DevOps Task Documentation

This repository contains the implementation for a DevOps task involving containerization, infrastructure provisioning, and configuration management for a Python metrics exporter. The solution uses Docker, Terraform, and Ansible and is designed to run on Yandex.Cloud.

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Task Overview

Objective:

1. Containerize a Python script (exporter.py) that exports Prometheus metrics.
2. Provision two virtual machines using Terraform:
   • Application Host (Ubuntu 22.04)
   • Monitoring Host (Ubuntu 22.04)
3. Configure the hosts using Ansible:
   • Application Host:
     • Configure a firewall.
     • Install Docker.
     • Deploy the metrics exporter container.
   • Monitoring Host:
     • Configure a firewall.
     • Install Prometheus.
     • Set up Prometheus to scrape metrics from the Application Host.

Environment:

• Preferred: Yandex.Cloud.
• Alternative: Any other Russian cloud provider.

Deliverables:

• A mono-repository containing all necessary code.
• Deployed machines accessible via SSH.
• Demonstration of Prometheus collecting metrics.

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Repository Structure

/
|-- docker/
|   |-- Dockerfile         # Dockerfile to containerize the Python script
|   |-- exporter.py        # Python script exporting Prometheus metrics
|
|-- terraform/
|   |-- main.tf            # Terraform configuration for provisioning VMs
|
|-- ansible/
|   |-- app_host.yml       # Ansible playbook for the Application Host
|   |-- monitoring_host.yml # Ansible playbook for the Monitoring Host
|
|-- README.md              # Documentation (this file)

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Instructions

Prerequisites

1. Terraform installed on your local machine.
2. Ansible installed on your local machine.
3. Docker installed locally to build the Docker image.
4. A Yandex.Cloud account with the necessary credentials:
   • Cloud ID
   • Folder ID
   • Yandex.Cloud API token
5. SSH key pair for accessing the provisioned VMs.

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Step 1: Build and Push the Docker Image

1. Navigate to the docker/ directory:

   cd docker

2. Build the Docker image:

   docker build -t exporter:latest .

3. Optionally, push the Docker image to a container registry if required.

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Step 2: Provision Infrastructure with Terraform

1. Navigate to the terraform/ directory:

   cd terraform

2. Initialize Terraform:

   terraform init

3. Apply the Terraform configuration:

   terraform apply

   • You will be prompted to input variables (e.g., Cloud ID, Folder ID, etc.).
   • Terraform will provision two VMs: Application Host and Monitoring Host.

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Step 3: Configure Hosts with Ansible

1. Update the inventory file to include the IPs of the provisioned VMs. Example:

   [application_host]
   <APPLICATION_HOST_IP>
   
   [monitoring_host]
   <MONITORING_HOST_IP>

2. Run the playbook for the Application Host:

   ansible-playbook -i inventory ansible/app_host.yml

3. Run the playbook for the Monitoring Host:

   ansible-playbook -i inventory ansible/monitoring_host.yml

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Step 4: Validate Prometheus Metrics Collection

1. SSH into the Monitoring Host:

   ssh ubuntu@<MONITORING_HOST_IP>

2. Access the Prometheus web UI:
   • URL: http://<MONITORING_HOST_IP>:9090
3. Verify that Prometheus is scraping metrics from the Application Host:
   • Navigate to Status > Targets.
   • Ensure the exporter target is listed and in the "UP" state.

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Deliverables

1. Mono-repository with the following structure:
   • docker/ (Dockerfile and Python script).
   • terraform/ (Terraform configuration).
   • ansible/ (Ansible playbooks).
2. Deployed virtual machines accessible via SSH.
3. Demonstration of metrics collection by Prometheus.

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Additional Notes

• This repository includes placeholders (e.g., <APPLICATION_HOST_IP>, <YOUR_SSH_PUBLIC_KEY>). Replace these with actual values before running the scripts.
• For CI/CD, GitHub Actions can be integrated to automate Docker image builds and Terraform deployments.