Node.js app 404 errors for public directory in Google App Engine Flexible production environment

Question

I've been working with the Node.js Google App Engine for some months and have always successfully used the express.static solution to access static files in the public folder when i deployed my node.js app.

For some (to me not so obvious) reason I struggle to get this working lately in the Google Flexible production environment. On my local development environment everything is fine.

In order to narrow down the problem I created a very basic test app listed here:

    'use strict'

const express = require('express')
const app     = express()
const path    = require('path')
const os      = require('os')
const PORT    = process.env.PORT || 8080
const ENV     = process.env.NODE_ENV

//app.use(express.static('public'))
//app.use(express.static(path.resolve(__dirname, 'public')))
app.use(express.static(path.join(__dirname, 'public')))

app.listen(PORT, () => {
 console.log(`SYSTEM: App listening on port ${PORT}`)
 console.log(`SYSTEM: Press Ctrl+C to quit.`)
})

app.get('/', (req,res) => {
 res.status(200).send('\
  <h1>TEST app.use(express.static("public")) in Google Cloud Flexibel App     Engine environment </h1>\
  <hr/>\
  <h4>YAML settings: runtime: nodejs env: flex</h4>\
  <h4>HOST         : '+`${os.hostname()}`+'</h4>\
  <h4>PORT         : '+`${PORT}`+'</h4>\
  <h4>__dirname    : '+`${__dirname}`+'</h4>\
  <h4>mountpath    : '+`${app.mountpath}`+'</h4>\
  <h4>env          : '+`${ENV}`+'</h4>\
  <h4>path resolved: '+`${path.resolve(__dirname, 'public')}`+'</h4>\
  <h4>path joined  : '+`${path.join(__dirname, 'public')}`+'</h4>\
  <hr/>\
  <h2>If you see me <img src="./HB.png"> you can access "./HB.png" in the "public" directory.</h2>\
  <h2>If you see me <img src="/HB.png">  you can access "/HB.png"  in the "public" directory.</h2>\
  <h2>If you see me <img src="HB.png">   you can access "HB.png"   in the "public" directory.</h2>\
  <hr/>\
 ')
})

I tried various settings of the express.static settings (see those commented out). However each time after deploying using gcloud app deploy to Google production I get 404 (also in the google logs). On local development environment everything is fine.

Does anyone have a clue ? Thanks in advance !

Answer 1

Strange, I solved it by reinstalling the Google Cloud SDK.