feat: allow to download .env file with build environment variables from S3 to a local dev environment

[tmokmss]

Usage

1. add outputEnvFile flag, and run cdk deploy.

    new NodejsBuild(this, 'ExampleBuild', {
      assets: [
        {
          path: 'example-app',
          exclude: ['dist', 'node_modules'],
        },
      ],
      destinationBucket: dstBucket,
      outputSourceDirectory: 'dist',
      buildCommands: ['npm ci', 'npm run build'],
      buildEnvironment: {
        VITE_API_ENDPOINT: api.url,
        VITE_BUKCET_NAME: dstBucket.bucketName,
      },
      outputEnvFile: true, // ADD THIS FLAG
    });

2. you will get stack outputs like this:

 ✅  NodejsTestStack

✨  Deployment time: 278.49s

Outputs:
NodejsTestStack.ExampleBuildDownloadEnvFileC240151B = aws s3 cp s3://cdk-hnb659fds-assets-123456789012-ap-northeast-1/deploy-time-build/NodejsTestStack/ExampleBuild61F1D79B/6a4113a1b53dee719f931a51321ecec7.env .env.local

3. run the command in your local machine, and you will get your .env file.

$ aws s3 cp s3://cdk-hnb659fds-assets-123456789012-ap-northeast-1/deploy-time-build/NodejsTestStack/ExampleBuild61F1D79B/6a4113a1b53dee719f931a51321ecec7.env .env.local
$ cat .env.local
VITE_API_ENDPOINT=https://asdfg.execute-api.ap-northeast-1.amazonaws.com/prod/
VITE_BUKCET_NAME=nodejsteststack-dstbucket3e241bf2-dwmxxxx