Web Server in Azure with Ansible

The goal is to provision one or more web server instances behind a load balancer on Azure automatically. These instances, while they are typically identical to one another, can run a mix of different Linux distributions (just for fun).

Requirements

Azure credentials

To authenticate via service principal to Azure, you need to provide these variables; subscription_id, client_id, secret and tenant or set them as environment variables;AZURE_SUBSCRIPTION_ID, AZURE_CLIENT_ID, AZURE_SECRET and AZURE_TENANT. More details on the following links:

• AZURE_SUBSCRIPTION_ID: Find your Azure subscription
• AZURE_CLIENT_ID and AZURE_TENANT: Register an application with Azure AD and create a service principal
• AZURE_SECRET: Create a new application secret

SSH Public key

You need to provide an SSH Key pair, so Azure can add the public SSH Key to ~/.ssh/authorized_keys in the instances it creates. Ansible uses the Private Key to configure these instances after they are created.

Creating a Job Template to Deploy the Web Server(s)

Follow these steps to provision the Web Server(s).

1. Create a Project with for this repo (https://github.com/nleiva/ansible-webserver-azure). I called the Project Azure WebServer in the example below.

2. Create a Microsoft Azure Resource Manager credential with your Azure service principal parameters.

3. The number and operating system of the backend servers is defined via the variable vms. Its default value is defined in the vms file. It list 2 instances; one running centos, and the other one ubuntu (these are the two distributions supported at the moment). You can override this with a new vms definition as an Extra Variable.

vms:
  1: centos
  2: ubuntu

4. Put all these pieces together in a Job Template pointing to create_resources.yml.

5. Run the Job Template.

It should look like this when it finishes:

Accessing the Web Server

We distribute the traffic among the instances using an Azure Load Balancer to prevent failure in case any of the virtual machines fail. By default the web server is at http://testbed.eastus.cloudapp.azure.com/. You can modify this with the variable prefix. Its default value is testbed.

This URL will take you to one of the backend VM's. For example:

VM 1

VM 2

Deleting the resources

You can create a similar Job Template pointing to delete_resources.yml instead.

And run it.

Run from an Execution Environment

You can alternatively run this with ansible-navigator.

ansible-navigator run create_resources.yml

EE Create Web Server

EE Delete Web Server

Note: I use podman as my container engine (container-engine). You can change to another alternative in the ansible navigator config file.

Q: How do I use my SSH keys with an execution environment?

From FAQ

A: The simplest way to use SSH keys with an execution environment is to use ssh-agent and use default key names....

... ansible-navigator will automatically volume mount the user’s SSH keys into the execution environment in 2 different locations to assist users not running ssh-agent.

...the keys are mounted into the home directory of the default user within the execution environment as specified by the user’s entry in the execution environment’s /etc/passwd file. When using OpenSSH without ssh-agent, only keys using the default names (id_rsa, id_dsa, id_ecdsa, id_ed25519, and id_xmss) will be used. ...

-v /home/current_user/.ssh/:/root/.ssh/

Note: When using ansible_ssh_private_key_file with execution environments, the path to the key needs to reference it’s location after being volume mounted to the execution environment. (eg /home/runner/.ssh/key_name or /root/.ssh/key_name). It may be convenient to specify the path to the key as ~/.ssh/key_name which will resolve to the user’s home directory with or without the use of an execution environment.

Run from the Ansible Core CLI

Check ansible_core.