Install IPI cluster where all nodes are provisioned from azure marketplace image with purchase plan.

install-config.yaml:
---------------------------
platform:
  azure:
    region: eastus
    baseDomainResourceGroupName: os4-common
    defaultMachinePlatform:
      osImage:
        publisher: Redhat  <----  contains uppercase letter
        offer: rh-ocp-worker
        sku: rh-ocp-worker
        version: 4.8.2021122100
        plan: WithPurchasePlan

as some marketplace images are free without plan, so pulisher in install-config should come from output of `az vm image list`

# az vm image list --offer rh-ocp-worker --all -otable
Architecture    Offer          Publisher       Sku                 Urn                                                             Version
--------------  -------------  --------------  ------------------  --------------------------------------------------------------  --------------
x64             rh-ocp-worker  redhat-limited  rh-ocp-worker       redhat-limited:rh-ocp-worker:rh-ocp-worker:4.8.2021122100       4.8.2021122100
x64             rh-ocp-worker  RedHat          rh-ocp-worker       RedHat:rh-ocp-worker:rh-ocp-worker:4.8.2021122100               4.8.2021122100
x64             rh-ocp-worker  redhat-limited  rh-ocp-worker-gen1  redhat-limited:rh-ocp-worker:rh-ocp-worker-gen1:4.8.2021122100  4.8.2021122100
x64             rh-ocp-worker  RedHat          rh-ocp-worker-gen1  RedHat:rh-ocp-worker:rh-ocp-worker-gen1:4.8.2021122100          4.8.2021122100

the image plan is as below, its publisher is lowercase.
# az vm image show --urn RedHat:rh-ocp-worker:rh-ocp-worker:4.8.2021122100 --query plan
{
  "name": "rh-ocp-worker",
  "product": "rh-ocp-worker",
  "publisher": "redhat"
}

From installer https://github.com/openshift/installer/blob/master/data/data/azure/bootstrap/main.tf#L243-L246, publisher property in image plan is from pulisher what we set in install-config.yaml, installer should use the publisher property from image plan output.

But image plan is case-sensitive, bootstrap instance is provisioned failed with below error in such case.

Unable to deploy from the Marketplace image or a custom image sourced from Marketplace image. The part number in the purchase information for VM '/subscriptions/53b8f551-f0fc-4bea-8cba-6d1fefd54c8a/resourceGroups/jima15image1-flg24-rg/providers/Microsoft.Compute/virtualMachines/jima15image1-flg24-bootstrap' is not as expected. Beware that the Plan object's properties are case-sensitive. Learn more about common virtual machine error codes.

similar errors when provisioning worker instances from this image where image publisher contains upper case but publisher in its plan is all lowercase.

worker machineset:
----------------------------
Spec:
  Lifecycle Hooks:
  Metadata:
  Provider ID:  azure:///subscriptions/53b8f551-f0fc-4bea-8cba-6d1fefd54c8a/resourceGroups/ci-op-cc5g2rw8-55267-q66k7-rg/providers/Microsoft.Compute/virtualMachines/ci-op-cc5g2rw8-55267-q66k7-worker-southcentralus1-dq6sp
  Provider Spec:
    Value:
      Accelerated Networking:  true
      API Version:             machine.openshift.io/v1beta1
      Credentials Secret:
        Name:       azure-cloud-credentials
        Namespace:  openshift-machine-api
      Diagnostics:
        Boot:
          Storage Account Type:  AzureManaged
      Image:
        Offer:           rh-ocp-worker
        Publisher:       RedHat
        Resource ID:     
        Sku:             rh-ocp-worker
        Type:            WithPurchasePlan
        Version:         4.8.2021122100
      Kind:              AzureMachineProviderSpec
      Location:          southcentralus
      Managed Identity:  ci-op-cc5g2rw8-55267-q66k7-identity

error when provision worker instance:
Unable to deploy from the Marketplace image or a custom image sourced from Marketplace image. The part number in the purchase information for VM '/subscriptions/53b8f551-f0fc-4bea-8cba-6d1fefd54c8a/resourceGroups/ci-op-cc5g2rw8-55267-q66k7-rg/providers/Microsoft.Compute/virtualMachines/ci-op-cc5g2rw8-55267-q66k7-worker-southcentralus1-mmr2h' is not as expected. Beware that the Plan object's properties are case-sensitive. Learn more about common virtual machine error codes.

4.14.0-0.nightly-2023-08-11-055332

Always on 4.14 for bootstrap/masters
Always on 4.11+ for workers

1. Config osImage for all nodes in install-config, set publisher to RedHat 
2. install cluster.
3.

Bootstrap instance is provisioned failed.

installation is successful.

Installation is successful when setting publisher to "redhat"