Support building extensions. (#3)

Upload them as layers, and assign them to functions.

Signed-off-by: David Calavera <david.calavera@gmail.com>

Signed-off-by: David Calavera <david.calavera@gmail.com>

Author: calavera

API.md

@@ -5,7 +5,6 @@ This library provides constructs for Rust Lambda functions built with Cargo Lamb
 To use this module you will either need to have [Cargo Lambda installed](https://www.cargo-lambda.info/guide/installation.html) (`0.12.0` or later), or `Docker` installed.
 See [Local Bundling](#local-bundling)/[Docker Bundling](#docker-bundling) for more information.
 
-
 ## Rust Function
 
 Define a `RustFunction`:
@@ -27,10 +26,29 @@ lamda-app
     └── main.rs
 ```
 
-## Runtime
+### Runtime
 
 The `RustFunction` uses the `PROVIDED_AL2` runtime.
 
+## Rust Extension
+
+Define a `RustExtension` that get's deployed as a layer to use it with any other function later.
+
+```ts
+import { RustExtension, RustFunction } from 'cargo-lambda-cdk';
+
+const extensionLayer = new RustExtension(this, 'extension-package-name', {
+  packageDir: 'path/to/package/directory/with/Cargo.toml',
+});
+
+new RustFunction(this, 'function-package-name', {
+  packageDir: 'path/to/package/directory/with/Cargo.toml',
+  layers: [
+    extensionLayer
+  ],
+});
+```
+
 ## Environment
 
 Use the `environment` prop to define additional environment variables when Cargo Lambda runs:
@@ -61,7 +79,7 @@ Use the `bundling.dockerImage` prop to use a custom bundling image:
 ```ts
 import { RustFunction } from 'cargo-lambda-cdk';
 
-new lambda.RustFunction(this, 'package-name', {
+new RustFunction(this, 'package-name', {
   packageDir: 'path/to/package/directory/with/Cargo.toml',
   bundling: {
     dockerImage: DockerImage.fromBuild('/path/to/Dockerfile'),

README.md

@@ -39,6 +39,11 @@ export interface BundlingProps extends BundlingOptions {
    * The name of the binary to build, in case that's different than the package's name.
    */
   readonly binaryName?: string;
+
+  /**
+   * Whether the code to compile is a Lambda Extension or not.
+   */
+  readonly lambdaExtension?: boolean;
 }
 
 interface CommandOptions {
@@ -48,6 +53,7 @@ interface CommandOptions {
   readonly binaryName?: string;
   readonly osPlatform: NodeJS.Platform;
   readonly architecture?: Architecture;
+  readonly lambdaExtension?: boolean;
 }
 
 /**
@@ -103,6 +109,7 @@ export class Bundling implements cdk.BundlingOptions {
       packageName: props.packageName,
       binaryName: props.binaryName,
       architecture: props.architecture,
+      lambdaExtension: props.lambdaExtension,
     });
 
     this.command = ['bash', '-c', bundlingCommand];
@@ -118,6 +125,7 @@ export class Bundling implements cdk.BundlingOptions {
           packageName: props.packageName,
           binaryName: props.binaryName,
           architecture: props.architecture,
+          lambdaExtension: props.lambdaExtension,
         });
       };
 
@@ -162,19 +170,26 @@ export class Bundling implements cdk.BundlingOptions {
       props.outputDir,
     ];
 
+    if (props.lambdaExtension) {
+      buildBinary.push('--extension');
+    }
+
     if (props.architecture) {
       const targetFlag = props.architecture.name == Architecture.ARM_64.name ? '--arm64' : '--x86-64';
       buildBinary.push(targetFlag);
     }
 
+    let flattenPackage = props.packageName;
+
     if (props.binaryName) {
-      buildBinary.push('--flatten');
-      buildBinary.push(props.binaryName);
       buildBinary.push('--bin');
       buildBinary.push(props.binaryName);
-    } else if (props.packageName) {
+      flattenPackage = props.binaryName;
+    }
+
+    if (!props.lambdaExtension && flattenPackage) {
       buildBinary.push('--flatten');
-      buildBinary.push(props.packageName);
+      buildBinary.push(flattenPackage);
     }
 
     return chain([

src/bundling.ts

@@ -0,0 +1,23 @@
+import { existsSync } from 'fs';
+import { join, parse } from 'path';
+
+export function getCargoManifestPath(manifestPath: string): string {
+  // const manifestPathProp = props.manifestPath ?? 'Cargo.toml';
+  const parsedManifestPath = parse(manifestPath);
+  let manifestPathResult: string;
+
+  if (parsedManifestPath.base && parsedManifestPath.ext && parsedManifestPath.base === 'Cargo.toml') {
+    if (!existsSync(manifestPath)) {
+      throw new Error('Cargo.toml doesn\'t exist');
+    }
+    manifestPathResult = manifestPath;
+  } else if (parsedManifestPath.base && parsedManifestPath.ext && parsedManifestPath.base != 'Cargo.toml') {
+    throw new Error('manifestPath is specifying a file that is not Cargo.toml');
+  } else if (!existsSync(join(manifestPath, 'Cargo.toml'))) {
+    throw new Error(`Cargo.toml file at ${manifestPath} doesn't exist`);
+  } else {
+    manifestPathResult = join(manifestPath, 'Cargo.toml');
+  }
+
+  return manifestPathResult;
+}

src/cargo.ts

@@ -0,0 +1,52 @@
+import * as lambda from 'aws-cdk-lib/aws-lambda';
+import { Construct } from 'constructs';
+import { Bundling } from './bundling';
+import { getCargoManifestPath } from './cargo';
+import { BundlingOptions } from './types';
+
+
+export interface RustExtensionProps extends lambda.LayerVersionOptions {
+  /**
+      * The name of the binary to build, in case that's different than the package's name.
+      */
+  readonly binaryName?: string;
+
+  /**
+       * Path to a directory containing your Cargo.toml file, or to your Cargo.toml directly.
+       *
+       * This will accept either a directory path containing a `Cargo.toml` file
+       * or a filepath to your `Cargo.toml` file (i.e. `path/to/Cargo.toml`).
+       *
+       * @default - check the current directory for a `Cargo.toml` file, and throws
+       *  an error if the file doesn't exist.
+       */
+  readonly manifestPath?: string;
+
+  /**
+       * Bundling options
+       *
+       * @default - use default bundling options
+       */
+  readonly bundling?: BundlingOptions;
+}
+
+/**
+ * A Lambda extension written in Rust
+ */
+export class RustExtension extends lambda.LayerVersion {
+  constructor(scope: Construct, packageName: string, props?: RustExtensionProps) {
+    const manifestPath = getCargoManifestPath(props?.manifestPath ?? 'Cargo.toml');
+    const bundling = props?.bundling ?? {};
+
+    super(scope, packageName, {
+      ...props,
+      code: Bundling.bundle({
+        ...bundling,
+        packageName,
+        manifestPath,
+        binaryName: props?.binaryName,
+        lambdaExtension: true,
+      }),
+    });
+  }
+}

src/extension.ts

@@ -1,8 +1,7 @@
-import * as fs from 'fs';
-import * as path from 'path';
 import * as lambda from 'aws-cdk-lib/aws-lambda';
 import { Construct } from 'constructs';
 import { Bundling } from './bundling';
+import { getCargoManifestPath } from './cargo';
 import { BundlingOptions } from './types';
 
 export { cargoLambdaVersion } from './bundling';
@@ -40,27 +39,10 @@ export interface RustFunctionProps extends lambda.FunctionOptions {
  */
 export class RustFunction extends lambda.Function {
   constructor(scope: Construct, packageName: string, props?: RustFunctionProps) {
-    // Find the package root
-    props = props ?? {};
-    const manifestPathProp = props.manifestPath ?? 'Cargo.toml';
-    const parsedManifestPath = path.parse(manifestPathProp);
-    let manifestPath: string;
-
-    if (parsedManifestPath.base && parsedManifestPath.ext && parsedManifestPath.base === 'Cargo.toml') {
-      if (!fs.existsSync(manifestPathProp)) {
-        throw new Error('Cargo.toml doesn\'t exist');
-      }
-      manifestPath = manifestPathProp;
-    } else if (parsedManifestPath.base && parsedManifestPath.ext && parsedManifestPath.base != 'Cargo.toml') {
-      throw new Error('manifestPath is specifying a file that is not Cargo.toml');
-    } else if (!fs.existsSync(path.join(manifestPathProp, 'Cargo.toml'))) {
-      throw new Error(`Cargo.toml file at ${manifestPathProp} doesn't exist`);
-    } else {
-      manifestPath = path.join(manifestPathProp, 'Cargo.toml');
-    }
+    const manifestPath = getCargoManifestPath(props?.manifestPath ?? 'Cargo.toml');
 
     const runtime = lambda.Runtime.PROVIDED_AL2;
-    const bundling = props.bundling ?? {};
+    const bundling = props?.bundling ?? {};
 
     super(scope, packageName, {
       ...props,
@@ -69,7 +51,7 @@ export class RustFunction extends lambda.Function {
         ...bundling,
         packageName,
         manifestPath,
-        binaryName: props.binaryName,
+        binaryName: props?.binaryName,
       }),
       handler: 'bootstrap',
     });

src/function.ts

@@ -1,2 +1,3 @@
+export * from './extension';
 export * from './function';
 export * from './types';

src/index.ts

@@ -1,3 +1,3 @@
 fn main() {
-    println!("Hello, world!");
+    println!("Hello, binary1!");
 }

test/fixtures/cargo-workspace/binary1/src/main.rs

@@ -1,3 +1,3 @@
 fn main() {
-    println!("Hello, world!");
+    println!("Hello, binary2!");
 }

test/fixtures/cargo-workspace/binary2/src/main.rs

@@ -1,15 +1,14 @@
 import * as path from 'path';
 import { env } from 'process';
 import * as cdk from 'aws-cdk-lib/core';
-import { RustFunction, cargoLambdaVersion } from '../lib/index';
+import { RustExtension, RustFunction, cargoLambdaVersion } from '../lib/index';
 
-describe('CargoLambda.RustFunction', () => {
-
-  const app = new cdk.App();
-  const stack = new cdk.Stack(app);
-  const forcedDockerBundling = !!env.FORCE_DOCKER_RUN || !cargoLambdaVersion();
+const forcedDockerBundling = !!env.FORCE_DOCKER_RUN || !cargoLambdaVersion();
 
+describe('CargoLambda.RustFunction', () => {
   describe('With single package Cargo project', () => {
+    const app = new cdk.App();
+    const stack = new cdk.Stack(app);
     const testSource = path.join(__dirname, 'fixtures/single-package');
 
     new RustFunction(stack, 'single-package', {
@@ -25,6 +24,8 @@ describe('CargoLambda.RustFunction', () => {
   });
 
   describe('With a Cargo workspace', () => {
+    const app = new cdk.App();
+    const stack = new cdk.Stack(app);
     const testSource = path.join(__dirname, 'fixtures/cargo-workspace');
 
     new RustFunction(stack, 'binary1', {
@@ -35,7 +36,6 @@ describe('CargoLambda.RustFunction', () => {
       },
     });
 
-
     new RustFunction(stack, 'binary2', {
       manifestPath: path.join(testSource, 'binary2'),
       binaryName: 'binary2',
@@ -48,4 +48,49 @@ describe('CargoLambda.RustFunction', () => {
       app.synth();
     });
   });
+});
+
+describe('CargoLambda.RustExtension', () => {
+  describe('With single package Cargo project', () => {
+    const app = new cdk.App();
+    const stack = new cdk.Stack(app);
+    const testSource = path.join(__dirname, 'fixtures/single-package');
+
+    new RustExtension(stack, 'single-package', {
+      manifestPath: testSource,
+      bundling: {
+        forcedDockerBundling,
+      },
+    });
+
+    test('bundle extension', () => {
+      app.synth();
+    });
+  });
+
+  describe('With a Cargo workspace', () => {
+    const app = new cdk.App();
+    const stack = new cdk.Stack(app);
+    const testSource = path.join(__dirname, 'fixtures/cargo-workspace');
+
+    new RustExtension(stack, 'binary1', {
+      manifestPath: path.join(testSource, 'binary1'),
+      binaryName: 'binary1',
+      bundling: {
+        forcedDockerBundling,
+      },
+    });
+
+    new RustExtension(stack, 'binary2', {
+      manifestPath: path.join(testSource, 'binary2'),
+      binaryName: 'binary2',
+      bundling: {
+        forcedDockerBundling,
+      },
+    });
+
+    test('bundle extension', () => {
+      app.synth();
+    });
+  });
 });