wip - moving to dual output for x64 and arm64

Author: cbschuld

webpack.config.js

@@ -2,77 +2,105 @@ const path = require('path');
 const CopyPlugin = require('copy-webpack-plugin');
 const ZipPlugin = require('zip-webpack-plugin');
 
+// Read the target architecture from the environment variable set in Dockerfile
 const targetArch = process.env.TARGET_ARCH; // Should be 'x64' or 'arm64'
 if (!targetArch) {
   throw new Error("TARGET_ARCH environment variable not set!");
 }
 
-const targetPlatform = 'linux';
+// Determine the correct platform (should always be linux in this build environment)
+const targetPlatform = 'linux'; // We are building in a linux container
 
-// --- START: Adjust filename based on arch ---
 // Determine the specific suffix used in the .node filename
 let nodeArchSuffix = targetArch; // Default to 'x64' or 'arm64'
 if (targetArch === 'arm64') {
   nodeArchSuffix = 'arm64v8'; // Use the suffix found in the logs for arm64
 }
 // Construct the final .node filename
 const nodeFileSuffix = `sharp-${targetPlatform}-${nodeArchSuffix}.node`;
-// --- END: Adjust filename based on arch ---
-
 
+// Define the output path structure for Lambda layers
 const layerBasePath = 'nodejs/node_modules/sharp';
-// This path used internally by Sharp's JS code must match the actual .node file
+
+// Define the relative path that sharp's JS code uses to require the native module.
+// This is typically '../build/Release/...' relative to files in 'lib/'
 const sharpInternalRequirePath = `../build/Release/${nodeFileSuffix}`;
 
 console.log(`Webpack config: Building for ${targetPlatform}-${targetArch}`);
-// This log will now show 'sharp-linux-arm64v8.node' for arm builds
 console.log(`Webpack config: Expecting native module: ${nodeFileSuffix}`);
 console.log(`Webpack config: Marking require path as external: ${sharpInternalRequirePath}`);
 
 module.exports = {
-  name: `layer-${targetArch}`,
+  name: `layer-${targetArch}`, // Give the config a name incorporating the arch
   mode: 'production',
   stats: 'minimal',
-  target: 'node',
+  target: 'node', // Important: ensures Webpack uses Node.js style externals/requires
   watch: false,
   entry: {
+    // Entry point for Sharp's main lib
     [`${layerBasePath}/index`]: './node_modules/sharp/lib/index.js',
   },
   plugins: [
-      new CopyPlugin({
-        patterns: [
-          {
-            // This 'from' pattern now uses the correct filename for arm64v8
-            from: `node_modules/sharp/build/Release/${nodeFileSuffix}`,
-            to: `${layerBasePath}/build/Release/${nodeFileSuffix}`, // Copy to the same relative path
-          },
-          // Other patterns remain unchanged
-          { from: 'node_modules/sharp/LICENSE', to: layerBasePath },
-          { from: `node_modules/sharp/vendor`, to: `${layerBasePath}/vendor` },
-          { from: `node_modules/sharp/package.json`, to: layerBasePath },
-        ],
-      }),
-      new ZipPlugin({
-        // Keep the output ZIP name user-friendly (arm64, not arm64v8)
-        filename: `sharp-layer-${targetArch}.zip`,
-        pathPrefix: '',
-      })
+    new CopyPlugin({
+      patterns: [
+        {
+          // Copy the compiled native module build ('Release' directory)
+          // to the location expected by the runtime require
+          from: `node_modules/sharp/build/Release/${nodeFileSuffix}`,
+          to: `${layerBasePath}/build/Release/${nodeFileSuffix}`, // Keep the same structure relative to 'lib'
+        },
+        {
+          from: 'node_modules/sharp/LICENSE',
+          to: layerBasePath,
+        },
+        {
+          // Copy vendor libraries (like libvips) installed for the target arch
+          from: `node_modules/sharp/vendor`,
+          to: `${layerBasePath}/vendor`,
+        },
+         {
+          // Copy Sharp's package.json - sometimes needed for runtime checks
+          from: `node_modules/sharp/package.json`,
+          to: layerBasePath,
+        },
+        // Add any other necessary files from sharp's node_modules directory
+      ],
+    }),
+    new ZipPlugin({
+      // Create an architecture-specific filename
+      filename: `sharp-layer-${targetArch}.zip`,
+      // Specify the base directory for files inside the zip
+      // This ensures the 'nodejs/...' structure is at the root of the zip
+      pathPrefix: '',
+    })
   ],
   optimization: {
-    minimize: false,
+    minimize: false, // Lambda layers generally shouldn't minimize node_modules internals
   },
   output: {
-    filename: '[name].js',
-    path: path.resolve(__dirname, 'dist'),
+    filename: '[name].js', // Output filename for the entry point JS
+    path: path.resolve(__dirname, 'dist'), // Output directory for webpack build artifacts (including the zip)
     libraryTarget: 'commonjs2',
   },
   externals: {
-     // The key here now correctly matches the require path for arm64v8
+    // *** Tell Webpack NOT to bundle the .node file ***
+    // Map the internal require path used by Sharp to a commonjs external type.
+    // This leaves the require statement intact for the Node.js runtime.
     [sharpInternalRequirePath]: `commonjs ${sharpInternalRequirePath}`
   },
+  // Ensure node module resolution works
   resolve: {
     modules: [path.resolve(__dirname, 'node_modules'), 'node_modules'],
   },
-  // Keep node-loader removed for now, since x64 worked without it.
-  // module: { rules: [ /* node-loader rule */ ] },
+  module: {
+    rules: [
+      {
+        test: /\.node$/,
+        loader: 'node-loader',
+        options: {
+          name: '[path][name].[ext]', // Keep original path/name
+        },
+      },
+    ],
+  },
 };