feat: allow to use an existing sharp layer via arn (#96)

* feat: allow to re-use the sharp layer

* feat: allow to re-use the sharp layer

* fix: rerun build command

README.md

@@ -131,6 +131,16 @@ class NextjsSst extends Nextjs {
 }
 ```
 
+## Contribute
+
+Hey there, we value every new contribution a lot 🙏🏼 thank you.
+
+Here is a short HowTo before you get started:
+
+1. Please make sure to create a bug first
+2. Link the bug in your pull request
+3. Run `yarn build` after you made your changes and before you open a pull request
+
 ## Breaking changes
 
 - v2.0.0: SST wrapper changed, lambda/assets/distribution defaults now are in the `defaults` prop, refactored distribution settings into the new NextjsDistribution construct. If you are upgrading, you must temporarily remove the `customDomain` on your existing 1.x.x app before upgrading to >=2.x.x because the CloudFront distribution will get recreated due to refactoring, and the custom domain must be globally unique across all CloudFront distributions. Prepare for downtime.

src/ImageOptimizationLambda.ts

@@ -2,14 +2,13 @@ import * as fs from 'fs';
 import * as path from 'path';
 import { Duration } from 'aws-cdk-lib';
 import { Policy, PolicyStatement } from 'aws-cdk-lib/aws-iam';
-import { FunctionOptions } from 'aws-cdk-lib/aws-lambda';
+import { FunctionOptions, ILayerVersion } from 'aws-cdk-lib/aws-lambda';
 import { NodejsFunction } from 'aws-cdk-lib/aws-lambda-nodejs';
 import { IBucket } from 'aws-cdk-lib/aws-s3';
 import { Construct } from 'constructs';
 import { LAMBDA_RUNTIME } from './constants';
 import { NextjsBaseProps } from './NextjsBase';
 import type { NextjsBuild } from './NextjsBuild';
-import { NextjsLayer } from './NextjsLayer';
 // import { config } from 'process';
 
 export type RemotePattern = {
@@ -33,7 +32,7 @@ export interface ImageOptimizationProps extends NextjsBaseProps {
   /**
    * NextjsLayer - sharp runtime
    */
-  readonly nextLayer: NextjsLayer;
+  readonly nextLayer: ILayerVersion;
   /**
    * The `NextjsBuild` instance representing the built Nextjs application.
    */

src/Nextjs.ts

@@ -2,7 +2,7 @@ import * as os from 'os';
 import * as path from 'path';
 import { RemovalPolicy } from 'aws-cdk-lib';
 import * as lambda from 'aws-cdk-lib/aws-lambda';
-import { FunctionOptions } from 'aws-cdk-lib/aws-lambda';
+import { FunctionOptions, LayerVersion } from 'aws-cdk-lib/aws-lambda';
 import * as s3 from 'aws-cdk-lib/aws-s3';
 import { Construct } from 'constructs';
 import * as fs from 'fs-extra';
@@ -128,7 +128,9 @@ export class Nextjs extends Construct {
       });
 
     // layer
-    const nextLayer = new NextjsLayer(scope, 'NextjsLayer', {});
+    const nextLayer = props.sharpLayerArn?.length
+      ? LayerVersion.fromLayerVersionArn(scope, 'NextjsLayer', props.sharpLayerArn)
+      : new NextjsLayer(scope, 'NextjsLayer', {});
 
     // build nextjs app
     this.nextBuild = new NextjsBuild(this, id, { ...props, tempBuildDir });

src/NextjsBase.ts

@@ -66,6 +66,12 @@ export interface NextjsBaseProps {
    * Less build output.
    */
   readonly quiet?: boolean;
+
+  /**
+   * Optional arn for the sharp lambda layer.
+   * If omitted, the layer will be created.
+   */
+  readonly sharpLayerArn?: string;
 }
 
 ///// stuff below taken from https://github.com/serverless-stack/sst/blob/8d377e941467ced81d8cc31ee67d5a06550f04d4/packages/resources/src/BaseSite.ts