index.js

const URL = require('url')
const QS = require('qs')
const { createElement } = require('react')
const { renderToString } = require('react-dom/server')
const { createServer } = require('http')
const logger = require('connect-logger')
const connect = require('connect')

const components = require('./components')

const PORT = process.env.PORT || 8080

const app = connect()
app.use(logger())

app.use('/', (request, response) => {
  const { url } = request
  const { query } = URL.parse(url)
  const { name, props } = QS.parse(query)
  const component = components[name]

  if (!component) {
    response.statusCode = 404
    return response.end(JSON.stringify({
      error: { message: 'Unknown component' }
    }))
  }

  response.statusCode = 200
  response.end(JSON.stringify({
    content: renderToString(
      createElement(component, props)
    )
  }))
})

const server = createServer(app).listen(PORT, () => {
  const { address, port } = server.address()
  console.log(`View server listening on ${address}:${port}`)
})

package.json

{
  "name": "view-server",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "connect": "^3.6.0",
    "connect-logger": "^0.0.1",
    "qs": "^6.3.1",
    "react": "^15.4.2",
    "react-dom": "^15.4.2"
  }
}