If your OS provisioning system supports cloud-init, cloud-config, or similar initialization and provisioning mechanisms, you can easily install Docker and the Nirmata Agent as follows (assumes use of Direct Connect / Other Host Groups):

Ubuntu:

#!/bin/bash -x
# Install Docker
wget -qO- https://get.docker.com/ | sh

# Install Nirmata Agent
sudo curl -sSL https://www.nirmata.io/nirmata-host-agent/setup-nirmata-agent.sh | sudo sh -s -- --cloud other --hostgroup <key>

CentOS:

#!/bin/bash -x
# Install Docker
sudo yum update -y

sudo tee /etc/yum.repos.d/docker.repo <<-'EOF'
[dockerrepo]
name=Docker Repository
baseurl=https://yum.dockerproject.org/repo/main/centos/7/
enabled=1
gpgcheck=1
gpgkey=https://yum.dockerproject.org/gpg
EOF

sudo yum install -y docker-engine
sudo systemctl enable docker.service
sudo systemctl start docker

# Install Nirmata Agent
sudo curl -sSL https://www.nirmata.io/nirmata-host-agent/setup-nirmata-agent.sh | sudo sh -s -- --cloud other --hostgroup <key>

Amazon Linux:

#!/bin/bash -x
# Install docker
sudo yum update -y
sudo yum install -y docker
sudo service docker start  

# Install Nirmata Agent
sudo curl -sSL https://www.nirmata.io/nirmata-host-agent/setup-nirmata-agent.sh | sudo sh -s -- --cloud other --hostgroup <key>