ami2

Overview

This documents provides some help on how to use pre-configured Amazon Machine Image descriptions to create a nomad cluster.

Amazon Linux 2

https://aws.amazon.com/de/amazon-linux-2/release-notes/

Certain flavors with different supported functionalities are supported.

AMI without ECR support

The packer definition nomad-consul-docker.json creates an ami that can load docker images from public repositories such as docker hub.

• Nomad
• Consul
• Docker
• privileged mode activated

AMI with ECR support

The packer definition nomad-consul-docker-ecr.json creates an ami with ECR support. That means you can load docker images hosted at a AWS ECR of your account.

• Nomad
• Consul
• Docker
• privileged mode activated
• AWS ECR plugin

Create the Amazon Machine Image

Prepare

AWS Credentials

As described at Authentication Packer you can use static, environment variables or shared credentials.

# environment variables
export AWS_ACCESS_KEY_ID=<your access key id>
export AWS_SECRET_ACCESS_KEY=<your secret key>
export AWS_DEFAULT_REGION=us-east-1

Goss Provisioner

The packer builds are verified during the build process using goss. Goss needs to be available as provisioner for packer to build AMIs.

# Install goss provisioner
make prepare

Build

The following can be applied for nomad-consul-docker-ecr.json and nomad-consul-docker.json.

# Build the AMI using the AWS_DEFAULT_REGION
make ami

# If the AMI should be available in multiple regions
make ami additional_aws_regions="us-east-1,us-east-2"

Packer Details

Under the hood AMI are created using packer, please find below more sophisticated examples.

# Build it using the default variables specified in the packer file.
# Important variables are:
# aws_region - The region where the ami is build in. The exported account settings have to match to this region.
# ami_regions - A list (comma separated) of regions this ami should be available in as well (will be copied over).
# aws_account_ids - A list of AWS account Id's (comma separated list) this ami should be allowed to used from.
packer build nomad-consul-docker-ecr.json

# Build the AMI in us-east-1 and make it available in us-east-2 as well.
packer build -var 'aws_region=us-east-1' -var 'ami_regions=us-east-1,us-east-2' nomad-consul-docker-ecr.json

# Build the AMI in us-east-1, make it available in us-east-2 as well and grant access from account 123456789 and 987654321.
packer build -var 'aws_region=us-east-1' -var 'ami_regions=us-east-1,us-east-2' -var aws_account_ids='123456789,987654321' nomad-consul-docker-ecr.json