gistfile1.js

module.exports = function(topic) {
  return {
    topic: topic,
    command: 'create',
    description: 'creates a local development environment',
    help: `help text for ${topic}:create`,
    flags: [
      { name: 'template', description: 'create a Dockerfile based on a language template', hasValue: true }
    ],
    run: function(context) {
      console.log('context:', context.command.flags);
      console.log('args:', context.args);
      createDockerfile(context.cwd, context.args.template);
      createImage(context.cwd);
    }
  };
};

$ heroku docker:create --template=node
context: [ { name: 'template',
char: '',
description: 'create a Dockerfile based on a language template',
hasValue: true } ]
args: {}

$ heroku docker:create --template node
context: [ { name: 'template',
char: '',
description: 'create a Dockerfile based on a language template',
hasValue: true } ]
args: { template: 'node' }