[Bug]: Terraform does not detect that auto_minor_version_upgrade was changed manually via AWS Console

[EugenKon]

Terraform Core Version

1.10.5

AWS Provider Version

5.84.0

Affected Resource(s)

• aws_elasticache_replication_group

Expected Behavior

I changed option via AWS Console manually

Apply changes on the next page.

Then I want to revert back this change via terraform plan/apply.

Terraform should detect that the option was changed in AWS Console. And revert it back to true value.

https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/elasticache_replication_group#auto_minor_version_upgrade-1

Actual Behavior

Nothing had happened.

Relevant Error/Panic Output Snippet

Terraform Configuration Files

resource "aws_elasticache_replication_group" "redis" {
  replication_group_id = "${var.project_name}-redis"
  description          = "Redis cluster for iGuide application"
  subnet_group_name    = aws_elasticache_subnet_group.redis.name
  security_group_ids   = [aws_security_group.redis.id]

  node_type            = "cache.t3.micro"
  port                 = 6379
  engine               = "redis"
  engine_version       = "7.1"
  parameter_group_name = "default.redis7"

  cluster_mode               = "disabled"
  automatic_failover_enabled = false
  num_cache_clusters         = 1

  at_rest_encryption_enabled = false
  transit_encryption_enabled = false

  snapshot_retention_limit = 5
  snapshot_window          = "03:00-04:00"
}

Steps to Reproduce

1. Create Redis replication group
2. Turn off auto upgrades via AWS Console
3. terraform plan/apply

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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[justinretzolk]

Hey @EugenKon 👋 Thank you for taking the time to raise this! I notice that in your example Terraform configuration, you don't have apply_immediately set. Frankly, I can't recall (or immediately locate documentation around) whether changing the status of auto_minor_version_upgrade is something that's applied immediately regardless, or if that changes on the next maintenance window as well. Did you happen to wait until after the next maintenance window to test the next terraform plan?

It may also be worth using the aws CLI or API directly to describe the cache cluster and see what the upstream API is returning. You could also see this using Terraform's debug logging, but there's obviously a bit more noise to dig through that way.

[EugenKon]

I used apply immediately when changed the option via AWS Console.

Thus on the cluster we have false value instantly and at TF state I have false. Thus TF should show the difference.