Update SDK and make machine pool cloud_credential_secret_name optional to fix plan bug

[a-blender]

Issue:

#835

Problem

When creating an RKE2 cluster via Terraform on any hosted provider (Amazon EC2, Azure, Linode driver so far), Terraform computes a new value for a duplicate field cloud_credential_secret_name in the machine pool and then throws an error on a terraform apply pertaining to that new value. It works on a second run of terraform apply but is frustrating and widely seen by many customers.

Solution

That field currently exists in both rancher_cluster_v2 and rancher_cluster_v2.machine_pool. I couldn't find docs on why the cloud credential secret was added to the machine pool. Rancher pulls the cloud credential secret from the RKECommonNodeConfig and sets it on the newly created machine here as well as the cluster management Spec but doesn't do anything further with it. This looks like a legacy-related change from this PR but I don't fully know the context of the design decision here.

Rancher allows you to mix and match secrets, possibly to support the use case where a customer has machine pools in separate AWS/cloud accounts. The TF provider rancher2 must have parity with Rancher so this field cannot be removed (as I originally thought) because that would cause a regression.

Update 2/10: I believe this is a bug/compatibility issue in the Terraform plugin SDK. See comment #835 (comment) for further details.

This PR has the following fix

• Update machine_pool.cloud_credential_secret_name to be Optional. This keeps parity with Terraform and fixes the plan bug
• Update docs
• Update Terraform plugin SDK to 1.17.2

Testing

Engineering Testing

Manual Testing

Tested with RKE2 clusters on Amazon EC2. Each cluster provisions successfully on the first try of terraform apply. If you do not specify a cloud credential, the cluster hangs with Waiting for viable init node trying to create the machine. I am open to discussion on this behavior.

Testing

• only machine_pool.cloud_credential_secret_name
• only global cloud_credential_secret_name
• both global cloud_credential_secret_name and machine_pool.cloud_credential_secret_name
• no cc (cannot create nodes as expected)

[HarrisonWAffel]

The code change looks fine, though the PR description talks about docs updates which I don't see yet