64 lines
2.3 KiB
Go
64 lines
2.3 KiB
Go
|
// Copyright (c) Tailscale Inc & AUTHORS
|
||
|
|
// SPDX-License-Identifier: BSD-3-Clause
|
||
|
|
|
||
|
|
package tsweb
|
||
|
|
|
||
|
|
import (
|
||
|
|
"context"
|
||
|
|
"net/http"
|
||
|
|
|
||
|
|
"github.com/google/uuid"
|
||
|
|
)
|
||
|
|
|
||
|
|
// RequestID is an opaque identifier for a HTTP request, used to correlate
|
||
|
|
// user-visible errors with backend server logs. The RequestID is typically
|
||
|
|
// threaded through an HTTP Middleware (WithRequestID) and then can be extracted
|
||
|
|
// by HTTP Handlers to include in their logs.
|
||
|
|
//
|
||
|
|
// RequestID is an opaque identifier for a HTTP request, used to correlate
|
||
|
|
// user-visible errors with backend server logs. If present in the context, the
|
||
|
|
// RequestID will be printed alongside the message text and logged in the
|
||
|
|
// AccessLogRecord.
|
||
|
|
//
|
||
|
|
// A RequestID has the format "REQ-1{ID}", and the ID should be treated as an
|
||
|
|
// opaque string. The current implementation uses a UUID.
|
||
|
|
type RequestID string
|
||
|
|
|
||
|
|
// RequestIDHeader is a custom HTTP header that the WithRequestID middleware
|
||
|
|
// uses to determine whether to re-use a given request ID from the client
|
||
|
|
// or generate a new one.
|
||
|
|
const RequestIDHeader = "X-Tailscale-Request-Id"
|
||
|
|
|
||
|
|
// SetRequestID is an HTTP middleware that injects a RequestID in the
|
||
|
|
// *http.Request Context. The value of that request id is either retrieved from
|
||
|
|
// the RequestIDHeader or a randomly generated one if not exists. Inner
|
||
|
|
// handlers can retrieve this ID from the RequestIDFromContext function.
|
||
|
|
func SetRequestID(h http.Handler) http.Handler {
|
||
|
|
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
|
||
|
|
id := r.Header.Get(RequestIDHeader)
|
||
|
|
if id == "" {
|
||
|
|
// REQ-1 indicates the version of the RequestID pattern. It is
|
||
|
|
// currently arbitrary but allows for forward compatible
|
||
|
|
// transitions if needed.
|
||
|
|
id = "REQ-1" + uuid.NewString()
|
||
|
|
}
|
||
|
|
ctx := withRequestID(r.Context(), RequestID(id))
|
||
|
|
r = r.WithContext(ctx)
|
||
|
|
h.ServeHTTP(w, r)
|
||
|
|
})
|
||
|
|
}
|
||
|
|
|
||
|
|
type requestIDKey struct{}
|
||
|
|
|
||
|
|
// RequestIDFromContext retrieves the RequestID from context that can be set by
|
||
|
|
// the SetRequestID function.
|
||
|
|
func RequestIDFromContext(ctx context.Context) RequestID {
|
||
|
|
val, _ := ctx.Value(requestIDKey{}).(RequestID)
|
||
|
|
return val
|
||
|
|
}
|
||
|
|
|
||
|
|
// withRequestID sets the given request id value in the given context.
|
||
|
|
func withRequestID(ctx context.Context, rid RequestID) context.Context {
|
||
|
|
return context.WithValue(ctx, requestIDKey{}, rid)
|
||
|
|
}
|