Typescript Docker Starter

This repository is an application template using Docker with Alpine Linux, Node LTS, and Typescript. It starts and exposes a web server on port 5000 that returns a hello world HTML page for all requests.

Installation

1. Install Docker, if you have not already done so.

2. Clone or download this repository. If starting a new project, you may want to use degit to clone and strip the git history:

    npx degit valtech-sd/ts-docker-starter ./my-new-docker-app  
   

3. From the root of this repository, before running the container for the first time:

   • You may need to build its image locally with docker build ..
   • Install the node modules with npm i. (Docker currently pulls in the whole local repository folder as a mounted volume; this practice might change in the future for deploying to servers.)
   • Generate the .js files from Typescript by running npm run build.

4. Start Docker with docker-compose run --rm --service-ports node

   • --rm removes the container after it runs, to clean up
   • --service-ports makes sure that the port-forwarding works (it does not forward by default)
   • starts the node service in the docker-compose.yml and runs the npm start script

What is in this starter project?

Docker with Node.js LTS

We have a simple Dockerfile and use docker-compose.yml to put most command line parameters into YAML configuration instead.

This repository uses the official Node Docker image for LTS on Alpine Linux. There are a few issues associated with this image (it uses a different libc module — musl libc instead of glibc), and the Node team provides a set of best practices that we have read and should follow on projects.

• ✔️ Run as node user, instead of root.

• ✔️ Use environment variable NODE_ENV=production.

• ✔️ Put global dependencies in non-root user directory.

• ... Limit how much memory the container consumes.

• ... Run Docker Bench for Security audit script.

• ... Bake startup script directly into Dockerfile with

      CMD ["node","index.js"]
  

  (or use init).
  See docker-compose.yml comments.

Note: If you are using VSCode, there is an official Docker extension to make it easier to manage your containers.

TypeScript

There is a tsconfig.json in the root directory. Per TypeScript's defaults, we

• keep source .ts files in ./src
• generate .js files in ./built.

To rebuild, type npm run build, which will

• run rimraf on the ./built folder (clears everything with a rm -rf)
• build with tsc

ESLint

.eslintrc is the JSON configuration file for ESLint created by running npx eslint --init. It should be set up with TypeScript formatting, and correct double-quotes to single quotes for consistency.

Prettier

.prettierrc is the JSON configuration file for Prettier. Currently, it only enforces single quotes.

Mocha

Tests are configured for mocha. Node looks in the standard ./test folder for tests.

• mocha and the @types/mocha type definitions are dev dependencies.
• There is an npm run test script that calls mocha and registers it with ts-node so that tests can be written in TypeScript.

Note: If you're using VSCode, there is a .vscode/launch.json set up for easier debugging.

Future work

• Refine this repository as our needs and understanding of Docker grow.
• Determine our best practice for mounting data volumes. (Here is a potential issue to watch out for.)