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Ansible Dynamic Inventory for AWS EC2

Let Ansible discover instances by tag instead of maintaining an IP list.

1 min read

  • ansible-core 2.15
  • amazon.aws collection
  • boto3

Static inventories go stale in the cloud. The amazon.aws.aws_ec2 plugin builds inventory from the API.

ansible-galaxy collection install amazon.aws
pip install boto3 botocore

inventory/aws_ec2.yml:

plugin: amazon.aws.aws_ec2
regions: [ap-south-1]
filters:
  tag:Env: prod
  instance-state-name: running
keyed_groups:
  - key: tags.Role
    prefix: role
hostnames: [private-ip-address]
ansible-inventory -i inventory/aws_ec2.yml --graph
ansible role_web -i inventory/aws_ec2.yml -m ping
ansible-playbook -i inventory/aws_ec2.yml site.yml --limit role_web

Instances tagged Role=web land in the group role_web automatically. Use a controller with an IAM role granting ec2:DescribeInstances. For servers with no SSH exposure, the community.aws.aws_ssm connection plugin runs Ansible through Systems Manager Session Manager, which needs an S3 bucket for file transfer.