handleUpdate: OnUpdateHandler = async (event): Promise<ResourceHandlerReturn> => {
+export const handleUpdate: OnUpdateHandler = async (event, context): Promise<ResourceHandlerReturn> => {
   const newProps = getProperties(event.ResourceProperties);
   const oldProps = getProperties(event.OldResourceProperties);
+  const deploymentGroupArn = arnForDeploymentGroup(newProps.applicationName, newProps.deploymentGroupName, extractArnParts(context.invokedFunctionArn));
 
   await codeDeploy
     .updateDeploymentGroup({
@@ -163,7 +171,7 @@ export const handleUpdate: OnUpdateHandler = async (event): Promise<ResourceHand
   if (removableTagKeys.length > 0) {
     await codeDeploy
       .untagResource({
-        ResourceArn: newProps.arnForDeploymentGroup,
+        ResourceArn: deploymentGroupArn,
         TagKeys: removableTagKeys,
       })
       .promise();
@@ -172,14 +180,17 @@ export const handleUpdate: OnUpdateHandler = async (event): Promise<ResourceHand
   if (newProps.tags.length > 0) {
     await codeDeploy
       .tagResource({
-        ResourceArn: newProps.arnForDeploymentGroup,
+        ResourceArn: deploymentGroupArn,
         Tags: newProps.tags,
       })
       .promise();
   }
 
   return {
     physicalResourceId: newProps.deploymentGroupName,
+    responseData: {
+      Arn: deploymentGroupArn
+    },
   };
 };
 
@@ -194,6 +205,22 @@ const handleDelete: OnDeleteHandler = async (event): Promise<void> => {
     .promise();
 };
 
+const extractArnParts = (invokedFunctionArn: string): ArnParts => {
+  const matcher = invokedFunctionArn.match(/arn:(?<partition>\w+):lambda:(?<region>[\w\-]+):(?<accountId>\d+):.*/);
+  if(!matcher || !matcher.groups || !matcher.groups.partition || !matcher.groups.region || !matcher.groups.accountId) {
+    throw new Error(`Unable to extract necessary parts from function name. (${invokedFunctionArn}).`)
+  }
+  return {
+    awsPartition: matcher.groups.partition,
+    awsRegion: matcher.groups.region,
+    awsAccountId: matcher.groups.accountId
+  }
+}
+
+const arnForDeploymentGroup = (applicationName: string, deploymentGroupName: string, arnParts: ArnParts): string => {
+  return `arn:${arnParts.awsPartition}:codedeploy:${arnParts.awsRegion}:${arnParts.awsAccountId}:deploymentgroup:${applicationName}/${deploymentGroupName}`
+}
+
 export const handler = customResourceHelper(
   (): ResourceHandler => ({
     onCreate: handleCreate,