Support Opentofu iterated provider

[dene14]

Pull Request

The fix allows terragrunt-atlantis-config to work with OpenTofu's iterated provider definitions, enabling multi-region resource provisioning as requested.

Related Github Issues

407

Description

Solution includes:

1. New OpenTofu-aware parsing module (cmd/parse_opentofu.go):
   • parseOpenTofuProviderRef() - Handles OpenTofu provider syntax with index operations
   • parseTerraformLocalModuleSourceOpenTofu() - Fallback parser when standard parsing fails
   • isOpenTofuProviderSyntax() - Detects OpenTofu provider patterns
2. Modified existing parsing logic (cmd/parse_tf.go):
   • Updated parseTerraformLocalModuleSource() to try OpenTofu-aware parsing first
   • Falls back to standard parsing if OpenTofu parsing fails
   • Maintains backward compatibility
3. Test cases and validation:
   • Created test example with OpenTofu provider syntax
   • Added TestOpenTofuProviderSyntax test case
   • Generated golden test file for validation
   • Updated affected golden files

Key Features of the Fix

• Backward Compatible: Existing Terraform configurations continue to work unchanged
• OpenTofu Support: Now handles syntax like aws.by_region[each.key]
• Graceful Fallback: If OpenTofu parsing fails, falls back to standard parsing
• Comprehensive Testing: Includes test cases and validation

Legend for modified files

cmd/parse_opentofu.go - New OpenTofu parsing module
cmd/parse_tf.go - Updated to use OpenTofu-aware parsing
cmd/generate_test.go - Added test case
cmd/golden/opentofu_provider_syntax.yaml - Golden test file
cmd/golden/envhcl_allchilds.yaml - Updated to include new test case

Test Results

✅ The OpenTofu provider syntax now works without errors
✅ All existing functionality remains intact
✅ Test cases pass successfully

Security Implications

• [none]

System Availability

• [none]

[dene14]

@dmattia can we get this reviewed/merged?

[dene14]

@dennislapchenko just in case also ping you