Cloud Infrastructure
Overview
This section explains how we organized our infrastructure.
Everything regarding the deployment of apps and services is divided into two repositories:
- polinetworkorg/terraform - Contains the Terraform code to deploy the infrastructure. This defines the resources that are created on Azure, from specific things like KeyVaults, Disks, and VMs, to the Kubernetes cluster itself.
- polinetworkorg/polinetwork-cd - Our GitOps repo, contains the manifests that define deployments specific for each app or service. This repository is connected to the ArgoCD instance running on the Kubernetes cluster.
Terraform: Definition and Purpose
The Terraform repository is responsible for managing and provisioning cloud infrastructure. In simple terms, it defines and creates the resources needed for the infrastructure, such as:
- Networks and subnets (Virtual Networks, Subnets, Security Groups)
- Virtual machines (VMs, Containers, Kubernetes Clusters)
- Databases (MariaDB, PostgreSQL)
- Storage (Blob Storage, Virtual Disks, File Shares)
- Security services (Identity and Access Management, Firewalls)
The code in Terraform describes these resources declaratively: it defines the desired state, and Terraform applies the necessary changes to reach that state. This repository is primarily used to create and modify the cloud infrastructure where applications will run.
PoliNetwork-CD: Definition and Purpose
The PoliNetwork-CD (Continuous Deployment) repository, on the other hand, is dedicated to managing and updating applications once the infrastructure has been created. Specifically, it uses GitOps tools (in our case, ArgoCD, but Flux is also an opinionated option) to:
- Define application deployments in Kubernetes (or Kustomize, Helm, etc.)
- Automatically update applications when code changes
- Manage application configurations (e.g., configuration files, environment variables)
- Monitor the state of applications and ensure they remain in sync with the repository
While Terraform is responsible for infrastructure, PoliNetwork-CD focuses on managing the lifecycle of applications running on that infrastructure, ensuring that code changes are applied automatically and securely.
Key Difference: Infrastructure vs. Deployment
| Repository | Main Purpose | Example of Managed Resources |
|---|---|---|
| Terraform | Creates and manages cloud infrastructure | Networks, VMs, databases, storage, security |
| PoliNetwork-CD | Automates application deployment and updates | Deployments, configurations, GitOps updates |
In summary, Terraform builds the foundation on which applications run, while PoliNetwork-CD manages the deployment and continuous updating of applications. Both repositories work together to ensure a scalable and efficient cloud infrastructure.
📄️ Terraform
Detailed overview of our Azure-based infrastructure managed via the polinetworkorg/terraform repository.