Pulumi resource to execute a shell command localy

shellCommand.ts

import * as pulumi from "@pulumi/pulumi";

// Use like this:
// var command = "docker ps -a"
// const myResource = new ShellCommand("List Files", {command: command, env: {'FOO': 'bar'}, runAllways: false});

export interface ShellCommandArgs {
  uniqueId?: pulumi.Input<string>;
  command: pulumi.Input<string>;
  env: object;
  runAllways?: pulumi.Input<boolean>;
}

interface ShellCommandProviderArgs {
  uniqueId: string;
  command: string;
  env: object;
  runAllways?: boolean;
}

const commandProp = "command";
const runAllwaysProp = "runAllways";

// a resource to execute a shell script
// the script will
//
// idea taken from: https://github.com/pulumi/examples/blob/master/azure-ts-static-website/staticWebsite.ts
// details to Dynamic Providers: https://www.pulumi.com/docs/intro/concepts/programming-model/#dynamicproviders
const shellCommandProvider: pulumi.dynamic.ResourceProvider = {
  async create(inputs: ShellCommandProviderArgs) {
    const { execSync } = require("child_process");
    execSync(inputs.command, {
      env: inputs.env ? inputs.env : {},
      stdio: "inherit",
    });

    return { id: `${inputs.uniqueId}ShellCommand`, outs: {} };
  },

  async check(
    olds: ShellCommandProviderArgs,
    news: ShellCommandProviderArgs
  ): Promise<pulumi.dynamic.CheckResult> {
    const failures = [];
    if (news.command === undefined) {
      failures.push({
        property: commandProp,
        reason: `required property '${commandProp}' missing`,
      });
    }

    // if undefined: allways run
    if (news.runAllways == undefined || news.runAllways) {
      news.runAllways = true;
    }

    return { inputs: news, failures };
  },

  async diff(
    id: pulumi.ID,
    olds: ShellCommandProviderArgs,
    news: ShellCommandProviderArgs
  ): Promise<pulumi.dynamic.DiffResult> {
    const replaces = [];
    if (olds[commandProp] !== news.command) {
      // FIXME for some reason this `olds.command` currently is allways `undefined`
      // -> command will allways be exected
      pulumi.log.warn(
        `command changed: old=${olds.command}, new=${news.command}`
      );
      replaces.push(commandProp);
    }
    var hasChanges = replaces.length > 0;
    if (news.runAllways === true) {
      hasChanges = true;
    }
    return { replaces, changes: hasChanges };
  },
};

export class ShellCommand extends pulumi.dynamic.Resource {
  constructor(
    name: string,
    props: ShellCommandArgs,
    opts?: pulumi.CustomResourceOptions
  ) {
    super(shellCommandProvider, name, { ...props, uniqueId: name }, opts);
  }
}