How can I add middleware to a subrouter in Go?

问题:

I have the following code:

    apiRouter := mux.NewRoute().PathPrefix("/").Subrouter()

    // Bucket router
    bucket := apiRouter.PathPrefix("/{bucket}").Subrouter()

    bucket.Methods("HEAD").Path("/{object:.+}").HandlerFunc(
        api.HeadObjectHandler)

    // Similarly handle many more methods

I am trying to add stat collection on top of all the operations that are handled by the 'bucket' subrouter. This stat collection framework will need the 'bucket' name that gets passed down to all the handlers used by bucket.

Is there a way to add a wrapper for a subrouter in Go? I found some similar questions:

(i) Using middleware with Golang Gorilla mux subrouters But the answer in the above question can be used only with a static prefix, whereas I want to know the bucket name that matched with the "/{bucket}"

(ii) This is another link which addresses the same question using a new mux object. This might work, but it looks like heavily round about code. I'm new to golang, and I'm changing a small part of a bigger codebase, so I'm not sure about the impact to the remaining code using the first mux object.

Is there a way to do what I need without using the solution in (ii)?

回答1:

You only need to add something like this:

bucket.use(middleware)

The middleware only will be used in this subrouter.

Here is a complete example: https://gist.github.com/cep21/a3fc8e1462d19c46422c03b0466d5869