1.) Pass this info in userdata while setting up instance or do this post installation.
yum update -y
yum install awscli wget ruby -y
cd /home/ec2-user/
wget https://aws-codedeploy-$(curl -s 169.254.169.254/latest/meta-data/placement/availability-zone | sed 's/.$//').s3.amazonaws.com/latest/install
chmod +x ./install
./install auto"
service codedeploy-agent restart