aws-elasticache: CfnReplicationGroup cluster mode is missing types

[nickdnk]

Describe the issue

Hello

The clusterMode property of the CfnReplicationGroup component should not be a plain string type, but 'enabled' | 'disabled' | undefined. The documentation (incorrectly?) lists the valid options for this property as Disabled or Enabled, with a capital D/E, which causes problems when you try to deploy, such as incorrectly triggering Cluster mode updates are not supported while attempting to update additional properties. If you instead change to lower-case typing in the CDK, it seems to work as expected. This is described in this thread as well.

So it seems that https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-elasticache-replicationgroup.html#cfn-elasticache-replicationgroup-clustermode is either incorrect or that the output produced by the CDK is different from its input (i.e. lowercase in CDK but titelcase in the API).

Either way, correctly typing this in the CDK would avoid this issue entirely.

Links

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-elasticache-replicationgroup.html#cfn-elasticache-replicationgroup-clustermode

[khushail]

Hi @nickdnk , thanks for reporting this. I checked API reference for ElasticCache, which mentions about ClusterMode values to be with lowercase as this -

ClusterMode

    Enabled or Disabled. To modify cluster mode from Disabled to Enabled, you must first set the cluster mode to Compatible. Compatible mode allows your Valkey or Redis OSS clients to connect using both cluster mode enabled and cluster mode disabled. After you migrate all Valkey or Redis OSS clients to use cluster mode enabled, you can then complete cluster mode configuration and set the cluster mode to Enabled.

    Type: String

    Valid Values: enabled | disabled | compatible

    Required: No

which looks to be different from what's mentioned in Cloudformation docs -

https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.aws_elasticache.CfnReplicationGroup.html#clustermode

IMO, this could be corrected to avoid confusion when setting the values. Since this is reg. the Cfn construct level documentation, this would need to be handled by cloudformation team. I would be filing issue with them and you could track that for updates.

Thanks.

[khushail]

@nickdnk , issue created with Cloudformation team for doc update -aws-cloudformation/cloudformation-coverage-roadmap#2256

[nickdnk]

Hello
Great, thanks.

I would still argue that the type constraint issue belongs in this repo: It should not be a plain string when it only accepts a small set of enumerated values, such as enabled, disabled and compatible.

Edit: Okay, maybe that is already what's happening here. If so, then cool.