feat: allowing cloudfront props to be passed in and merging with the defaults (#36)

Author: JakePartusch

packages/construct/package.json

@@ -38,7 +38,8 @@
     "@aws-cdk/aws-route53-targets": "1.95.1",
     "@aws-cdk/aws-s3": "1.95.1",
     "@aws-cdk/aws-s3-deployment": "1.95.1",
-    "@aws-cdk/core": "1.95.1"
+    "@aws-cdk/core": "1.95.1",
+    "deepmerge": "^4.2.2"
   },
   "files": [
     "tsconfig.json",

packages/construct/src/serverless-ui.construct.ts

@@ -12,6 +12,7 @@ import {
   ViewerProtocolPolicy,
   AllowedMethods,
   CachePolicy,
+  DistributionProps,
 } from "@aws-cdk/aws-cloudfront";
 import { IFunction, Runtime } from "@aws-cdk/aws-lambda";
 import { NodejsFunction } from "@aws-cdk/aws-lambda-nodejs";
@@ -22,6 +23,7 @@ import * as path from "path";
 import { HttpOrigin, S3Origin } from "@aws-cdk/aws-cloudfront-origins";
 import { LambdaProxyIntegration } from "@aws-cdk/aws-apigatewayv2-integrations";
 import { HttpApi, IHttpApi } from "@aws-cdk/aws-apigatewayv2";
+import { overrideProps } from "./utils";
 
 interface Domain {
   /**
@@ -68,6 +70,10 @@ interface ServerlessUIProps {
   readonly apiEnvironment?: {
     [key: string]: string;
   };
+  /**
+   * Optional user provided props to merge with the default props for CloudFront Distribution
+   */
+  cloudFrontDistributionProps?: Partial<DistributionProps>;
 }
 
 export class ServerlessUI extends Construct {
@@ -147,10 +153,7 @@ export class ServerlessUI extends Construct {
       },
     };
 
-    /**
-     * Creating a Cloudfront distribution for the website bucket with an aggressive caching policy
-     */
-    const distribution = new Distribution(this, "Distribution", {
+    const defaultDistributionProps = {
       defaultBehavior: {
         origin: new S3Origin(websiteBucket),
         allowedMethods: AllowedMethods.ALLOW_ALL,
@@ -169,7 +172,21 @@ export class ServerlessUI extends Construct {
           ]
         : undefined,
       enableLogging: true,
-    });
+    };
+
+    const mergedDistributionProps = overrideProps(
+      defaultDistributionProps,
+      props.cloudFrontDistributionProps ?? {}
+    );
+
+    /**
+     * Creating a Cloudfront distribution for the website bucket with an aggressive caching policy
+     */
+    const distribution = new Distribution(
+      this,
+      "Distribution",
+      mergedDistributionProps
+    );
 
     new BucketDeployment(this, "BucketDeployment", {
       sources: props.uiSources,

packages/construct/src/utils.ts

@@ -0,0 +1,67 @@
+import deepmerge from "deepmerge";
+
+function isObject(val: object) {
+  return (
+    val != null &&
+    typeof val === "object" &&
+    Object.prototype.toString.call(val) === "[object Object]"
+  );
+}
+
+function isPlainObject(o: object) {
+  if (Array.isArray(o) === true) {
+    return true;
+  }
+
+  if (isObject(o) === false) {
+    return false;
+  }
+
+  // If has modified constructor
+  const ctor = o.constructor;
+  if (typeof ctor !== "function") {
+    return false;
+  }
+
+  // If has modified prototype
+  const prot = ctor.prototype;
+  if (isObject(prot) === false) {
+    return false;
+  }
+
+  // If constructor does not have an Object-specific method
+  if (prot.hasOwnProperty("isPrototypeOf") === false) {
+    return false;
+  }
+
+  // Most likely a plain Object
+  return true;
+}
+
+function combineMerge(target: any[], source: any[]) {
+  return target.concat(source);
+}
+
+function overwriteMerge(target: any[], source: any[]) {
+  target = source;
+  return target;
+}
+
+export function overrideProps(
+  DefaultProps: object,
+  userProps: object,
+  concatArray: boolean = false
+): any {
+  // Override the sensible defaults with user provided props
+  if (concatArray) {
+    return deepmerge(DefaultProps, userProps, {
+      arrayMerge: combineMerge,
+      isMergeableObject: isPlainObject,
+    });
+  } else {
+    return deepmerge(DefaultProps, userProps, {
+      arrayMerge: overwriteMerge,
+      isMergeableObject: isPlainObject,
+    });
+  }
+}

yarn.lock

@@ -3233,6 +3233,11 @@ deep-is@~0.1.3:
   resolved "https://registry.yarnpkg.com/deep-is/-/deep-is-0.1.3.tgz"
   integrity sha1-s2nW+128E+7PUk+RsHD+7cNXzzQ=
 
+deepmerge@^4.2.2:
+  version "4.2.2"
+  resolved "https://registry.yarnpkg.com/deepmerge/-/deepmerge-4.2.2.tgz#44d2ea3679b8f4d4ffba33f03d865fc1e7bf4955"
+  integrity sha512-FJ3UgI4gIl+PHZm53knsuSFpE+nESMr7M4v9QcgB7S63Kj/6WqMiFQJpBBYz1Pt+66bZpP3Q7Lye0Oo9MPKEdg==
+
 defaults@^1.0.3:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/defaults/-/defaults-1.0.3.tgz"