英文:
How to restrict web server written in golang to allow a particular address instead of a pattern?
问题
当我使用以下代码时：
http.HandleFunc("/", serveRest) // serveRest 是处理请求的方法
http.ListenAndServe("localhost:4000", nil)
它将接受以"/"开头的所有请求。我如何限制它只服务于"localhost:4000"而不是每个地址，比如"localhost:4000/*"？
还有，你们能给我推荐一个好的Go教程吗？
英文:
When I use
http.HandleFunc("/", serveRest) //serveRest is the method to handle request
http.ListenAndServe("localhost:4000", nil)
It will accept all request starting with "/". How do I restrict it to serve only "localhost:4000" instead of every address like "localhost:4000/*"?
And can you guys suggest me a good tutorial for Go?
答案1
得分: 7
你注册处理程序的URL模式在http.ServeMux类型中有详细说明：
模式可以是固定的、根路径，例如"/favicon.ico"，或者是根子树，例如"/images/"（注意末尾的斜杠）。较长的模式优先于较短的模式，因此如果同时为"/images/"和"/images/thumbnails/"注册了处理程序，后者将用于以"/images/thumbnails/"开头的路径，而前者将用于"/images/"子树中的任何其他路径的请求。
请注意，由于以斜杠结尾的模式表示根子树，模式"/"匹配所有未被其他注册模式匹配的路径，而不仅仅是路径为"/"的URL。
因此，不幸的是，没有仅匹配根路径（"/"）的模式。
但是，你可以在处理程序中轻松检查这一点，并在请求路径不是根路径时执行你想要的操作：
func serveRest(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
w.Write([]byte("不是根路径！"))
return
}
w.Write([]byte("你好，这是根路径！"))
}
如果你想为非根路径返回HTTP 404 Not found错误：
func serveRest(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.NotFound(w, r)
return
}
w.Write([]byte("你好！"))
}
Go教程：https://tour.golang.org/
还可以在SO上查看<kbd>Go</kbd>标签信息，其中有一个Go教程部分。
英文:
The URL pattern to which you register your handlers is documented in the http.ServeMux type:
> Patterns name fixed, rooted paths, like "/favicon.ico", or rooted subtrees, like "/images/" (note the trailing slash). Longer patterns take precedence over shorter ones, so that if there are handlers registered for both "/images/" and "/images/thumbnails/", the latter handler will be called for paths beginning "/images/thumbnails/" and the former will receive requests for any other paths in the "/images/" subtree.
>
> Note that since a pattern ending in a slash names a rooted subtree, the pattern "/" matches all paths not matched by other registered patterns, not just the URL with Path == "/".
So unfortunately there is no pattern which matches only the root ("/").
But you can easily check this in your handler, and do whatever you want to if the request path is not the root:
func serveRest(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
w.Write([]byte("Not root!"))
return
}
w.Write([]byte("Hi, this is the root!"))
}
If you want to return HTTP 404 Not found error for non-roots:
func serveRest(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.NotFound(w, r)
return
}
w.Write([]byte("Hi!"))
}
And Go tutorial: https://tour.golang.org/
Also check out the <kbd>Go</kbd> tag info here on SO, it has a section Go Tutorials.
答案2
得分: 1
你可以查看https://github.com/julienschmidt/httprouter
根据它的自述文件：
> 仅显式匹配：与其他路由器（如http.ServeMux）不同，请求的URL路径可能与多个模式匹配。因此，它们具有一些尴尬的模式优先级规则，如最长匹配或先注册先匹配。通过设计，该路由器的请求只能完全匹配一个或零个路由。因此，也不会出现意外匹配，这对于SEO和改善用户体验非常有用。
这里有一些很好的Go入门视频内容。
英文:
You could check out
https://github.com/julienschmidt/httprouter
Per its readme:
> Only explicit matches: With other routers, like http.ServeMux, a
> requested URL path could match multiple patterns. Therefore they have
> some awkward pattern priority rules, like longest match or first
> registered, first matched. By design of this router, a request can
> only match exactly one or no route. As a result, there are also no
> unintended matches, which makes it great for SEO and improves the user
> experience.
Here is some good video content to get started in Go.
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