英文:
Go chi middleware to add item to response header
问题
我的概念很简单，我想要将请求ID（由chi middleware.RequestID生成）添加到响应头中。
我的代码在下面添加了X-Request-Id，但没有添加ID本身。我不确定为什么，因为在中间件链中middleware.RequestID肯定是可用的。
我的路由创建：
package restimport ("time""github.com/go-chi/chi/v5""github.com/go-chi/chi/v5/middleware""goWebAPI/pkg/database""goWebAPI/pkg/rest/mw""goWebAPI/pkg/rest/routes")func GetRouter(db *database.Database) *chi.Mux {r := chi.NewRouter()r.Use(middleware.RequestID)r.Use(mw.SendRequestID)r.Use(middleware.RealIP)r.Use(middleware.Logger)r.Use(middleware.Recoverer)r.Use(middleware.Timeout(60 * time.Second))r.Get("/", routes.IndexRoute())return r}
我的自定义中间件：
package mwimport ("context""net/http""github.com/go-chi/chi/v5/middleware")const requestIDHeader = "X-Request-Id"func SendRequestID(next http.Handler) http.Handler {fn := func(w http.ResponseWriter, r *http.Request) {ctx := r.Context()if w.Header().Get(requestIDHeader) == "" {w.Header().Add(requestIDHeader,middleware.GetReqID(context.Background()),)}next.ServeHTTP(w, r.WithContext(ctx))}return http.HandlerFunc(fn)}
我的索引路由：
package routesimport "net/http"func IndexRoute() http.HandlerFunc {fn := func(w http.ResponseWriter, r *http.Request) {w.Write([]byte("welcome"))}return fn}
英文:
My concept is simple, I would like to add the request ID (generated by chi middleware.RequestID to the response header).
My code below adds X-Request-Id but does not add the ID itself. I am not sure why, since surely it is available in the context because middleware.RequestID is higher up in the middleware chain ?
My router creation:
package restimport ("time""github.com/go-chi/chi/v5""github.com/go-chi/chi/v5/middleware""goWebAPI/pkg/database""goWebAPI/pkg/rest/mw""goWebAPI/pkg/rest/routes")func GetRouter(db *database.Database) *chi.Mux {r := chi.NewRouter()r.Use(middleware.RequestID)r.Use(mw.SendRequestID)r.Use(middleware.RealIP)r.Use(middleware.Logger)r.Use(middleware.Recoverer)r.Use(middleware.Timeout(60 * time.Second))r.Get("/", routes.IndexRoute())return r}
My custom middleware:
package mwimport ("context""net/http""github.com/go-chi/chi/v5/middleware")const requestIDHeader = "X-Request-Id"func SendRequestID(next http.Handler) http.Handler {fn := func(w http.ResponseWriter, r *http.Request) {ctx := r.Context()if w.Header().Get(requestIDHeader) == "" {w.Header().Add(requestIDHeader,middleware.GetReqID(context.Background()),)}next.ServeHTTP(w, r.WithContext(ctx))}return http.HandlerFunc(fn)}
My Index Route:
package routesimport "net/http"func IndexRoute() http.HandlerFunc {fn:= func(w http.ResponseWriter, r *http.Request) {w.Write([]byte("welcome"))}return fn}
答案1
得分: 4
我相信你的问题在这里：
middleware.GetReqID(context.Background())
这个代码尝试从一个新的空上下文中获取请求ID，但你需要当前请求的请求ID，所以应该是：
middleware.GetReqID(r.Context())
（或者，既然你已经在本地的ctx中获取了请求上下文，你也可以使用它。）
这在GetReqId的文档中有说明（我加了重点）：
> 如果存在，从给定的上下文中返回请求ID。如果找不到请求ID，则返回空字符串。
英文:
I believe your issue is here:
middleware.GetReqID(context.Background())
This tries to get the request ID of a new, empty context, but you need the request ID for the current request, meaning it should be:
middleware.GetReqID(r.Context())
(Or, since you're already grabbing the request context in local ctx, you could also use that.)
This is documented in GetReqId (emphasis mine):
> GetReqID returns a request ID from the given context if one is present. Returns the empty string if a request ID cannot be found.
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