In my previous post I explained the tools I use in my lab automation. Today, we’ll talk about creating Ubuntu templates into VMware vSphere. For this, I will use Packer.
NOTE: You can grab all the files that I’m presenting here from my Github repo:
Some parameters in the public files have been anonymized, please customize the values to suit your needs.
Prepare the system
Before being able to run Packer, I need to create its scripts, but even before I need the data that I will put into the scripts.
Let’s start with the ISO file from where I will install Ubuntu 22.04. I grab the needed Ubuntu ISO and I save it in a vSphere library. I usually get the “live server” version, as it has all the packages available in the ISO. I prefer this method compared to the direct download of live ISO each time I run the script (a common solution that i’ve seen in many similar articles) because it’s faster to run after I only grabbed the ISO once, and it can work also when there is some connectivity issue.
This is the content of my library:
but what I need is its physical path in the underlying datastore, that I can read by browsing the datastore itself:
This information will be passed as a variable in the Packer script, like this:
iso_path = "[vsanDatastore] contentlib-5ed427e9-8cf4-442a-8218-14a8d3cc9dc3/ab0bf964-474e-4e4d-90dd-a324b392d660/ubuntu-22.04.2-live-server-amd64_1641f4b9-dbe1-409a-9433-7cd39c9dbfe7.iso"
I do this because I didn’t find a way to pass the library information to Packer, while I can mount an ISO from a datastore.
Passwords and other data
This is the structure of the files used by Packer:
I need to edit some of them to enter the data I need to customize the VM I will create. Let’s start from top to bottom.
user-data
The user-data file is in the http folder along with an empty file called meta-data. This meta-data file is required for cloud deployments, but since I’m not deploying to the cloud I can leave it empty. But I need to customize the user-data file in some points:
#cloud-config
autoinstall:
version: 1
early-commands:
# workaround to stop ssh for packer as it thinks it timed out
- sudo systemctl stop ssh
locale: en_US
keyboard:
layout: en
variant: us
packages: [open-vm-tools, openssh-server, net-tools, network-manager, perl, open-iscsi, ntp, curl, vim, ifupdown, zip, unzip, gnupg2, software-properties-common, apt-transport-https, ca-certificates, lsb-release, python3-pip, jq, cloud-init]
network:
network:
version: 2
ethernets:
ens192:
dhcp4: true
identity:
hostname: ubuntu2204
username: ubuntu
password: "$6$rounds=4096$pwAk.wxvgujkbm$4x724AhMsslbqtp4dISZppC8sHsNmafcVl.R0B0qZ2q8i2TH4/x4uWfpz1JOX3glSMPo4leBoxn7Oyr62U3In."
ssh:
install-server: yes
allow-pw: yes
authorized-keys:
- ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCb7fcDZfIG+SxuP5UsZaoHPdh9MNxtEL5xRI71hzMS5h4SsZiPGEP4shLcF9YxSncdOJpyOJ6OgumNSFWj2pCd/kqg9wQzk/E1o+FRMbWX5gX8xMzPig8mmKkW5szhnP+yYYYuGUqvTAKX4ua1mQwL6PipWKYJ1huJhgpGHrvSQ6kuywJ23hw4klcaiZKXVYtvTi8pqZHhE5Kx1237a/6GRwnbGLEp0UR2Q/KPf6yRgZIrCdD+AtOznSBsBhf5vqcfnnwEIC/DOnqcOTahBVtFhOKuPSv3bUikAD4Vw7SIRteMltUVkd/O341fx+diKOBY7a8M6pn81HEZEmGsr7rT ubuntu@ubuntu.local
storage:
layout:
name: direct
user-data:
disable_root: false
late-commands:
- echo 'ubuntu ALL=(ALL) NOPASSWD:ALL' > /target/etc/sudoers.d/ubuntu
- curtin in-target --target=/target -- chmod 440 /etc/sudoers.d/ubuntu
As you can read, I configure here the keyboard layout first; then I add the list of the packages I want to automatically install: open-vm-tools are obviously paramount to have the VM be able to use the virtual hardware; openssh-server will be used to connect to the VM from remote and configure it, plus other programs for the networking part and other needs.
For the network, I will use DHCP: there is a way to configure a VM with a static IP, but this is a template so I don’t want to stick with a fixed IP address. Obviously, to create this VM I will need a DHCP server listening on the same portgroup where I will connect this VM.
In the identity section I configure the hostname and I create a default ubuntu user. The password is not written in clear text, but it’s hashed using the following procedure.
I install whois (since mkpasswd is part of this package) and then I input the password so that mkpasswd will return its hash:
sudo apt-get install whois mkpasswd -m sha-512 --rounds=4096
In the authorized-keys section, I can insert my own SSH key that I have in my management Linux machine, the one I’ll use to connect later to the VM. I can create my own SSH key by using:
ssh-keygen
or, if I already have it, I can read it using:
cat ~/.ssh/id_rsa.pub
ubuntu2204.pkr.hcl
This is the main packer file that I will use it to build my machine. There is nothing to configure here. It’s however interesting to notice that user-data is mounted as a cd-rom to be used in the configuration:
cd_files = [
"./${var.http_directory}/meta-data",
"./${var.http_directory}/user-data"]
Also, in the build section I invoke a specific builder for VMware vSphere:
build {
sources = [
"source.vsphere-iso.linux-ubuntu-server"]
vsphere.pkrvars.hcl
This is the file where I store all the vSphere information:
################################################################################## # VARIABLES ################################################################################## # Credentials vcenter_username = "administrator@vsphere.local" vcenter_password = "password" # vSphere Objects vcenter_insecure_connection = true vcenter_server = "vcenter.vsphere.local" vcenter_datacenter = "Datacenter" vcenter_host = "esx.vsphere.local" vcenter_datastore = "vsanDatastore" vcenter_network = "VM Network" vcenter_folder = "Templates" # ISO Objects iso_path = "[vsanDatastore] contentlib-5ed427e9-8cf4-442a-8218-14a8d3cc9dc3/ab0bf964-474e-4e4d-90dd-a324b392d660/ubuntu-22.04.2-live-server-amd64_1641f4b9-dbe1-409a-9433-7cd39c9dbfe7.iso"
Obviously, you will need to adjust these values to be compatible with your own environment.
ubuntu2204.pkrvars.hcl
This is the file where I store all the VM information:
################################################################################## # VARIABLES ################################################################################## # HTTP Settings http_directory = "http" # Virtual Machine Settings vm_name = "ubuntu2204" vm_guest_os_type = "ubuntu64Guest" vm_version = 17 vm_firmware = "bios" vm_cdrom_type = "sata" vm_cpu_sockets = 1 vm_cpu_cores = 2 vm_mem_size = 4096 vm_disk_size = 20480 thin_provision = true disk_eagerly_scrub = false vm_disk_controller_type = ["pvscsi"] vm_network_card = "vmxnet3" vm_boot_wait = "5s" ssh_username = "ubuntu" ssh_password = "ubuntu" # ISO Objects iso_file = "ubuntu-22.04.1-live-server-amd64.iso" iso_checksum = "10f19c5b2b8d6db711582e0e27f5116296c34fe4b313ba45f9b201a5007056cb" iso_checksum_type = "sha256" iso_url = "https://releases.ubuntu.com/jammy/ubuntu-22.04.1-live-server-amd64.iso" # Scripts shell_scripts = ["./scripts/setup_ubuntu2204.sh"]
Here I customize the virtual machine I’m going to build.
Build the VM
I start by initializing the Packer environment:
packer init .
This will verify that the system is ready to execute my scripts; on the first run it will install all the needed additional packages.
Once it’s ready, I start the building script:
packer build -force -on-error=ask -var-file ubuntu2204.pkrvars.hcl -var-file vsphere.pkrvars.hcl ubuntu2204.pkr.hcl
Let’s go grab a coffee, and let Packer work on this:
After a few minutes, if all worked correctly, it should end up with a screen like this:
I have built my new Ubuntu 22.04 template. It took 17 minutes, but I only spent a few seconds running the command, and I’ve used the rest of the time to do something else. And every time I need to update the template, I will just destroy it and build a new one.