it's possible to use cloud init to install ansible and then download and install ansible playbooks from s3.
e.g.
runcmd:
- yum clean all
- yum install --enablerepo=epel -y gcc python27 python27-devel python27-pip python27-boto libselinux-python aws-cli
- /usr/bin/pip-2.7 install --upgrade pip-2.7
- alternatives --set python /usr/bin/python2.7
- /usr/bin/pip-2.7 install --upgrade ansible
- mkdir /etc/ansible
- aws s3 cp s3://my_bucket/ansible /etc/ansible/ --recursive
- echo localhost > /etc/ansible/hosts
- /usr/local/bin/ansible-playbook /etc/ansible/playbook.yml -i /etc/ansible/hosts