Request ID Logging (#1087)

* Add RequestID to the RequestScope

* Expose RequestID to auth & request loggers

* Use the RequestID in templated HTML pages

* Allow customizing the RequestID header

* Document new Request ID support

* Add more cases to scope/requestID tests

* Split Get vs Generate RequestID funtionality

* Add {{.RequestID}} to the request logger tests

* Move RequestID management to RequestScope

* Use HTML escape instead of sanitization for Request ID rendering

pkg/requests/util/util.go

@@ -6,10 +6,16 @@ import (
 	middlewareapi "github.com/oauth2-proxy/oauth2-proxy/v7/pkg/apis/middleware"
 )
 
+const (
+	XForwardedProto = "X-Forwarded-Proto"
+	XForwardedHost  = "X-Forwarded-Host"
+	XForwardedURI   = "X-Forwarded-Uri"
+)
+
 // GetRequestProto returns the request scheme or X-Forwarded-Proto if present
 // and the request is proxied.
 func GetRequestProto(req *http.Request) string {
-	proto := req.Header.Get("X-Forwarded-Proto")
+	proto := req.Header.Get(XForwardedProto)
 	if !IsProxied(req) || proto == "" {
 		proto = req.URL.Scheme
 	}
@@ -19,7 +25,7 @@ func GetRequestProto(req *http.Request) string {
 // GetRequestHost returns the request host header or X-Forwarded-Host if
 // present and the request is proxied.
 func GetRequestHost(req *http.Request) string {
-	host := req.Header.Get("X-Forwarded-Host")
+	host := req.Header.Get(XForwardedHost)
 	if !IsProxied(req) || host == "" {
 		host = req.Host
 	}
@@ -29,7 +35,7 @@ func GetRequestHost(req *http.Request) string {
 // GetRequestURI return the request URI or X-Forwarded-Uri if present and the
 // request is proxied.
 func GetRequestURI(req *http.Request) string {
-	uri := req.Header.Get("X-Forwarded-Uri")
+	uri := req.Header.Get(XForwardedURI)
 	if !IsProxied(req) || uri == "" {
 		// Use RequestURI to preserve ?query
 		uri = req.URL.RequestURI()