Virtual machines templates are an essential tool for IT professionals to quickly deploy infrastructure across multiple platforms. Packer, a product from HashiCorp, is an infrastructure as code tool that helps create consistent and repeatable virtual machine templates. In this series of blog posts, we will explore how to use Packer to deploy virtual machines in vSphere 7.

Packer has several features that make it an attractive choice for virtual machine template management. It supports various source blocks, build blocks, provisioners, and post-processors, which can be used to create a complete configuration for a virtual machine template. Additionally, Packer supports multiple operating systems and has a simple command line interface for building templates.

To get started with Packer, you need to download the executable from the official website. Once downloaded, you need to unzip the file and copy it to either an existing PATH directory or create a new one. For simplicity, we will copy the executable to C:\Windows\System32.

Packer has several installation options, and you can find brief descriptions for each option by running ‘packer’ from the command line. Some of the commonly used options include:

* packer build — This option builds a template using the specified path.

* packer validate — This option validates the template and checks for any errors.

* packer var-file — This option sets a variable file that can be used in your templates.

Packer supports multiple blocks, including source blocks, build blocks, provisioners, and post-processors. Source blocks are used to define the base configuration of your virtual machine template, while build blocks are used to modify the source block and create a complete configuration. Provisioners are used to interface with your template once the operating system is installed, and post-processors are used to run scripts or commands after the build is complete.

Some of the commonly used provisioners include:

* Shell for Linux – This provisioner uses SSH to communicate with the operating system and run scripts or commands.

* PowerShell for Windows – This provisioner uses WinRM to communicate with the operating system and run scripts or commands.

* Windows Update Provisioner – This provisioner installs the latest Windows patches using the Windows Update feature.

There are also several post-processors available, including:

* User-defined variables file (example – variables.pkr.hcl) – This file is used to declare all the variables that you want to reference in your source, build, or provisioner blocks.

* Operating system answer file (example – autounattended.xml) – This file is required to complete the installation of your operating system.

* Scripts and drivers – These are any scripts or drivers that you need to reference in either the answer files or for use by a provisioner.

In conclusion, Packer is an excellent tool for managing virtual machine templates. Its ability to create consistent and repeatable templates across multiple platforms makes it an essential tool for IT professionals. In the next part of this series, we will explore how to create a Windows and Linux template build in further detail.