Credentials check fails when using VPC Service Controls

[leg100]

I tried using gcsfs on a VM, using its metadata credentials, in a project contained within a VPC service perimeter. gcsfs successfully fetches the credentials, but when it then goes onto check the credentials by accessing a public GCS bucket, it fails because the perimeter blocks access to Google APIs for other projects.

I'm aware you can disable the check, but this isn't straightforward in my case, because I'm using pandas and it doesn't expose the relevant parameter that disables the check.

This may well trip other users using VPC service controls.

[martindurant]

The check should probably be omitted by default. Would you like to make the appropriate change in a PR?