http sample with go.uber.org/dig

package main

import (
    "fmt"
    "net/http"

    "go.uber.org/dig"
)

type Handler struct {
    Greeting string
    Path     string
}

func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "%s from %s", h.Greeting, h.Path)
}

func NewHello1Handler() HandlerResult {
    return HandlerResult{
        Handler: Handler{
            Path:     "/hello1",
            Greeting: "welcome",
        },
    }
}

func NewHello2Handler() HandlerResult {
    return HandlerResult{
        Handler: Handler{
            Path:     "/hello2",
            Greeting: "😄",
        },
    }
}

type HandlerResult struct {
    dig.Out

    Handler Handler `group:"server"`
}

type HandlerParams struct {
    dig.In

    Handlers []Handler `group:"server"`
}

func RunServer(params HandlerParams) error {
    mux := http.NewServeMux()
    for _, h := range params.Handlers {
        mux.Handle(h.Path, h)
    }

    server := &http.Server{
        Addr:    ":8080",
        Handler: mux,
    }
    if err := server.ListenAndServe(); err != nil {
        return err
    }

    return nil
}

func main() {
    container := dig.New()

    container.Provide(NewHello1Handler)
    container.Provide(NewHello2Handler)

    container.Invoke(RunServer)
}