Should I use multiple Terraform projects or only one? Understanding Modules for Azure Infrastructure Setup in Git Repositories

When beginning to build resources with Terraform on Microsoft Azure using GIT repositories: Is it better to consolidate everything into a single project, or organize separate modules within different GitHub repos (projects)? Here’s an exploration of the approach towards creating modular and maintainable infrastructure.

Reconsidering Project Structures with Terraform Modules

Rather than using projects per se—which in this context could be considered terraformed code segments or “modules” as defined by HashiCorp —organize your Azure setup into discrete modules for distinct functionalities like identity and access controls, along with infrastructure provisioning:

• Identity Module - Manages user accounts, role assignments within an organization’s context in azure using Terraform configurations bundled together as a module. This encapsulates the logic needed to build these resources independently but also connect them through outputs for other modules that depend on Azure AD identity data structures (e.g., IAM permissions).

• Infrastructure Module - Designed specifically around provisioning of compute, storage and network services within azure using a module which can be reused across multiple deployments or environments with appropriate configuration adjustments for each specific requirement like regional resources setup etc..

Key Benefits: Encapsulation & Reusability

By separating your Terraform definitions into modules based on their functions, you achieve two main advantages in maintaining and scaling infrastructure projects. These benefits can be summarized as follows:

1. Encapsulation – Each module hides its complexities within a well-defined interface that takes input parameters for resources being provisioned or modified; this makes it easier to understand, develop, test separately without side effects elsewhere in the system and thus reducing risk during changes. Modules can even depend on each other’s outputs which is useful when you have multi-tier architectures (e.g., a web app module depending upon an internal networking resources).

2. Reusability – A well constructed Terraform Module, like those for ‘compute cluster’, should be able to stand alone and act as repeatable building blocks of your cloud infrastructure setup without much effort or code changes when reused within different environments (dev/staging/production setups) where configurations will differ accordingly while sharing the same high-level resource abstractions.

Design Tradeoffs & Recommendations

While a one Terraform project system might seem simpler, breaking down complex systems into smaller and focused modules helps create an organized structure that promotes maintenance ease, code reuse, scalability of your infrastructure deployments across environments:

• For Infrastructures where you need to orchestrate multiple Azure resources in a way they interact efficiently with each other (e.g., VM networking or storage integration), it’s recommended that create separate modules for these components and integrate them within higher architectural levels as required - keeping the principle of low coupling high cohesion intact.

• For Reusability, think about common patterns in your work like network policies across multiple environments; this is a good candidate to be packaged into its own module (Network Module), which could then easily deployed with minimal configuration changes for varied requirements or deployments within Azure stacks — keeping the design scalable.

• For Organizational Convenience, while it’s practical having single repository setup at times; if you decide to do so—keeping modules organized under logical folder structures (e.g., Network Resources/Computer Cluster etc.) within a larger organization wide framework may be beneficial for team collaborations and avoid potential merge conflicts when multiple teams are managing different aspects of the infrastructure simultaneously with its own repositories on GitHub or GitLab platforms respectively if preferred over centralized one repository approach..

In conclusion, while having everything under your Terraform configuration in a single project might seem tempting initially — especially for small projects—consider breaking down resources into meaningful logical groupings that can be easily managed independently within their respective modules. This helps ensure long-term sustainability and maintainable codebase by embracing the concept of encapsulation along with providing potential reuse across multiple environments if desired..