Update

vendor/tailscale.com/tsweb/request_id.go

@@ -0,0 +1,77 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package tsweb
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"tailscale.com/util/ctxkey"
+	"tailscale.com/util/rands"
+)
+
+// 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
+
+// String returns the string format of the request ID, for use in e.g. setting
+// a [http.Header].
+func (r RequestID) String() string {
+	return string(r)
+}
+
+// RequestIDKey stores and loads [RequestID] values within a [context.Context].
+var RequestIDKey ctxkey.Key[RequestID]
+
+// 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"
+
+// GenerateRequestID generates a new request ID with the current format.
+func GenerateRequestID() RequestID {
+	// Return a string of the form "REQ-<VersionByte><...>"
+	// Previously we returned "REQ-1<UUIDString>".
+	// Now we return "REQ-2" version, where the "2" doubles as the year 2YYY
+	// in a leading date.
+	now := time.Now().UTC()
+	return RequestID("REQ-" + now.Format("20060102150405") + rands.HexString(16))
+}
+
+// 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) {
+		var rid RequestID
+		if id := r.Header.Get(RequestIDHeader); id != "" {
+			rid = RequestID(id)
+		} else {
+			rid = GenerateRequestID()
+		}
+		ctx := RequestIDKey.WithValue(r.Context(), rid)
+		r = r.WithContext(ctx)
+		h.ServeHTTP(w, r)
+	})
+}
+
+// RequestIDFromContext retrieves the RequestID from context that can be set by
+// the SetRequestID function.
+//
+// Deprecated: Use [RequestIDKey.Value] instead.
+func RequestIDFromContext(ctx context.Context) RequestID {
+	return RequestIDKey.Value(ctx)
+}