[terraform] Update retry logic to handle DNS-related errors more gracefully

[Alexander Smolyakov (alexander-smolyakov)]

Feature name:

• ghcr.io/devcontainers/features/terraform

Description:

This PR aims to update the retry logic to handle the gpg: keyserver receive failed: Server indicated a failure error more gracefully.

The gpg returns the keyserver receive failed: Server indicated a failure error if something goes wrong with DNS-related stuff. It looks like gpg could use several libraries for working with DNS servers based on macros values. Related code:

• https://github.com/gpg/libgpg-error/blob/master/src/err-codes.h.in#L253
• https://github.com/gpg/gnupg/blob/master/dirmngr/dns-stuff.c#L1610

This means that gpg could work with DNS servers differently than other tools.

The fix is to try to get the IP address of the GPG keyserver and explicitly pass it to the gpg tool to avoid DNS-related issues.

Changelog:

• Retry logic updated: Additional tries with explicitly passing the keyserver IP address were added;
• Thednsutils package added to dependencies;

Attached related issue:

• Terraform devcontainer feature v1.3.4 gpg error #686

Checklist:

• Checked that applied changes work as expected

[Samruddhi Khandale (samruddhikhandale)]

Looks good, thank you! 🎉