Create request_id directive #1590 (#1711)

* Create request_id directive #1590

* Address Comments

* Fix TestListenerAddrEqual

* requestid: Add some tests

* Address Comments by tobya

* Address Comments

caddyhttp/httpserver/middleware.go

@@ -205,4 +205,7 @@ const (
 
 	// MitmCtxKey is the key for the result of MITM detection
 	MitmCtxKey caddy.CtxKey = "mitm"
+
+	// RequestIDCtxKey is the key for the U4 UUID value
+	RequestIDCtxKey caddy.CtxKey = "request_id"
 )

caddyhttp/httpserver/plugin.go

@@ -443,6 +443,7 @@ var directives = []string{
 	// services/utilities, or other directives that don't necessarily inject handlers
 	"startup",
 	"shutdown",
+	"requestid",
 	"realip", // github.com/captncraig/caddy-realip
 	"git",    // github.com/abiosoft/caddy-git
 

caddyhttp/httpserver/replacer.go

@@ -243,6 +243,9 @@ func (r *replacer) getSubstitution(key string) string {
 	case "{path_escaped}":
 		u, _ := r.request.Context().Value(OriginalURLCtxKey).(url.URL)
 		return url.QueryEscape(u.Path)
+	case "{request_id}":
+		reqid, _ := r.request.Context().Value(RequestIDCtxKey).(string)
+		return reqid
 	case "{rewrite_path}":
 		return r.request.URL.Path
 	case "{rewrite_path_escaped}":