Gin フレームワークのダイナミック ルーティングとリバース プロキシの詳細な説明

r := gin.Default()
v1 := r.Group("/v1")
{
    v1.POST("/login", login)
    v1.GET("/profile", profile)
}
v2 := r.Group("/v2")
{
    v2.POST("/login", login)
    v2.GET("/profile", profile)
}

router.Handle("GET", "/hello", func(context *gin.Context) {
        context.JSON(http.StatusOK, gin.H{
            "status": "success",
            "message": "Hello World!",
        })
})

router.GET("/hello", func(context *gin.Context) {
        context.JSON(http.StatusOK, gin.H{
            "status": "success",
            "message": "Hello World!",
        })
})

router.GET("/user/:name", func(context *gin.Context) {
        name := context.Param("name")
        context.JSON(http.StatusOK, gin.H{
            "name": name,
        })
})

v1 := router.Group("/api/v1/:category")
{
    v1.GET("/books", bookList)
    v1.GET("/books/:isbn", bookDetail)
    v1.POST("/books", createBook)
    v1.PUT("/books/:isbn", updateBook)
}

func NewReverseProxy(target string) *httputil.ReverseProxy {
    url, _ := url.Parse(target)
    proxy := httputil.NewSingleHostReverseProxy(url)
    return proxy
}

router.GET("/api/*path", func(context *gin.Context) {
        NewReverseProxy("http://localhost:8080").ServeHTTP(context.Writer, context.Request)
})

var pathUrlMapping = map[string]string{
    "/api/search": "http://localhost:8080",
    "/api/report": "http://localhost:8081",
}

for path, url := range pathUrlMapping {
    r.GET(path, func(c *gin.Context) {
        proxy := NewReverseProxy(url)
        proxy.ServeHTTP(c.Writer, c.Request)
    })
}