Using Ansible 2 to automate the creation of a Flask + Gunicorn + NGINX Web Application on Ubuntu Vagrant Machine

NOTE: This is a simple template, but it demonstrates how automation saves a ton of time instead of writing a ton of bash scripts to setup a webserver. This was done in a test environment on a vagrant instance of Ubuntu Bionic.

Pre-requisites

Install VirtualBox and Vagrant

• CraftedTech Blog Instructions: https://craftedtech.net/post/vagrant-virtualbox-setup/

Install VirtualBox

• Installation: https://www.virtualbox.org/wiki/Downloads

Setup Vagrant

• Installation: https://www.vagrantup.com/docs/installation/
• Useful Vagrant Specific Commands: https://www.vagrantup.com/docs/cli/

Spin up Ubuntu to setup Ansible Server

• vagrant box list - Shows your currently installed boxes

Create a vagrant project folder

If using Powershell on Windows, make sure you open it as administrator

• sudo mkdir ansible-server
• vagrant box add ubuntu/bionic64 - Installs Ubuntu Bionic 64-bit (Ubuntu 18.04)
  • This may take a while as it needs to download the instance
• Open the Vagrantfile that's pulled down, if you have issues, just run the following command: vagrant init ubuntu/bionic64, it should look like this:

Vagrant.configure("2") do |config|
  # Every Vagrant development environment requires a box. You can search for
  # boxes at https://vagrantcloud.com/search.
  config.vm.box = "ubuntu/bionic64"
  config.vm.hostname = "ansible-box"

  # Create a public network, which generally matched to bridged network.
  # Bridged networks make the machine appear as another physical device on
  # your network.
  config.vm.network "public_network"
end

• NOTE: The above configuration file is the vagrant config for your machine, you'll notice that the network is set to public network, as it explains, your hosting machine will act as a bridge to bring your machine onto the network. You could set the network to be private if you like, if you do, look at Vagrant's documentation to understand private networks.
• vagrant up - Brings up the machine
• vagrant ssh - SSH into your machine
• vagrant halt - shuts the vagrant machine down, you could use -f argument to force it
• vagrant destroy - stops the machine and for all intents and purposes, destroys it, you cannot recover this instance if you run this command

Setting up Ansible 2

Get Latest Releases via Apt

• sudo apt-get update
• sudo apt-get install software-properties-common

Install Ansible

• Via Apt
  • sudo apt-add-repository --yes --update ppa:ansible/ansible - This can take a while
  • sudo apt-get install ansible -y
• Via pip
  • sudo apt install python3-pip
  • sudo pip3 install ansible

Configure Ansible

• sudo vim /etc/ansible/ansible.cfg - make sure to uncomment the host_key_checking and set it to False per the following:

[defaults]
host_key_checking = False

• Configure what hosts Ansible Server will connect to
  • Each one of the target machines need to have python and SSH setup
  • sudo vim /etc/ansible/host - the following code block is an example of a setup

[webservers]
192.168.1.10 ansible_ssh_port=22 ansible_ssh_user=vagrant ansible_ssh_private_key_file=/home/vagrant/.ssh/id_rsa

• NOTE: Verify the SSH port, with Vagrant sometimes this can change, a good command to verify this is to run this command on the machine in question: sudo netstat -tulpn, this will show what ports are open and listening

Prep the Webserver using Ansible

• Use the above instructions to setup your vagrant machine
• On a vagrant machine, SSH is already preconfigured
• Git clone the repo and let's do some work
• cd /etc/ansible; sudo mkdir playbooks; cd playbooks
• git clone https://github.com/TAMUSA-ACM/ansible-flask-gunicorn-nginx.git && cd ansible-flask-gunicorn-nginx
• Run this script from your ansible server to setup your target webserver
  • Use the following command to execute ansible execution of the YML script: sudo ansible-playbook prepare_ansible_target.yml -i /etc/ansible/hosts -u vagrant -k --ask-sudo-pass - This will prompt you for the password for vagrant, enter the password and this will automatically install python for you, which is needed to do automation. This will also enter your private SSH key into authorized_keys on the target machine, saving you from having to enter creds in the future

Execute Webserver Playbook for Deployment

• Using my playbook, a lot of the heavy lifting thankfully has been done, if you are curious to see the details of it, feel free to look through the YML Script
• Execute the script from the Ansible Server: sudo ansible-playbook webserver-setup.yml -u root -i /etc/ansible/hosts

Now just explore to the site and it should have your hello world!

References

• Support David Cohen, author of Ansible 2 for Beginners: https://www.udemy.com/ansible-2-for-beginners/