The configuration values of the CPMS generated by installer on vSphere is not the same with the configuration values of the master machines, although it doesn’t trigger update when installing the cluster with TechPreview, but it’s confusing for users. 

Another, if installing a cluster without TechPreview, then enable TechPreview for day2 operation, the CPMS is inactive by default, then only active CPMS and do not change other configuration values, it will trigger update, this is not as expected.

Also, on other providers(AWS, GCP, Azure, Nutanix), the configuration values of the CPMS generated by installer is the same with the configuration values of the master machines.    

4.15.0-0.nightly-2023-12-04-223539

Always 

1.Create a cluster on vSphere with TechPreview, we use flexy-template: ipi-on-vsphere/versioned-installer_techpreview, there is CPMS by default and it’s Active.  
liuhuali@Lius-MacBook-Pro huali-test % oc get clusterversion
NAME      VERSION                              AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.15.0-0.nightly-2023-12-04-223539   True        False         6m1s    Cluster version is 4.15.0-0.nightly-2023-12-04-223539
liuhuali@Lius-MacBook-Pro huali-test % oc project openshift-machine-api
Already on project "openshift-machine-api" on server "https://api.huliu-vs07b.qe.devcluster.openshift.com:6443".
liuhuali@Lius-MacBook-Pro huali-test % oc get machine
NAME                               PHASE     TYPE   REGION   ZONE   AGE
huliu-vs07b-pkm69-master-0         Running                          27m
huliu-vs07b-pkm69-master-1         Running                          27m
huliu-vs07b-pkm69-master-2         Running                          27m
huliu-vs07b-pkm69-worker-0-5cgd9   Running                          21m
huliu-vs07b-pkm69-worker-0-ql9zv   Running                          21m
liuhuali@Lius-MacBook-Pro huali-test % oc get controlplanemachineset
NAME      DESIRED   CURRENT   READY   UPDATED   UNAVAILABLE   STATE    AGE
cluster   3         3         3       3                       Active   27m   

2.Check the configuration values in CPMS is not the same with the master machines. But they should be the same.
liuhuali@Lius-MacBook-Pro huali-test % oc get controlplanemachineset cluster -oyaml
…
        providerSpec:
          value:
            apiVersion: machine.openshift.io/v1beta1
            credentialsSecret:
              name: vsphere-cloud-credentials
            diskGiB: 120
            kind: VSphereMachineProviderSpec
            memoryMiB: 16384
            metadata:
              creationTimestamp: null
            network:
              devices: null
            numCPUs: 4
            numCoresPerSocket: 4
            snapshot: ""
            template: ""
            userDataSecret:
              name: master-user-data
            workspace: {}
…
liuhuali@Lius-MacBook-Pro huali-test % oc get machine huliu-vs07b-pkm69-master-2  -oyaml
…
  providerSpec:
    value:
      apiVersion: machine.openshift.io/v1beta1
      credentialsSecret:
        name: vsphere-cloud-credentials
      diskGiB: 120
      kind: VSphereMachineProviderSpec
      memoryMiB: 16384
      metadata:
        creationTimestamp: null
      network:
        devices:
        - networkName: devqe-segment-221
      numCPUs: 4
      numCoresPerSocket: 4
      snapshot: ""
      template: huliu-vs07b-pkm69-rhcos-generated-region-generated-zone
      userDataSecret:
        name: master-user-data
      workspace:
        datacenter: DEVQEdatacenter
        datastore: /DEVQEdatacenter/datastore/vsanDatastore
        folder: /DEVQEdatacenter/vm/huliu-vs07b-pkm69
        resourcePool: /DEVQEdatacenter/host/DEVQEcluster//Resources
        server: vcenter.devqe.ibmc.devcluster.openshift.com
…

Must-gather: https://drive.google.com/file/d/1KC4fwvQudRRebi9DyNOVtRT2AmenL5ek/view?usp=sharing 

3.Install a cluster on vSphere without TechPreview, we use flexy-template: ipi-on-vsphere/versioned-installer, there is no CPMS by default. 
liuhuali@Lius-MacBook-Pro huali-test % oc get clusterversion                                                      
NAME      VERSION                              AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.15.0-0.nightly-2023-12-04-223539   True        False         16m     Cluster version is 4.15.0-0.nightly-2023-12-04-223539
liuhuali@Lius-MacBook-Pro huali-test % oc project openshift-machine-api
Now using project "openshift-machine-api" on server "https://api.huliu-vs07c.qe.devcluster.openshift.com:6443".
liuhuali@Lius-MacBook-Pro huali-test % oc get machine
NAME                               PHASE     TYPE   REGION   ZONE   AGE
huliu-vs07c-p6258-master-0         Running                          41m
huliu-vs07c-p6258-master-1         Running                          41m
huliu-vs07c-p6258-master-2         Running                          41m
huliu-vs07c-p6258-worker-0-78zxg   Running                          36m
huliu-vs07c-p6258-worker-0-tv2rw   Running                          36m
liuhuali@Lius-MacBook-Pro huali-test % oc get controlplanemachineset
No resources found in openshift-machine-api namespace.

4.Enable TechPreview, there is CPMS now, and it’s Inactive
liuhuali@Lius-MacBook-Pro huali-test % oc edit featuregate                                            
featuregate.config.openshift.io/cluster edited
liuhuali@Lius-MacBook-Pro huali-test % oc get controlplanemachineset
NAME      DESIRED   CURRENT   READY   UPDATED   UNAVAILABLE   STATE      AGE
cluster   3         3         3                               Inactive   13m
liuhuali@Lius-MacBook-Pro huali-test % oc get controlplanemachineset cluster -oyaml
…
        providerSpec:
          value:
            apiVersion: machine.openshift.io/v1beta1
            credentialsSecret:
              name: vsphere-cloud-credentials
            diskGiB: 120
            kind: VSphereMachineProviderSpec
            memoryMiB: 16384
            metadata:
              creationTimestamp: null
            network:
              devices: null
            numCPUs: 4
            numCoresPerSocket: 4
            snapshot: ""
            template: ""
            userDataSecret:
              name: master-user-data
            workspace: {}

5.Edit the CPMS, only change Inactive to Active. It triggers update, but it shouldn’t, because I didn’t change any configuration values.

liuhuali@Lius-MacBook-Pro huali-test % oc edit controlplanemachineset                             
controlplanemachineset.machine.openshift.io/cluster edited
liuhuali@Lius-MacBook-Pro huali-test % oc get machine
NAME                               PHASE          TYPE   REGION   ZONE   AGE
huliu-vs07c-p6258-master-0         Running                               59m
huliu-vs07c-p6258-master-1         Running                               59m
huliu-vs07c-p6258-master-2         Running                               59m
huliu-vs07c-p6258-master-ccgth-0   Provisioning                          8s
huliu-vs07c-p6258-worker-0-78zxg   Running                               54m
huliu-vs07c-p6258-worker-0-tv2rw   Running                               54m
liuhuali@Lius-MacBook-Pro huali-test % oc logs control-plane-machine-set-operator-85595cdfdf-zh9bk
…
I1207 08:59:32.993680       1 updates.go:473]  "msg"="Machine requires an update" "controller"="controlplanemachineset" "diff"=["Template: /DEVQEdatacenter/vm/huliu-vs07c-p6258/huliu-vs07c-p6258-rhcos-generated-region-generated-zone != huliu-vs07c-p6258-rhcos-generated-region-generated-zone"] "index"=2 "name"="huliu-vs07c-p6258-master-2" "namespace"="openshift-machine-api" "reconcileID"="da8e7371-8378-42df-8a41-bc3f4198fb20" "updateStrategy"="RollingUpdate"


Must gather: https://drive.google.com/file/d/1LL_anFTNsH5O4cIJSUzioyHphS_avyTP/view?usp=sharing 

The configuration values of the CPMS generated by installer on vSphere is not the same with the configuration values of the master machines

The configuration values of the CPMS generated by installer on vSphere should be the same with the configuration values of the master machines