Local Environment CORS Error

Help me!
1

Feature(s) impacted

Local Dev Environment Authentication

Observed behavior

Unable to access local dev environment due to CORS error

Expected behavior

Access to local dev environment

Failure Logs

Console log message:

Access to fetch at 'http://localhost:3310/forest/authentication' from origin 'https://app.forestadmin.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Private-Network' header was present in the preflight response for this private network request targeting the local address space.

Context

Yesterday, I was able to access my local development environment for our FA instance. Today, I receive the above error accompanied by a message “Unable to Authenticate You” in the UI. Access to staging and live environments is unaffected.

I haven’t made any changes locally since being able to access the same environment, yesterday.

Using "forest-express-sequelize": "^8.0.1",

2

I identified the issue in case this helps others in the future.

In Chrome, I had recently enabled “Experimental Web Platform Features.” Disabling this setting in the browser allowed me to access my local FA development environment again.

The setting is located here:
chrome://flags/#enable-experimental-web-platform-features

3

Hey @yeti182 :wave:

I know the thread is marked as resolved, but I would be interested to know which experimental feature you did enable in the experimental chrome settings.
Could you share it here?

Thanks in avdvance :slight_smile:

5

Hi @jeffladiray -

No problem, it was actually just the general Experimental Web Platform features setting listed at the link I included in my post. Here’s a screenshot:

Screen Shot 2022-04-29 at 10.07.23 AM
Screen Shot 2022-04-29 at 10.07.23 AM1330Ă—611 70.7 KB

Hope this helps!

1 Like
6

Hey @yeti182 :wave:

Access-Control-Allow-Private-Network should be handled in the latest release of forest-express-sequelize.

Depending on the type of architecture of your project:

  • If it was generated by lumber/forest-cli you may need to add the following middleware inside app.js 
app.use((req, res, next) => {
  if (req.headers['access-control-request-private-network']) {
    res.setHeader('access-control-allow-private-network', 'true');
  }
  next(null);
});

Must be added right after app.use(morgan('tiny'));

  • If you have an “in-app” installation (Which means you installed forest-express-sequelize inside your existing app) you may only need to upgrade to forest-express-sequelize@8.5.5

A more in-depth thread will be open in the future for this specific error as Chrome will activate this new header in future release.

Let me know if that helps :slight_smile: