Install Packer

https://learn.hashicorp.com/tutorials/packer/get-started-install-cli?in=packer/aws-get-started

curl -fsSL https://apt.releases.hashicorp.com/gpg | sudo apt-key add -
sudo apt-add-repository "deb [arch=amd64] https://apt.releases.hashicorp.com $(lsb_release -cs) main"
sudo apt-get update && sudo apt-get install packer

To verify installation just type packer in the terminal

packer
Usage: packer [--version] [--help] <command> [<args>]

Available commands are:
    build           build image(s) from template
    console         creates a console for testing variable interpolation
    fix             fixes templates from old versions of packer
    fmt             Rewrites HCL2 config files to canonical format
    hcl2_upgrade    transform a JSON template into an HCL2 configuration
    init            Install missing plugins or upgrade plugins
    inspect         see components of a template
    validate        check that a template is valid
    version         Prints the Packer version

Working with Packer

The Packer builds images by using the provided .hcl or .json dodcument. For this tutorial we are going to use the former. To start, create the directory where you will work and navigate into it

mkdir packer_dir
cd packer_dir

Place the provide aws-ubuntu.pkr.hcl document inside of it The document contains multiple blocks, here is the brief description of each

1. packer block contains the information about the version of Packer to use as well as the plugins needed to create the image in the required_plugins section. In this case the plugin we need is amazon . Some of these plugins, like the Amazon AMI Builder (AMI builder) which you will to use, are built, maintained, and distributed by HashiCorp — but anyone can write and use plugins.

2. variable block contains the variable definition. In this case, the variables are used for AMI name. There are multiple ways to assign variables which include variable file(s) and command-line flag. It will be shown in the later part of the tutorial

3. source block configures a specific builder plugin, which is then invoked by a build block. A source block has two important labels: a builder type and a name. These two labels together will allow us to uniquely reference sources later on when we define build runs. In the example template, the builder type is amazon-ebs and the name is ubuntu. We declare the name of the created AMI using the previously declared variables, the region and the instance type which will be used during the building process. launch_block_device_mappings is used to either modify or to add additional volume mounts to the instance. In this case we modify the root volume to have the size of 500 GB. source_ami_filter is used to specify the base AMI used for creation of custom AMI (https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeImages.html).

4. build block defines what Packer should do with the EC2 instance after it launches. In the example template, the build block references the AMI defined by the source block above source.amazon-ebs.ubuntu. It also contains the provisioner section, which describes the instruction needed to be executed during the building of AMI. In our case, these are stored in the install_nvidia.sh and install_pyxis.bash.

Before you can build the AMI, you need to provide your AWS credentials to Packer as environment environments. These credentials have permissions to create, modify and delete EC2 instances. Refer to the documentation to find the full list IAM permissions required to run the amazon-ebs builder (https://www.packer.io/docs/builders/amazon#iam-task-or-instance-role). Add your AWS credentials as two environment variables, AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY, replacing YOUR_ACCESS_KEY and YOUR_SECRET_KEY with their respective values.

export AWS_ACCESS_KEY_ID=YOUR_ACCESS_KEY
export AWS_SECRET_ACCESS_KEY=YOUR_SECRET_KEY

Now you need to initialize Packer configuration

packer init .

This command will download all the plugins needed for image creation. Format your configuration and validate it

packer fmt .
packer validate .

Now you can finally build the AMI

packer build aws-ubuntu.pkr.hcl