DevOps Classroom Series – 23/Oct/2020

Packer

• Is an Opensource tool for creating virtual machine images for multiple platforms from a single configuration
• For the scenario below
• From one configuration file we can create multiple vm images in different cloud /virtual platforms
• Lets install packer.
  • Windows:
    • Download the installable and install Refer Here
    • Use chocolatey to install packer choco install packer
  • Linux Machine: Download packer and add the executable to PATH
• Packer configurations are written in json files
• In Packer we write the template in Json Format. Refer Here for official docs
• Packer template has the following structure

{
    "variables": {},
    "builders": [],
    "description": "",
    "provisioners": [],
    "post-processors" : []
}

• Variable: This is input that can be passed by the user

• builders:

  • This is required object
  • This is array of one or more objects
  • Each builder gives information to packer on where to create machine image
  • Refer Here for builders

• provisioners:

  • For configuring software we would be using provisioners

• post-processors

  • This is array of objects for post-processing

• Manual Steps:

  • Lets create an ami with nginx installed
    • Create an ec2 instance
    • Install the software by logging in

    sudo apt update
    sudo apt install nginx -y
    

    • Create an amazon machine image
    • Lets use packer to create nginx image
    • For amazon-ebs builder Refer Here
    • For Variables Refer Here
    • For Provisioners Refer Here
    • In this example we would be using shell provisioner
    • Refer Here for the changes
    • Execute packer build command and wait for the ami’s to be created

• Try to create nginx vm image on azure by following the documentation. Refer Here