You may experience an error in your Node.js application that many customers faced when first deploying such application on Scalingo. Here is a list of the most common error messages.

devDependencies Also Contain the Build Dependencies

The devDependencies section of the package.json file contains both development dependencies and build dependencies. By default Scalingo deployments install the dependencies from the dependencies section of the package.json file. It may lead to error messages such as ng: not found or nest: not found. In such situation, you have a couple of solutions:

• Install all devDependencies (doc).

  $ scalingo --app my-app env-set NPM_CONFIG_PRODUCTION=false
  

• Move the devDependencies needed for the build into the dependencies section of the package.json file.

Boot Timeout

You may see the following log lines at the end of your application deployment logs:

[...]
 Build complete, shipping your container...
 Waiting for your application to boot...
 !   Error deploying the application
 !   → Timeout: my-app took more than 60 seconds to boot
 !   Application Logs:  https://my.scalingo.com/apps/my-app/logs
 !   Documentation:     https://doc.scalingo.com/deployment/start-error#timeout

To ssh.osc-fr1.scalingo.com:my-app.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'ssh.osc-fr1.scalingo.com:my-app.git'

Most of the time, this timeout occurs when your application does not bind the port declared by the platform in the environment variable PORT. You can see how to do that in this Express example.

Here is a short excerpt of this example:

var express = require('express')
var app = express()

var server = app.listen(process.env.PORT || 3000, function () {
  var host = server.address().address
  var port = server.address().port
  console.log('App listening at http://%s:%s', host, port)
})

If you face a boot timeout error and use the Next.js framework, please refer to this specific page.

Host key verification failed

Installing node modules
npm ERR! Error while executing:
npm ERR! /usr/bin/git ls-remote -h -t ssh://git@github.com/scalingo/scalingo.js.git
npm ERR!
npm ERR! Host key verification failed.
npm ERR! fatal: Could not read from remote repository.
npm ERR!
npm ERR! Please make sure you have the correct access rights
npm ERR! and the repository exists.
npm ERR!
npm ERR! exited with error code: 128
-----> Build failed

This issue happens when in your package.json you’re using a git repository instead of a npm package. If you are doing that, you can only use the https format and not the ssh one.

These requirements correctly resolve to HTTPS URLs:

"scalingo": "https://git@github.com/scalingo/scalingo.js.git"
"scalingo": "git+https://git@github.com/scalingo/scalingo.js.git"

These requirements incorrectly resolve to SSH URLs:

"scalingo": "github:scalingo/scalingo.js"
"scalingo": "https://github.com/scalingo/scalingo.js.git"
"scalingo": "git+https://github.com/scalingo/scalingo.js.git"
"scalingo": "git@github.com:Scalingo/scalingo.js.git"