cli.js

#!/usr/bin/env node
const { Command } = require('commander');
const toml = require('toml');
const fs = require("fs/promises");
const { CloudFormationClient, DescribeStacksCommand } = require("@aws-sdk/client-cloudformation");
const program = new Command();

const REQUIRED_KEYS = [
  "Region",
  "ApiEndpoint",
  "CognitoUserPoolID",
  "CognitoWebClientID",
]

const writeConfigFile = (src, dest, configMap) => fs
  .readFile(src)
  .then(data => Object.entries(configMap).reduce((acc, [k, v]) => acc.replace(`<${k}>`,v), data.toString()))
  .then(data => fs.writeFile(dest, data))
;

const getOutputs = async (stackName, region=null) => {
  const clientConfig = {};
  if (region) clientConfig.region = region;
  const client = new CloudFormationClient(clientConfig);
  const command = new DescribeStacksCommand({
    StackName: stackName
  });
  const res = await client.send(command);
  const stack = res.Stacks.find(i => i.StackName === stackName);
  if (!stack) throw new Error("Stack not found");
  const outputMap = stack.Outputs.reduce((acc, next) => ({
    ...acc,
    [next.OutputKey]: next.OutputValue
  }), {});
  if (REQUIRED_KEYS.some(i => !(i in outputMap))) throw new Error(`Stack outputs missing required keys: ${JSON.stringify(outputMap)}`);
  return outputMap;
}

const getStackDetails =(configFile, env) => {
  return fs.readFile(configFile)
    .then(data => toml.parse(data))
    .then(data => data[env].deploy.parameters)
    .then(data => ({
      stackName: data.stack_name,
      region: data.region,
    }))
}

const generateConfig = (options) => {
  const {
    samConfig,
    samConfigEnv,
    debug
  } = options;

  if (debug) {
    console.debug(`SAM config file: ${samConfig}`)
    console.debug(`SAM config env: ${samConfigEnv}`)
  }

  getStackDetails(samConfig, samConfigEnv)
    .then(details => getOutputs(details.stackName, details.region))
    .then(stackOutputs => writeConfigFile(".env.template", ".env.local", stackOutputs))
    .then(() => console.log("Config generated successfully!"))
    .catch((err) => console.error(`Failed to generate config file: ${err}`));
}

const echoOutput = (output) => (options) => {
  const {
    samConfig,
    samConfigEnv,
    debug
  } = options;

  if (debug) {
    console.debug(`SAM config file: ${samConfig}`)
    console.debug(`SAM config env: ${samConfigEnv}`)
  }

  getStackDetails(samConfig, samConfigEnv)
    .then(details => getOutputs(details.stackName, details.region))
    .then(stackOutputs => console.log(stackOutputs[output]));
}

const echoBucket = echoOutput("WebUIBucket");
const echoUrl = echoOutput("WebUrl");

const makeCommand = (name, desc, handler) => program
  .command(name)
  .option('-c, --sam-config <file>', "The SAM config toml file generated when deploying the solution", "samconfig.toml")
  .option('-e, --sam-config-env <env>', "The SAM environment to use to generate the config file", "default")
  .option('-d, --debug', "Whether to debug")
  .description(desc)
  .action(handler)
;

makeCommand("generate-config", "Generates a frontend configuration file for the AWS MediaLive Channel Orchestrator", generateConfig)
makeCommand("echo-bucket", "Prints the frontend UI bucket name", echoBucket)
makeCommand("echo-url", "Prints the deployed frontend URL", echoUrl)

program.parse(process.argv);