Introduction
Terraform CLI users before v0.11.15 can have issues with using new providers.
terraform init stops with the error message Error installing provider "external": openpgp: signature made by unknown entity .
Problem description
Allowed list of Terraform providers OpenPGP signatures for Terraform was changed.
Terraform versions before v0.11.15 don't accept new signatures and throw an error message.
terraform init is downloading the latest external provider binary but a new signature is accepted only after terraform version v0.11.15.
Solution
It's not possible to use newer providers with Terraform CLI version that is "End of Life".
In order to make terraform init work you should downgrade the provider version to one that had an older signature and was accepted by Terraform before v0.11.15.
For example, provider external downgrade would look like the following:
provider "external" {
version "< 2.1.0"
}
Additional notes
The current solution is dedicated to quick-fix terraform code that broke.
Please upgrade your code and Terraform CLI to a recent version.
Using 'End Of Life' Terraform CLI and outdated providers can lead to unexpected run results.