Add Support for Reading Credentials from KMS Secrets

[osterman]

what

resource "aws_rds_cluster" "example" {
  # ... other configuration ...
  master_password = "${data.aws_kms_secrets.example.plaintext["master_password"]}"
  master_username = "${data.aws_kms_secrets.example.plaintext["master_username"]}"
}

why

• More secure. No passwords in terraform statefile.

references

https://www.terraform.io/docs/providers/aws/d/kms_secrets.html

[sebastianmacarescu]

I think we can also add support for SecretsManager or ParameterStore.
If the maintainers agree I could make a PR to support 2 new parameters: admin_user_ssm_path and admin_password_ssm_path

[zwass]

Even if you just allowed the master password to be managed separately (as though it were in a lifecycle ignore_changes) block that would be sufficient for my use case. As it stands this seems terribly insecure.

[nitrocode]

At the moment, we use random provider to create the master password which is stored in SSM and then the value is fed to this module.

[rstml]

This is now natively supported by RDS and Terraform provider. I think this issue can be closed in favour of #166

https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/rds_cluster#rdsaurora-managed-master-passwords-via-secrets-manager-default-kms-key