The EC2 AMI generation feature

The AWS EC2 AMI feature was taken from meta-aws-ewaol. And turned into a more generic solution that will allow you by simple adding those lines to your local.conf to build an AWS EC2 AMI image that can be uploaded with a simple included script to your AWS account.

INHERIT += "aws-ec2-image"
MACHINE = "aws-ec2-arm64"
# or MACHINE = "aws-ec2-x86-64"

Build instructions

Pre-requisites

1. An AWS account and the necessary IAM rights to create EC2 instances, EBS snapshots, EBS volumes, S3 buckets, and IAM roles and policies.
2. A VPC with appropriate subnets and routing required to access the build server.
3. The resources created by deploying the VMImport CloudFormation Template (roles, policies, S3 bucket for images).
   1. Take note of the outputs of the stack deployment as they'll be needed in the following steps

Build Dependencies

To be able to execute the create-ec2-ami.sh script AWS CLI v2 is necessary.

1. Install AWS CLI v2

   curl "https://awscli.amazonaws.com/awscli-exe-linux-aarch64.zip" -o "/tmp/awscliv2.zip"
   unzip /tmp/awscliv2.zip -d /tmp
   sudo /tmp/aws/install

Building

1. Build your image as usual. For example:

   bitbake core-image-minimal

Creating AMI from image file

From meta-aws scripts/ec2-ami directory, run the bash script. Replace <S3_BUCKET_IMPORT_IMAGES> with the bucket name created by the CloudFormation Stack in the pre-requisites section and choose the appropriate size for the future root disk of AMI to have by entering a number (e.g. 16) in place of <AMI_DISK_SIZE_IN_GB>, use the created <IMAGE_NAME> and <MACHINE_NAME> :

meta-aws/scripts/ec2-ami/create-ec2-ami.sh <S3_BUCKET_IMPORT_IMAGES> <AMI_DISK_SIZE_IN_GB> <IMAGE_NAME> <MACHINE_NAME>

e.g.

meta-aws/scripts/ec2-ami/create-ec2-ami.sh amitest-bucket 16 core-image-minimal aws-ec2-arm64

Launch the EC2 Image as usual using your newly created AMI

1. In the Web Console, Navigate to EC2->Images->AMIs
2. Select the desired AMI and click 'Launch instance from Image'
3. Follow the wizard as usual
4. Access the image with the previously provided ssh key with user user

Limitations

The image does not yet support online expansion of partitions/filesystems via cloud-init. Follow the below workaround to expand root partition and filesystem (this can be used as user data script):

#!/bin/sh

# disabling swap
swapoff -a
sed -i '/.*swap.*/d' /etc/fstab
# trick to fix GPT
printf "fix\n" | parted ---pretend-input-tty /dev/nvme0n1 print
# remove partition 3 (swap)
parted -s /dev/nvme0n1 rm 3
# resize partition 2 to use 100% of available free space
parted -s /dev/nvme0n1 resizepart 2 100%
# resizing ext4 filesystem
resize2fs /dev/nvme0n1p2

Future Enchancements

• Enable support for expanding filesystem on boot with cloud-init which depends on growpart. This needs cloud-utils which is not in openembedded recipes yet.