12 factor node app

This example allows you to understand how 12 factor applications are built.

Instruments for work with this repo

• docker
• docker-compose
• IDE (Vscode etc.)

Steps for build this application:

• install docker
• install docker-compose
• run docker-compose up in the first terminal
• run curl http://0.0.0.0:13000/users in another console

Most important moments:

• almost all configurations for this application we get from the environment variables.

let mongoHost = process.env.MONGO_HOST;

• all logs we send to the stdout

console.log(`Connecting to url for ${attempt + 1} attempt: ${url}`);

• we logging everything, errors, success, put, get, delete, all operations must be written to the stdout

• health status for our application for the database:

  app.get('/readiness', (req, res) => {
    let status = isReady ? 200 : 500;
    res.sendStatus(status);
   });
  

  and for application:

  app.get('/health', (req, res) => {
  res.sendStatus(200);
   });
  

Must have links:

• https://12factor.net/
• https://www.linode.com/docs/applications/containers/how-to-use-docker-compose/
• https://docker-curriculum.com/