Go - how to organize code for dynamic packages

Question

I have a small web application written in Go. It is created a base for a larger system and I would like it to be extendable where components can be added/removed without needing this base to be modified in any way.

The structure is currently:

 App Modules Core ... Core Files Here ... app.go main.go

app.go will contain a routing method which should take a web request and based on the request path know which module is responsible for handling the request. Each module/component having its on controller.

Each component will have its own package name so i think this is going to be impossible since go forces an explicit import.

For example i may add a new module/component called say blog such as:

 App Modules Core ... Core Files Here ... controller.go Blog ... Blog Files Here ... controller.go app.go main.go

thwd · Accepted Answer · 2013-08-10 11:57:24Z

There are several ways to achieve your goal. Since Go does not support dynamically loaded libraries at the moment, you need to probably recompile your application whenever you add/remove any components. The simplest way therefore would be a yourapp/core package with the following:

an Application type with an ServeHTTP method that acts as your main application
a Component interface that all your components have to implement. Your might want include a BaseUrl() string and a ServeHTTP method there.
a Register method to your Application type, that can be used to add new components to your app.

Your components can then be implemented in separate packages (e.g. yourapp/blog) and they will probably depend on your yourapp/core package.

The only thing that still needs to be "user-editable" is the main.go file, which might look like this:

func main() { app := core.NewApplication() app.Register(blog.Blog{ Title: "My Personal Blog", }) app.Register(...) app.Run() }

Another approach might be to define an RPC interface for your components (which might include functions like RegisterComponent, UnregisterComponent and a GetGlobalConfig).

Then, you can run those components in separate processes which has the advantage that you can start/stop/reload those components dynamically and they can not break your main app. Take a look at the net/rpc package and maybe even httputil.NewSingleHostReverseProxy if you want to use this approach instead.

Upvoted. A variant might be that each component does core.Register(...) in an init() function.

Collectives™ on Stack Overflow

Go - how to organize code for dynamic packages

1 Answer 1

1 Comment

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Related