Example of generating docker containers url routes for proxy configurations

api-gateway.docker.js

'use strict'
const Docker = require('dockerode')

const discoverRoutes = (container) => {
  return new Promise((resolve, reject) => {
    // here we retrieve our dockerSettings
    const dockerSettings = container.resolve('dockerSettings')
  
    // we instatiate our docker object, that will communicate with our docker-machine
    const docker = new Docker(dockerSettings)
  
    // function to avoid registering our database route and api route 
    const avoidContainers = (name) => {
      if (/mongo/.test(name) || /api/.test(name)) {
        return false
      }
      return true
    }
    
    // here we register our routes in our ES6 proxy object
    const addRoute = (routes, details) => {
      routes[details.Id] = {
        id: details.Id,
        name: details.Names[0].split('').splice(1).join(''),
        route: details.Labels.apiRoute,
        target: getUpstreamUrl(details)
      }
    }
    
    // we generate the container url to be proxy
    const getUpstreamUrl = (containerDetails) => {
      const {PublicPort} = containerDetails.Ports[0]
      return `http://${dockerSettings.host}:${PublicPort}`
    }
    
    // here we list the our running containers
    docker.listContainers((err, containers) => {
      if (err) {
        reject(new Error('an error occured listing containers, err: ' + err))
      }

      const routes = new Proxy({}, {
        get (target, key) {
          console.log(`Get properties from -> "${key}" container`)
          return Reflect.get(target, key)
        },
        set (target, key, value) {
          console.log('Setting properties', key, value)
          return Reflect.set(target, key, value)
        }
      })

      containers.forEach((containerInfo) => {
        if (avoidContainers(containerInfo.Names[0])) {
          addRoute(routes, containerInfo)
        }
      })
     
      // and finally we resolve our routes
      resolve(routes)
    })
  })
}

module.exports = Object.assign({}, {discoverRoutes})