Building Scalable Go Applications: A Guide to Structuring Your Code
When it comes to building a great Go application, the structure of your code is crucial. The way you organize your files and packages sets the tone for the entire development process. In this article, we’ll explore two primary ways to structure your Go application: the flat structure and the layered architecture.
The Flat Structure: Simple and Easy to Use
The flat structure keeps all files and packages in the same directory. While it may seem like a poor way to structure projects at first, it’s perfectly suited for building libraries, simple scripts, or simple CLI applications. The main advantage of this structure is that it’s easy to work with. All created packages are located in the same directory, making it easy to modify and use them when required.
Building a Simple API Using a Flat Structure
To demonstrate a flat structure, let’s build an API for a note-taking application. We’ll use SQLite3 for storing notes and Gin for routing. Our folder structure will look like this:
notes_api_flat/
main.go
models.go
migration.go
The Benefits and Drawbacks of the Flat Structure
The flat structure is great for building simple APIs quickly without managing multiple packages. However, it’s not ideal for building complex APIs. The structure is quite limiting, and it automatically makes functions and variables available globally. There is also no true separation of concerns, making it difficult to maintain.
The Layered Architecture: A Better Approach for Complex Applications
The layered architecture groups files according to their functionalities. Packages that handle communication with the database (models) are grouped and stored differently from packages that handle requests from routes. This structure is well-suited for building APIs and other large applications.
Upgrading Our Project to a Layered Architecture
Let’s upgrade our project from a flat structure to a layered architecture. Our new folder structure will look like this:
notes_api_layered/
config/
db.go
models/
note.go
migrations/
main.go
note.go
controllers/
note.go
main.go
The Benefits of Using a Layered Structure
The largest perk to using a layered structure is that it’s easy to maintain projects that are structured this way. There is a clear separation of concerns, as each package has a single function to perform. With a layered architecture, this project is easily extensible.
Choosing the Right Structure for Your Go Application
Choosing a structure for your Go application depends on what you are building, how complex the project is, and how long you intend to work on it. For creating simple projects, using a flat structure is just fine. When the project is more complicated, though, it’s important to take a step back to rethink the application and choose a better-suited structure.