[Bug]: Provider tries to update the Knowledge Base when configuration changes which fails with ValidationException

[jammymalina]

Terraform Core Version

1.8.5

AWS Provider Version

5.53.0

Affected Resource(s)

aws_bedrockagent_knowledge_base

Expected Behavior

Terraform should destroy the knowledge base resource (and maybe its dependents) and create it again.

Actual Behavior

Terraform tries to update the knowledge base resource in place and fails with a validation error (status code 400).

Relevant Error/Panic Output Snippet

│ Error: updating Bedrock Agent Knowledge Base (id)
│
│   with module.api.aws_bedrockagent_knowledge_base.kb,
│   on modules/api/main.tf line 292, in resource "aws_bedrockagent_knowledge_base" "kb":
│  292: resource "aws_bedrockagent_knowledge_base" "kb" {
│
│ operation error Bedrock Agent: UpdateKnowledgeBase, https response error StatusCode: 400, RequestID: uuid, ValidationException: You cannot modify the knowledge base configuration once it
│ is created.
╵

Terraform Configuration Files

resource "aws_bedrockagent_knowledge_base" "kb" {
  name     = "${var.resource_prefix}-kb-${var.stage}"
  role_arn = aws_iam_role.kb_role.arn

  storage_configuration {
    type = "OPENSEARCH_SERVERLESS"

    opensearch_serverless_configuration {
      collection_arn    = aws_opensearchserverless_collection.collection.arn
      vector_index_name = var.kb_config.vector_index_name
      field_mapping {
        metadata_field = var.kb_config.metadata_field
        text_field     = var.kb_config.text_field
        vector_field   = var.kb_config.vector_field
      }
    }
  }

  knowledge_base_configuration {
    type = "VECTOR"
    vector_knowledge_base_configuration {
      embedding_model_arn = "arn:${local.aws_partition}:bedrock:${local.region}::${var.kb_config.embedding_model}"
    }
  }

  depends_on = [
    terraform_data.index_creation,
  ]
}

Steps to Reproduce

1. Deploy the knowledge base via Terraform
2. Change the embeddings model and vector size
3. Deploy again

Debug Output

No response

Panic Output

No response

Important Factoids

No response

References

No response

Would you like to implement a fix?

None

[github-actions]

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[acwwat]

@jammymalina Could you please provide the plan output that shows the diff/update?

[acwwat]

Actually, UpdateKnowledgeBase specifies that only name, description, and role ARN can be updated. Anything else should force a new resource creation instead. I think this is enough information to work with.

[github-actions]

Warning

This issue has been closed, meaning that any additional comments are hard for our team to see. Please assume that the maintainers will not see them.

Ongoing conversations amongst community members are welcome, however, the issue will be locked after 30 days. Moving conversations to another venue, such as the AWS Provider forum, is recommended. If you have additional concerns, please open a new issue, referencing this one where needed.

[github-actions]

This functionality has been released in v5.70.0 of the Terraform AWS Provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!

[github-actions]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.
If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.