Update the images for a docker stack file from swarm

update-stack.js

#!/usr/bin/env node
const fs = require('fs')
const { execSync } = require('child_process');
const args = process.argv.slice(2)
const stack = args[0]
const stackfile = stack+'.yml'
const SWARM_SERVICES_RAW = execSync(`docker service ls | grep ${stack} | awk '{print $5}'`)
const STACKFILE_SERVICES_RAW = execSync(`cat ${stackfile} | grep image | awk '{print $2}'`)

let swarm_services = SWARM_SERVICES_RAW.toString().split('\n')
  .filter(s => s != '')
let stackfile_services = STACKFILE_SERVICES_RAW.toString().split('\n')
  .filter(s => s != '')

async function main() {
  for (let image of stackfile_services) {
    let _image = image.split(':')
    let service = _image[0]+':'+_image[1]
    let version = _image[2]
    let swarm_service = swarm_services.reduce((match, ss) => {
      if (ss.indexOf(service) === 0) return ss
      return match
    }, null)
    if (!swarm_service) continue
    if (image === swarm_service) continue
    console.log(image+' -> '+swarm_service)
    await replace(image, swarm_service)
  }
}

async function replace(to_replace, replacement) {
  var data = await readFile(stackfile)
  var re = new RegExp(to_replace, 'g');
  var result = data.replace(re, replacement)
  await writeFile(stackfile, result)
}

const readFile = filePath => new Promise((resolve, reject) => {
  fs.readFile(filePath, 'utf8', (err, data) => {
    if (err) reject(err);
    else resolve(data);
  })
})

const writeFile = (filePath, content) => new Promise((resolve, reject) => {
  fs.writeFile(filePath, content, 'utf8', (err, data) => {
    if (err) reject(err);
    else resolve(data);
  })
})

main()