dbctl-server.js

const url = require('url')
const qs = require('querystring')
const path = require('path')
const fs = require('fs')

const { createServer } = require('http')
const { exec } = require('child_process')

const envFile = fs.readFileSync(path.resolve(__dirname, 'dbctl.env'), { encoding: 'utf8' })

envFile.split('\\n').forEach(pair => {
  const [key, val] = pair.split('=')
  if (key && val) process.env[key] = val
})

const execCmd = (cmd, env) => new Promise((resolve, reject) => {
  exec(cmd, {env: process.env}, (err, stdout, stderr) => {
    return err ? reject(err) : resolve([stdout, stderr])
  })
})

const bucket = process.env.BACKUPS_BUCKET_URL

const controller = {
  dump: (req, res) => {
    const timestamp = Date.now()
    const filename = timestamp + '.dump.sql'

    return execCmd('pg_dump -f /tmp/' + filename)
      .then(() => execCmd('aws s3 cp /tmp/' + filename + ' ' + bucket + '/' + filename))
      .then(() => execCmd('rm /tmp/' + filename))
      .then(() => res.end(bucket + '/' + filename))
      .catch(e => errResponse(e, res))
  },
  pull: (req, res) => {
    const timestamp = qs.parse(req.url.query).timestamp
    if (!timestamp) throw new Error('No timestamp provided')
    const filename = timestamp + '.dump.sql'

    return execCmd('aws s3 cp ' + bucket + '/' + filename + ' /tmp/' + filename)
      .then(() => {
        fs.readFile('/tmp/' + filename, (err, file) => {
          if (err) throw err
          return execCmd('rm /tmp/' + filename)
            .then(() => res.end(file))
        })
      })
      .catch(e => errResponse(e, res))
  },
  restore: (req, res) => {
    const timestamp = qs.parse(req.url.query).timestamp
    if (!timestamp) throw new Error('No timestamp provided')
    const filename = timestamp + '.dump.sql'

    return execCmd('aws s3 cp ' + bucket + '/' + filename + ' /tmp/' + filename)
      .then(() => execCmd('psql < /tmp/' + filename))
      .then(([stdout]) => {
        return execCmd('rm /tmp/' + filename)
          .then(() => res.end(stdout))
      })
      .catch(e => errResponse(e, res))
  }
}

const errResponse = (err, res) => {
  console.error(err)
  res.statusCode = 500
  res.end(err.message || 'Server error')
}

createServer((req, res) => {
  req.url = url.parse(req.url)
  try {
    switch (req.url.pathname) {
      case '/dump': return controller.dump(req, res)
      case '/pull': return controller.pull(req, res)
      case '/restore': return controller.restore(req, res)
      default: return res.end('Invalid route')
    }
  } catch(e) {
    return errResponse(e, res)
  }
}).listen(3333)