What did you do to encounter the bug?

Steps to reproduce the behavior:

We use x509 certificates for validation. In the MongoDBCommunity CustomResource, the users are listed under .spec.users without the scramCredentialsSecretName:

- db: $external
    name: CN=user1
    roles:
    - db: admin
      name: clusterAdmin
  - db: $external
    name: CN=user2
    roles:
    - db: db2
      name: readWrite

What did you expect?

No validation errors.

What happened instead?

Errors in the MongoDBCommunity status and in the operator logs:

message: 'error validating new Spec: scram credential secret names collision, update
    at least one of the users: [scram secret name: "" for user: "CN=user1"
    and user: "CN=user2"]

controllers/mongodb_status_options.go:104	error validating new Spec: scram credential secret names collision, update at least one of the users: [scram secret name: "" for user: "CN=user1" and user: "CN=user2"]

Operator Information

• Operator Version - 0.13.0
• MongoDB Image used - 6.0.20

Additional context

Validation was fixed in PR #1597, but according to the documentation, user definitions that use x509 for authentication should not contain scramCredentialsSecretName parameter.

During validation, users without the scramCredentialsSecretName parameter are added to a dictionary with an empty key, which leads to the error mentioned above.

I think we should skip the scram secret collision validation for users authenticated with x509 certificates.