feat(new-ex): custom logical names (aws-samples#120)

* custom logical names

an example for how to implement custom logical name allocation.

related: aws/aws-cdk#4045

* Use `ApplicationLoadBalancedFargateService`

README.md

@@ -48,6 +48,7 @@ $ cdk destroy
 | [stepfunctions-job-poller](https://github.com/aws-samples/aws-cdk-examples/tree/master/typescript/stepfunctions-job-poller/) | A simple StepFunctions workflow |
 | [ecs-service-with-logging](https://github.com/aws-samples/aws-cdk-examples/tree/master/typescript/ecs/ecs-service-with-logging/) | Starting a container fronted by a load balancer on ECS |
 | [fargate-service-with-logging](https://github.com/aws-samples/aws-cdk-examples/tree/master/typescript/ecs/fargate-service-with-logging/) | Starting a container fronted by a load balancer on Fargate |
+| [custom-logical-names](https://github.com/aws-samples/aws-cdk-examples/tree/master/typescript/custom-logical-names/) | Example of how to override logical name allocation |
 
 ## Java examples <a name="Java"></a>
 

typescript/custom-logical-names/README.md

@@ -0,0 +1,79 @@
+# Custom Logical Names
+<!--BEGIN STABILITY BANNER-->
+---
+
+![Stability: Stable](https://img.shields.io/badge/stability-Stable-success.svg?style=for-the-badge)
+
+> **This is a stable example. It should successfully build out of the box**
+>
+> This examples does is built on Construct Libraries marked "Stable" and does not have any infrastructure prerequisites to build.
+
+---
+<!--END STABILITY BANNER-->
+
+This sample shows how you can override the behavior for allocating
+logical names for CloudFormation resources in the CDK.
+
+It implements a feature that allows users to specify a prefix for
+all logical names using the `prefix` context key.
+
+## Usage
+
+1. Extend your stacks from `BaseStack` instead of from `Stack`.
+2. Specify context when calling the CLI through `--context prefix=PREFIX`.
+
+## Implementation
+
+The `BaseStack` class implements this custom behavior. Using a base stack is a a
+common and recommended pattern for reusing policy within an organization.
+
+Then, any stack that derives from `BaseStack` will automatically have this
+behavior.
+
+## Build
+
+To build this app, you need to be in this example's root folder. Then run the following:
+
+```bash
+npm install -g aws-cdk
+npm install
+npm run build
+```
+
+This will install the necessary CDK, then this example's dependencies, and then build your TypeScript files and your CloudFormation template.
+
+## Deploy
+
+Run `cdk deploy --context prefix=PREFIX`. This will deploy / redeploy your Stack to your AWS Account.
+
+## Example
+
+```shell
+$ cdk synth -j
+{
+  "Resources": {
+    "MyTopic86869434": {
+      "Type": "AWS::SNS::Topic"
+    },
+    "MyBucketF68F3FF0": {
+      "Type": "AWS::S3::Bucket"
+    }
+  }
+}
+```
+
+Now with prefix:
+
+```shell
+$ cdk synth -j -c prefix="MyTeam"
+{
+  "Resources": {
+    "MyTeamMyTopic86869434": {
+      "Type": "AWS::SNS::Topic"
+    },
+    "MyTeamMyBucketF68F3FF0": {
+      "Type": "AWS::S3::Bucket"
+    }
+  }
+}
+```

typescript/custom-logical-names/base-stack.ts

@@ -0,0 +1,16 @@
+import { Stack, CfnElement } from '@aws-cdk/core';
+
+/**
+ * A base stack class that implements custom logical name
+ * allocation. Adds a prefix if it is defined in the "prefix"
+ * context key.
+ *
+ * Use `cdk --context prefix=PREFIX` to set the prefix.
+ */
+export class BaseStack extends Stack {
+  public allocateLogicalId(element: CfnElement) {
+    const orig = super.allocateLogicalId(element);
+    const prefix = this.node.tryGetContext('prefix');
+    return prefix ? prefix + orig : orig;
+  }
+}

typescript/custom-logical-names/cdk.json

@@ -0,0 +1,3 @@
+{
+  "app": "npx ts-node index.ts"
+}

typescript/custom-logical-names/index.ts

@@ -0,0 +1,18 @@
+#!/usr/bin/env node
+import { BaseStack } from './base-stack';
+import { App, Construct, StackProps } from '@aws-cdk/core';
+import s3 = require('@aws-cdk/aws-s3');
+import sns = require('@aws-cdk/aws-sns');
+
+class MyStack extends BaseStack {
+  constructor(scope: Construct, id: string, props?: StackProps) {
+    super(scope, id, props);
+
+    new sns.Topic(this, 'MyTopic');
+    new s3.Bucket(this, 'MyBucket');
+  }
+}
+
+const app = new App();
+new MyStack(app, 'MyStack');
+app.synth();

typescript/custom-logical-names/package.json

@@ -0,0 +1,23 @@
+{
+  "name": "custom-logical-names",
+  "version": "0.1.0",
+  "bin": {
+    "custom-logical-names": "bin/custom-logical-names.js"
+  },
+  "scripts": {
+    "build": "tsc",
+    "watch": "tsc -w",
+    "cdk": "cdk"
+  },
+  "devDependencies": {
+    "aws-cdk": "*",
+    "ts-node": "^8.1.0",
+    "typescript": "~3.7.2"
+  },
+  "dependencies": {
+    "@aws-cdk/aws-s3": "*",
+    "@aws-cdk/aws-sns": "*",
+    "@aws-cdk/core": "*",
+    "source-map-support": "^0.5.9"
+  }
+}

typescript/custom-logical-names/tsconfig.json

@@ -0,0 +1,23 @@
+{
+  "compilerOptions": {
+    "target":"ES2018",
+    "module": "commonjs",
+    "lib": ["es2016", "es2017.object", "es2017.string"],
+    "declaration": true,
+    "strict": true,
+    "noImplicitAny": true,
+    "strictNullChecks": true,
+    "noImplicitThis": true,
+    "alwaysStrict": true,
+    "noUnusedLocals": false,
+    "noUnusedParameters": false,
+    "noImplicitReturns": true,
+    "noFallthroughCasesInSwitch": false,
+    "inlineSourceMap": true,
+    "inlineSources": true,
+    "experimentalDecorators": true,
+    "strictPropertyInitialization":false,
+    "typeRoots": ["./node_modules/@types"]
+  },
+  "exclude": ["cdk.out"]
+}