aws_bedrockagent_agent_alias produces inconsistent result: routing_configuration.agent_version changes from null to string after apply

[cmmo]

Terraform and AWS Provider Version

Terraform Version
  1.11.4

AWS Provider Version
  ~> 6.3

Affected Resource(s) or Data Source(s)

• aws_bedrockagent_agent_alias

Expected Behavior

The provider should not change the agent_version value from null to a string after apply without being
explicitly configured.

Actual Behavior

The provider changes routing_configuration[0].agent_version from null to a string value (e.g., "37", "24")
after apply, causing inconsistent state.

Relevant Error/Panic Output

╷
│ Error: Provider produced inconsistent result after apply
│ 
│ When applying changes to module.aifp_financial_bedrock_agent.aws_bedrockagent_agent_alias.this[0], provider
│ "provider[\"registry.terraform.io/hashicorp/aws\"]" produced an unexpected new value: .routing_configuration[0].agent_version: was null, but now
│ cty.StringVal("37").
│ 
│ This is a bug in the provider, which should be reported in the provider's own issue tracker.
╵
╷
│ Error: Provider produced inconsistent result after apply
│ 
│ When applying changes to module.aifp_general_bedrock_agent.aws_bedrockagent_agent_alias.this[0], provider "provider[\"registry.terraform.io/hashicorp/aws\"]"
│ produced an unexpected new value: .routing_configuration[0].agent_version: was null, but now cty.StringVal("24").
│ 
│ This is a bug in the provider, which should be reported in the provider's own issue tracker.

Sample Terraform Configuration

Click to expand configuration

  resource "aws_bedrockagent_agent_alias" "this" {
    agent_alias_name = "example-alias"
    agent_id         = "AGENT123"
    description      = "Example agent alias"
    
    routing_configuration {
      agent_version = null  # or not specified
    }
  }

Steps to Reproduce

1. Create aws_bedrockagent_agent_alias with routing_configuration.agent_version as null
2. Run terraform apply
3. Observer the inconsistent result error

Debug Logging

Click to expand log output

  Error: Provider produced inconsistent result after apply

  When applying changes to module.aifp_financial_bedrock_agent.aws_bedrockagent_agent_alias.this[0], provider
   "provider[\"registry.terraform.io/hashicorp/aws\"]" produced an unexpected new value:
  .routing_configuration[0].agent_version: was null, but now cty.StringVal("37").

GenAI / LLM Assisted Development

n/a

Important Facts and References

No response

Would you like to implement a fix?

Yes

[github-actions]

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[cmmo]

🔧 Fix Available

This issue has been addressed in PR #43411: #43411

Summary of Changes

The fix addresses the inconsistent result error by properly handling the field in the block:

• Root Cause: The provider was not correctly handling the transition between null and string values for
• Solution: Enhanced the flattening logic to maintain consistency between planned and actual state
• Testing: Added comprehensive test coverage for both scenarios (null and explicit values)

Files Changed

• internal/service/bedrockagent/agent_alias.go - Fixed inconsistent result handling
• internal/service/bedrockagent/agent_alias_test.go - Added test coverage
• .changelog/43411.txt - Added changelog entry

The fix maintains backward compatibility and follows HashiCorp's contribution guidelines.