I am getting an “Invalid Host header” message when connecting to webpack-dev-server remotely

Question

I am using as an environment, a Cloud9.io ubuntu VM Online IDE and I have reduced by troubleshooting this error to just running the app with Webpack dev server.

I l

Answer 1

Rather than editing the webpack config file, the easier way to disable the host check is by adding a .env file to your root folder and putting this:

DANGEROUSLY_DISABLE_HOST_CHECK=true

As the variable name implies, disabling it is insecure and is only advisable to use only in dev environment.

Answer 2

If you are using create-react-app on C9 just run this command to start

npm run start --public $C9_HOSTNAME

And access the app from whatever your hostname is (eg type $C_HOSTNAME in the terminal to get the hostname)

Answer 3

Hello React Developers,

Instead of doing this disableHostCheck: true, in webpackDevServer.config.js. You can easily solve 'invalid host headers' error by adding a .env file to you project, add the variables HOST=0.0.0.0 and DANGEROUSLY_DISABLE_HOST_CHECK=true in .env file. If you want to make changes in webpackDevServer.config.js, you need to extract the react-scripts by using 'npm run eject' which is not recommended to do it. So the better solution is adding above mentioned variables in .env file of your project.

Happy Coding :)

Answer 4

The more secure option would be to add allowedHosts to your Webpack config like this:

module.exports = {
devServer: {
 allowedHosts: [
  'host.com',
  'subdomain.host.com',
  'subdomain2.host.com',
  'host2.com'
   ]
  }
};

The array contains all allowed host, you can also specify subdomians. check out more here

Answer 5

This is what worked for me:

Add allowedHosts under devServer in your webpack.config.js:

devServer: {
  compress: true,
  inline: true,
  port: '8080',
  allowedHosts: [
      '.amazonaws.com'
  ]
},

I did not need to use the --host or --public params.

Answer 6

I found out, that I need to set the public property of devServer, to my request's host value. Being that it will be displayed at that external address.

So I needed this in my webpack.config.js

devServer: {
  compress: true,
  public: 'store-client-nestroia1.c9users.io' // That solved it
}

Another solution is using it on the CLI:

webpack-dev-server --public $C9_HOSTNAME <-- var for Cloud9 external IP