CEL for HTTP header values

Signed-off-by: Norwin Schnyder <[email protected]>

Author: snorwin

apis/v1/httproute_types.go

@@ -612,9 +612,14 @@ type HTTPHeaderMatch struct {
 	Name HTTPHeaderName `json:"name"`
 
 	// Value is the value of HTTP Header to be matched.
+	// <gateway:experimental:description>
+	// Must consist of printable US-ASCII characters, optionally separated
+	// by single tabs or spaces. See: https://tools.ietf.org/html/rfc7230#section-3.2
+	// </gateway:experimental:description>
 	//
 	// +kubebuilder:validation:MinLength=1
 	// +kubebuilder:validation:MaxLength=4096
+	// <gateway:experimental:validation:XValidation:message="must only contain printable ASCII characters, optionally separated by single tabs or spaces",rule="self.matches('^[!-~]+([\\t ]?[!-~]+)*$')">
 	Value string `json:"value"`
 }
 
@@ -981,9 +986,14 @@ type HTTPHeader struct {
 	Name HTTPHeaderName `json:"name"`
 
 	// Value is the value of HTTP Header to be matched.
+	// <gateway:experimental:description>
+	// Must consist of printable US-ASCII characters, optionally separated
+	// by single tabs or spaces. See: https://tools.ietf.org/html/rfc7230#section-3.2
+	// </gateway:experimental:description>
 	//
 	// +kubebuilder:validation:MinLength=1
 	// +kubebuilder:validation:MaxLength=4096
+	// <gateway:experimental:validation:XValidation:message="must only contain printable ASCII characters, optionally separated by single tabs or spaces",rule="self.matches('^[!-~]+([\\t ]?[!-~]+)*$')">
 	Value string `json:"value"`
 }