[New Data Source]: WAFv2 Managed Rule Version

Description

I would like terraform data sources for versions of Managed WafV2 Rule Groups. Internally, we managed a WAF terraform module which applies several of the Managed rule groups; This will help us identify when these versions change by getting caught in a terraform plan.

The only want to obtain the versions for a managed rule group is via the CLI. AWS provides documentation for setting up notifications (based on a SNS topic). Using either of these to track version changes is a bit cumbersome and requires additional technology outside of terraform. When omitting a version, a "current default" is assumed but the version diff is not see in a terraform plan. This means a terraform plan does not give the full picture of "what changed" which has resulted in some outages in my organization. With a data source we could return an error on plan instead of waiting for an apply for an error, or worse an outage from an unseen change.

I would like to be able to use a data resource for these in two possible scenarios:

Getting current default version for a rule group. This way the data resource is refreshed at play/apply and a proper diff exists to inform us when a version has changed.
Specifying a version for the data source to ensure it is still valid. This could provide a better error back to plans if a specified version does not exist.

These API's exist in the aws-sdk-go-v2 so adding these data sources would be straight forward.

Requested Resource(s) and/or Data Source(s)

aws_wafv2_managed_rule_group_current_default_version
aws_wafv2_managed_rule_group_version

Potential Terraform Configuration

data aws_wafv2_managed_rule_group_current_default_version "latest_version" {
    vendor_name    = "AWS"
    group_name     = "AWSManagedRulesCommonRuleSet"
    scope          = "REGIONAL"
}

data aws_wafv2_managed_rule_group_version "my_pinned_version" {
    vendor_name    = "AWS"
    group_name     = "AWSManagedRulesCommonRuleSet"
    scope          = "REGIONAL"
    version        = "Version_1.7"
}

References

Would you like to implement a fix?

Yes

hashicorp / terraform-provider-aws