feat: Exclude comments from CRD generation but not from go struct definition (#3321)

* implemented logic for excluding comments from CRD generation

* edited regex pattern

* added a comment for excludeFromCRD tag

* added excludeFromCRD tag to AbsoluteURI

Author: Devaansh-Kumar

apis/v1/shared_types.go

@@ -542,7 +542,7 @@ type PreciseHostname string
 // scheme (e.g., "http" or "spiffe") and a scheme-specific-part.  URIs that
 // include an authority MUST include a fully qualified domain name or
 // IP address as the host.
-
+// <gateway:util:excludeFromCRD> The below regex is taken from the regex section in RFC 3986 with a slight modification to enforce a full URI and not relative. </gateway:util:excludeFromCRD>
 // +kubebuilder:validation:MinLength=1
 // +kubebuilder:validation:MaxLength=253
 // +kubebuilder:validation:Pattern=`^(([^:/?#]+):)(//([^/?#]*))([^?#]*)(\?([^#]*))?(#(.*))?`

pkg/generator/main.go

@@ -222,6 +222,21 @@ func gatewayTweaks(channel string, props map[string]apiext.JSONSchemaProps) map[
 			jsonProps.Description = strings.ReplaceAll(jsonProps.Description, endTag, "")
 		}
 
+		// Comments within "gateway:util:excludeFromCRD" tag is not included in the generated CRD and all trailing \n operators before
+		// and after the tags are removed and replaced with three \n operators.
+		startTag = "<gateway:util:excludeFromCRD>"
+		endTag = "</gateway:util:excludeFromCRD>"
+		regexPattern = `\n*` + regexp.QuoteMeta(startTag) + `(?s:(.*?))` + regexp.QuoteMeta(endTag) + `\n*`
+		if strings.Contains(jsonProps.Description, "<gateway:util:excludeFromCRD>") {
+			re := regexp.MustCompile(regexPattern)
+			match := re.FindStringSubmatch(jsonProps.Description)
+			if len(match) != 2 {
+				log.Fatalf("Invalid <gateway:util:excludeFromCRD> tag for %s", name)
+			}
+			modifiedDescription := re.ReplaceAllString(jsonProps.Description, "\n\n\n")
+			jsonProps.Description = modifiedDescription
+		}
+
 		if numValid < numExpressions {
 			fmt.Printf("Description: %s\n", jsonProps.Description)
 			log.Fatalf("Found %d Gateway validation expressions, but only %d were valid", numExpressions, numValid)