Automating a RHEL 8 Installation Using the VMware REST Ansible Collection

Managing virtual machines in an IT infrastructure is often a common task, specifically VMware virtualization technology has been around for over 20 years. VMware administrators spend a lot of their time in automating the creation, management, and removal of virtual instances that contain various operating systems. One operating system that often resides on VMware infrastructure is Red Hat Enterprise Linux.

With the introduction of VMware REST APIs, we recently announced the initial release of the vmware.vmware_rest Collection, for production use. As opposed to the community.vmware Collection, the vmware.vmware_rest Collection is based on next generation VMware REST APIs. This new Collection no longer requires any third party Python bindings to communicate with VMware infrastructure. A large part of the new Collection that has been introduced is support for automating virtual machine operations.

In this blog post I will show you how VMware users can automate the installation of Red Hat Enterprise Linux 8 (RHEL 8) using the vmware.vmware_rest.vcenter_vm module and a valid Kickstart file.

Scenario requirements

For this scenario, we will assume following requirements:

vCenter 7.0.1 or latest with at least one ESXi
RHEL 8 installation DVD
Ansible
vmware.vmware_rest collection installed with latest version

Preparing Installation ISO file

We will be automating RHEL 8 installation using the Kickstart file fetched via iso image file. We will not discuss Kickstart file creation and management as this has already been covered in the documentation. You might want to visit Kickstart Info Access Labs to refresh your knowledge.

Gathering information about infrastructure

We will use environment variables to specify VMware credentials. This will make playbooks short and tidy. In order to do this, you need specify following environment variables:

VMWARE_HOST
VMWARE_USER
VMWARE_PASSWORD
VMWARE_VALIDATE_CERTS

Let us now start with our playbook which will create the virtual machine in vCenter. All modules in vmware.vmware_rest Collection use VMware managed object ID (MoID) for identifying and referencing VMware objects. The MoIDs are unique in the given vCenter so there is no need to specify names and folders.

We need to provide information where the virtual machine is going to be placed. This information comprises MoIDs of cluster, datastore, folder and resource pool. We can use existing modules from vmware.vmware_rest Collection to collect this information.

- name: Get Cluster info
   vmware.vmware_rest.vcenter_cluster_info:
         filter_names:
         - "{{ cluster_name }}"
   register: cluster_info

 - name: Get Resource info for {{ cluster_name }}
   vmware.vmware_rest.vcenter_cluster_info:
         cluster: "{{ cluster_info.value[0].cluster }}"
   register: resource_pool_info

 - name: Get datastore info
   vmware.vmware_rest.vcenter_datastore_info:
         filter_names:
         - "{{ datastore_name }}"
   register: datastore_info

 - name: Get folder info
   vmware.vmware_rest.vcenter_folder_info:
         filter_names:
         - '{{ folder_name }}'
   register: folder_info

We will need information about the standard portgroup to which the virtual machine is going to be attached to. Gathering information about the MoID of a standard portgroup can be done using vmware.vmware_rest.vcenter_network_info module.

- name: Get a list of the networks with a filter
vmware.vmware_rest.vcenter_network_info:
      filter_types: STANDARD_PORTGROUP
      filter_names:
      - "VM Network"
register: network_info

Creating a virtual machine

Once we have all the information required for create a virtual machine, let us move on to the module which creates the virtual machine that is vcenter_vm:

- name: Create a VM
  vmware.vmware_rest.vcenter_vm:
      boot:
      delay: 0
      enter_setup_mode: false
      retry: false
      retry_delay: 10000
      type: "BIOS"
      boot_devices: []
      cdroms:
      - allow_guest_control: true
        backing:
          type: "ISO_FILE"
          iso_file: "[ds_200] iso/rhel_8.3_ks.iso"
        ide:
          master: true
          primary: true
        label: "CD/DVD drive 1"
        start_connected: true
        type: "IDE"
      cpu:
      cores_per_socket: 1
      count: 1
      hot_add_enabled: false
      hot_remove_enabled: false
      disks:
      - new_vmdk:
           capacity: 536870912
        label: "Hard disk 1"
        scsi:
          bus: 0
          unit: 0
        type: "SCSI"
      guest_OS: "OTHER_LINUX_64"
      hardware_version: "VMX_13"
      memory:
      hot_add_enabled: true
      size_MiB: 4096
      name: test_vm_3
      nics:
      - start_connected: true
        type: VMXNET3
          mac_type: GENERATED
          backing:
            type: STANDARD_PORTGROUP
            network: "{{ network_id }}"
      scsi_adapters:
      - label: "SCSI controller 0"
        scsi:
          bus: 0
          unit: 7
        sharing: "NONE"
        type: "PVSCSI"
      placement:
       datastore: '{{ datastore_id }}'
       folder: '{{ folder_id }}'
       resource_pool: '{{ resource_pool_id }}'
  register: vm_info

Here, we specified to create a virtual machine with 4 GB memory with 1 single NIC attached to "VM network". Additionally, we attached a CDROM to this virtual machine for installation DVD with kickstart file inside it.

You can power on the virtual machine using following tasks:

- name: Turn the power-on the VM
   vmware.vmware_rest.vcenter_vm_power:
         state: start
         vm: '{{ vm_info.id }}'

After powering on the virtual machine, installation will start as default option with the given kickstart file:

rhel blog one

Boot menu with Kickstart file as default option

rhel blog two

Linux Kernel boot parameters

It will take some time to install the new operating system, depending upon the configurations. You can mark this newly installed virtual machine as a template and can use it for clone operation.

Conclusion & Where to go next

Combining this Collection with vmware.vmware_rest, Ansible users can better manage virtual instances on VMware infrastructure with faster iterations and easier maintenance.

Ansible lets you connect the different technologies with your VMware infrastructure that are ultimately needed to be successful in your efforts.

The Collection vmware.vmware_rest is a solid foundation for VMware automation, which is coming in the near future. We're always looking to improve to help users like you get things done in more simplified, faster ways.