Prepare applications for deployment via CI

A common approach to deploying applications is via docker containers. Some applications can be built into bundles that are environment agnostic, while others depend on OS-specific packages being installed. For these situations, having just bundled code is not enough, we also need to have package.json.

Nx packages' executors support the generatePackageJson flag which tells the builder to also identify all dependencies and add them to package.json which is created next to the built artifacts (usually at dist/apps/name-of-the-app). Since version 15.3.3, the package.json generation will also include the appropriate lock file. This makes the installation in the container significantly faster.

Using a custom executor

If you are using a custom executor, you can still use Nx to generate package.json and the lock file. The createPackageJson and createLockFile functions are exported from @nrwl/devkit:

import { createPackageJson, createLockFile } from '@nrwl/devkit';
import { writeFileSync } from 'fs';

export default async function buildExecutor(
  options: Schema,
  context: ExecutorContext
) {
  // ...your executor code

  const packageJson = createPackageJson(
    context.projectName,
    context.projectGraph,
    {
      root: context.root,
      isProduction: true, // We want to strip any non-prod dependencies
    }
  );

  // do any additional manipulations to "package.json" here

  const lockFile = createLockFile(packageJson);
  writeJsonFile(`${options.outputPath}/package.json`, builtPackageJson);
  writeFileSync(`${options.outputPath}/${packageLockFileName}}`, lockFile, {
    encoding: 'utf-8',
  });

  // any subsequent executor code
}