UserDataに以下のコードを挿入し実行してください。 CFn内のUserDataでも可です。
#!/bin/sh
yum update -y
yum install epel-release -y
yum install gcc python-devel python-crypto python-pip git openssl-devel libffi-devel -y
export PATH=$PATH:/usr/local/bin
easy_install pip
pip install --upgrade pip
pip install --upgrade setuptools
pip install ansible
cd ~
git clone https://github.com/cloudpack/ansible.git
cat <<EOF > ansible/group_vars/all.yml
datadog: true
DD_API_KEY: xxxxxxxxxxxxxxxx
EOF
ansible-playbook ansible/xxx.yml
# sshdを有効にしたい場合
# ansible-playbook ansible/xxx.yml -e "sshd=enable"
"cat <<EOF > ansible/group_vars/all.yml\n",
"datadog: ",
{ "Ref": "datadog" },
"\n",
"DD_API_KEY: ",
{ "Ref": "DD_API_KEY" },
"\n",
"EOF\n",