This document introduces Packer, an open source tool for building machine images for multiple platforms. Packer builds images from templates defined in code using HashiCorp Configuration Language. Templates include variables, sources, builds, provisioners, and post-processors. Packer supports building images for platforms like VMware, AWS, Azure, and Docker. The document provides examples of Packer templates and processes for building images.

1. AUTOMATE
BUILDING YOUR VM
TEMPLATES WITH
PACKER

2. WHAT IS
PACKER?
 A free, open source tool for creating machine images
for multiple platforms
 Cross-platform – run from Windows, Mac, or Linux
 Image builds are defined in code, using the
HashiCorp configuration language (HCL) or JSON
(old way)
 Plugins to support building images for many
platforms like vSphere, AWS, Azure, Docker, and
more
 “Provisioners” like shell scripts, Ansible, Salt, and
more to configure your images

3. WHY?
 Consistency – get the same result every time
 Images as code – easier to document, version
control (history!), and automate
 Create identical images across environments –
vSphere, Workstation/Fusion, public clouds, etc.
 No more monthly “convert to VM, boot up, install
updates, shut down, convert to template” cycle –
just rebuild!

4. ANATOMY OF A PACKER TEMPLATE (HCL) - BLOCKS
packer – Packer settings and required plugins
variable – configuration for variables which can be set at runtime
locals – variables created within the template, using functions or composited from other variables
data – defines data sources to fetch data from outside Packer
source – configuration for builder plugins; used by the build block
build – configuration for a combination of builders, provisioners, and post-processors that create a specific image
provisioner – configuration for provisioner plugins – these run after the image is booted
post-processor – configuration for post-processor plugins; these run after the build

5. VARIABLES
 Define variables in the variable and/or local blocks
 Assign values:
 Defaults (in code)
 .pkrvars.hcl file
 -var-file="testing.pkrvars.hcl"
 .auto.pkrvars.hcl file
 Command line
 -var "name1=value1“ -var "name2=value2"
https://www.packer.io/docs/templates/hcl_templates/variables

6. SOURCE BLOCK
 Contains the configuration for builder plugins
 Tells Packer where and how to boot your image
 Settings depend on the builder
 Could have more than one in a template
 Referred to by the build block
https://www.packer.io/docs/templates/hcl_templates/blocks/source

7. BUILD BLOCK
 Defines what builders are started
 Includes provision blocks (optional)
 How to customize images
 Includes post-processor blocks (optional)
 What do to with output artifacts (images)
https://www.packer.io/docs/templates/hcl_templates/blocks/build

8. PROVISIONERS AND
POST-PROCESSORS
 Provisioners run during the build – after the source image boots up
 Post-processors run after the build – can act on the resulting image

9. VMWARE BUILDERS
VMware Workstation Builders
 Build locally in VMware Workstation or Fusion
 Creates a VM (vmx/vmdk files) or OVF/OVA
 vmware-iso – starts from scratch (ISO file)
 vmware-vmx – starts from an existing VM (vmx)
vSphere Builders
 Build on a vCenter Server or ESXi host
 Creates a VM or template, optionally export to OVF
 vsphere-iso – starts from scratch (ISO file)
 vsphere-clone – starts from an existing VM or
template
 Can work with clusters or standalone hosts
 Options to export to a Content Library

10. PROCESS
 packer init TEMPLATE
 Install plugins
 packer validate TEMPLATE
 Make sure syntax is OK
 packer fmt TEMPLATE
 (optional) Format your code
 packer build TEMPLATE
 packer build –var-file=my.pkrvars.hcl TEMPLATE
 packer build –var "foo=bar" –var "foo2=bar2" TEMPLATE

11. https://github.com/danbarr/packer-example

12. RESOURCE:
EXAMPLE
VSPHERE
TEMPLATES
https://github.com/vmware-samples/packer-examples-for-vsphere
 Excellent collection of Packer templates for many operating
systems
 Great examples to use as-is, or to get ideas on how to use
Packer

13. RESOURCES
 Download - https://www.packer.io/downloads
 Tutorials - https://learn.hashicorp.com/packer
 Documentation - https://www.packer.io/docs