davesag/microservice-generator

An opinionated generator for Swagger based Rest API servers

microservice-generator

An opinionated generator for Swagger based Rest API servers

Prerequisites

This library assumes you are using NodeJS 12.18.2+

Install

Note: This project is currently in development and not ready to be installed.

Run (proposed command-line interface)

ms-new path/to/api.yml [--gateway --api --output path/to/output/dir]

This will read your swagger formatted api.yml file and do the following

1. Generate boilerplate

   • package.json file,
   • various dotfiles,
   • a CONTRIBUTING.md file,
   • a README.md file
   • a .circleci/config.yml file
   • a src folder as described below,
   • a test folder as described below

2. Generate Project source

   src/
     api/
       index.js
       ping.js
       versions.js
     events/
       registerService.js
     models/
       index.js
     serialisers/
     utils/
       apiValidator.js
       appMaker.js
       config.js
       genericErrors.js
       handleMigrationError.js
       logger.js
       makeUri.js
       messageMaker.js
       uptime.js
     errors.js
     exchange.js
     index.js
     server.js
     service.js
   

3. Generate Tests

   test/
     db/
       models/
       _.spec.js
       test_helper.js
     server/
       routes/
       _.spec.js
       test_helper.js
     unit/
       api/
       events/
       models/
       serialisers/
       utils/
         apiValidator.spec.js
         appMaker.spec.js
         genericErrors.spec.js
         handleMigrationError.spec.js
         makeUri.spec.js
         messageMaker.spec.js
         uptime.spec.js
       server.spec.js
       service.spec.js
       test_helper.js
       utils/
         data/
           index.js
         eventTest.js
         mockApi.js
         mockLogger.js
         mockSerialiser.js
         mockService.js
     .eslintrc.js
   

4. Generate supporting files and dotfiles

   config/
     db_config.yml
   migrations/
   tasks/
     generateERD/
       index.js
     initDb/
       index.js
     migrationConfig.js
   .circleci/
     config.yml
   .eslintrc.js
   .eslintignore
   .gitignore
   .prettiergnore
   .sequelizerc
   api.yml
   CONTRIBUTING.md
   Dockerfile
   docker-compose.yml
   index.js
   Procfile
   

5. For each path extract the path details and the corresponding operationId and generate the following

   src/api/{basename}/
     {operationId}.js // folder paths are generated as required
   test/unit/api/{basename}
     {operationId}.spec.js
   test/server/routes/{basename}
     {operationId}.spec.js
   

6. For each definition in the definitions section

   migrations/
     {timestamp}-create-{plural(definition)}.js
   src/models/
     {definition}.js
   test/unit/models/
     {definition}.spec.js
   test/db/models/
     {definition}.spec.js
   test/utils/data/
   {definition}Data.js
     make{operationId}.js
   

Once these files have been generated, you can then start filling in whatever implementation details you wish. Where possible the generator will fill in complete code. Where not possible it will generate working stubs and some documentation to get you going.

Parameters and Options

ms-new takes the following parameters

• The path to a swagger YAML file.

• --gateway Tells the generator you are generating an api gateway, not an underlying service.

• --output path/to/output/dir Tells the generator which folder to write files to. Note that folder must be empty apart from the following files or directories which will be ignored.

  .git/
  .gitignore
  LICENCE
  README.md
  {api.yml} // whatever name you specified when you invoked the generator
  

Once you have generated a server

cd into your server folder if you need to, then

npm install
npm test
npm run backend
npm run test:db
npm run test:server
npm start

The service's tests should all pass and it should run, it should expose an api, and, if it's a microservice it should emit a heartbeat event to rabbitmq.

If it's a gateway service then it will listen for heartbeat events and keep track of the services and their access tokens.

It will expose the rest api outlined in the swagger documentation and link those paths to their nominated routes. These routes will simply emit example data.

Now write some code

Models

Overwrite the generated tests and source models to suit your own needs.

Route Controllers

The default route controller will be an async function that includes code to read any of the params defined, and to emit the relevant errors or response. The specifics of how the response is generated are left to you.

Controllers for the ping and versions root level functions common to all servers are installed along with their corresponding unit and integration tests.

Services

Service definition is not covered in the swagger file, so we leave this blank apart from the default heartbeat service

Migrations

The default migrations are certain to be lacking some subtlety.

Development

You may add environment variables to your local .env file

Branches

Branch	Tests	Code Coverage	Audit	Comments
develop				Work in progress
main				Latest stable release

Prerequisites

• NodeJS. I use nvm to manage Node versions — brew install nvm.
• Docker (if on a Mac then use Docker for Mac, not the homebrew version)

Initialisation

npm install

Starting the server and syncing the database with the model definitions.

Before you run the server you will need to set up the database.

npm run db:init

then

npm run db:migrate

then you can

npm start

Test it

• npm test — runs the unit tests (quick)

Lint it

npm run lint

To auto-fix linting issues.

npm run lint -- --fix

Make the code prettier

This runs on every commit but you can do this manually as well via:

npm run prettier

Contributing

Please see the contributing notes.