Tuesday, October 6, 2020

Provisioning AWS infrastructure using Ansible

Cloud infrastructure provision can be automated using code. The main advantage is that the process can be repeated with consistent output and the code can be version controlled in github, bitbucket or something else.

AWS comes with CloudFormation for automation of the provisioning of the AWS infrastructure, the main disadvantage is that CloudFormation template (code) is very specific to AWS and takes a lot of effort to migrate to some other Cloud. In this blog we will look at Ansible using which infrastructure can be provisioned for multiple Clouds and also migrating code to provision code to some Cloud doesn't take as much effort as with CloudFormation.

We would installing Ansible on an Ubuntu EC2 instance for provisioning of the AWS infrastructure. Ansible can be setup on Windows also, but as we install more and more softwares on Windows (host OS) directly, it becomes slow over time. So, I prefer to launch an EC2, try a few things and tear it down once done with it. Anyway, lets look at setting up Ansible and create AWS infrastructure on it.

 Step 1: Create an Ubuntu instances (t2.micro) and connect to it.

Step 2: Install Python and boto (AWS SDK for Python) on the EC2 instance using the below commands.

   sudo apt-get update
   sudo apt-get install python2.7 python-pip -y
   pip install boto

Step 3: Install Ansible using the below command.

   sudo apt install software-properties-common -y
   sudo apt-add-repository --yes --update ppa:ansible/ansible
   sudo apt install ansible -y

Step 4: Go to the IAM Management Console here (1) and create the Access Keys. Note them down.

Step 5: Export the Access Keys using the below commands. Make sure to replace 'ABC' and 'DEF' with the Access Keys which have been generated in the previous step.


Step 6: Create a file called "launch-ec2.yaml" with the below content. Make sure to replace the highlighted sections.

- name: Provision a set of instances
  hosts: localhost
    - name: Provision a set of instances
        key_name: my-keypair
        region: us-east-1
          - sg-0fa7df1dab4d7ebcb
          - sg-040f6c6ef9932dbb5
        instance_type: t2.micro
        image: ami-0bcc094591f354be2
        wait: yes
          Name: Demo
        exact_count: 1
        count_tag: Name
        assign_public_ip: yes
        vpc_subnet_id: subnet-59120577

Step 7: Execute the below command to launch an EC2 instance.

ansible-playbook launch-ec2.yaml

Step 8: Go to the EC2 Management Console and notice a new EC2 instance has been launched with the Name:Demo tag. Make sure to note down the "Instance ID" of the newly created EC2 instance.

Step 9: Create a file called "terminate-ec2.yaml" with the below content. Make sure to replace the highlighted section with the Instance ID of the EC2 got from the previous step.

- name: Terminate instances
  hosts: localhost
    - name: Terminate instances
        state: "absent"
        instance_ids: "i-08ef0942aabbc45d7"
        region: us-east-1
        wait: true

Step 10: Execute the below command to launch an EC2 instance.

ansible-playbook terminate-ec2.yaml

Step 11: Go back to the EC2 Management Console and notice that the EC2 which was created by Ansible will be in a terminated status within a few minutes.


By using YAML code, we were able to launch and terminate instance. Ansible allows to do lot of complicated things than this, this is something to start with. As mentioned earlier Ansible allows easy migration to some other Cloud vendor when compared to AWS CloudFormation. BTW, Ansible has been bought by Red Hat which has been bought by IBM. So, Ansible is part of IBM now.

For reference, here is the yaml code for launching and terminating the EC2 instances, the screen has been split horizontally using tmux.

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