Lambda fails with "Cannot find module..."

Question

I'm packing my lambdas with Webpack. And I'm deploying them with CDK.

However, when testing them through ApiGateway, I get this:

Lambda execution failed with status 200 due to customer function error: Error: Cannot find module 'apollo-server-lambda'.

Here's my Webpack config:

{
  mode: 'production',
  entry: {
    graphql: './src/lambdas/graphql.ts',
    cognito: './src/lambdas/cognito.ts',
    'smoke-detector': './src/lambdas/smoke-detector.ts',
  },
  output: {
    libraryTarget: 'commonjs',
    path: path.resolve(__dirname, "dist"),
    filename: '[name]/[name].js'
  },
  target: 'node',
  externals: [nodeExternals()],
  resolve: {
    extensions: ['.ts', '.js']
  },
  module: {
    rules: [
      loader({
        test: /\.ts$/,
        use: {
          loader: 'ts-loader',
          options: {
            getCustomTransformers: () => ({
              before: [graphqlTag.getTransformer()]
            })
          }
        }
      }),
      loader({
        test: /\.graphqls$/,
        use: {
          loader: 'graphql-tag/loader',
        }
      })
    ]
  },
  plugins: [
  ]
}

Executing the output file like node graphql.js doesn't fail. What am I doing wrong?

Answer 1

Removing

externals: [nodeExternals()]

fixed the problem.

It caused dependencies to be excluded from the bundle.