refactor to address comments around how to print warnings

file/builder.go

@@ -602,13 +602,31 @@ func (b *stateBuilder) routes() {
 		return
 	}
 
+	unsupportedRoutes := []string{}
 	for _, r := range b.targetContent.Routes {
 		r := r
 		if err := b.ingestRoute(r); err != nil {
 			b.err = err
 			return
 		}
 	}
+
+	// check routes' paths format
+	if b.checkRoutePaths {
+		allRoutes, err := b.intermediate.Routes.GetAll()
+		if err != nil {
+			b.err = err
+			return
+		}
+		for _, r := range allRoutes {
+			if utils.HasPathsWithRegex300AndAbove(r.Route) {
+				unsupportedRoutes = append(unsupportedRoutes, *r.Route.ID)
+			}
+		}
+	}
+	if len(unsupportedRoutes) > 0 {
+		utils.PrintRouteRegexWarning()
+	}
 }
 
 func (b *stateBuilder) enterprise() {
@@ -799,10 +817,6 @@ func (b *stateBuilder) ingestRoute(r FRoute) error {
 		return err
 	}
 
-	if b.checkRoutePaths {
-		utils.CheckRoutePaths300AndAbove(r.Route)
-	}
-
 	// plugins for the route
 	var plugins []FPlugin
 	for _, p := range r.Plugins {

utils/utils.go

@@ -190,27 +190,35 @@ func ConfigFilesInDir(dir string) ([]string, error) {
 	return res, nil
 }
 
-// CheckRoutePaths300AndAbove checks routes' paths format and prints out
-// a warning if regex-like patters without the '~' prefix are found.
-func CheckRoutePaths300AndAbove(route kong.Route) {
-	pathsWarnings := []string{}
+// HasPathsWithRegex300AndAbove checks routes' paths format and returns true
+// if these math a regex-pattern without a '~' prefix.
+func HasPathsWithRegex300AndAbove(route kong.Route) bool {
 	for _, p := range route.Paths {
 		if strings.HasPrefix(*p, "~/") || !IsPathRegexLike(*p) {
 			continue
 		}
-		pathsWarnings = append(pathsWarnings, *p)
-	}
-	if len(pathsWarnings) > 0 {
-		cprint.UpdatePrintf(
-			"In Route '%s', a path with regular expression was detected.\n"+
-				"In Kong Gateway versions 3.0 and above, all paths that use regular expressions \n"+
-				"must be prefixed with a ~ character. Without the ~ prefix, regular expression \n"+
-				"based paths will not be matched and processed correctly. \n\n"+
-				"Please run the following command to upgrade your config: \n\n"+
-				"deck convert --from kong-gateway-2.x --to kong-gateway-3.x "+
-				"--input-file <config-file> --output-file <new-config-file>\n\n"+
-				"Please refer to the following document for further details:\n"+
-				"https://docs.konghq.com/deck/latest/3.0-upgrade.\n\n",
-			*route.ID)
+		return true
 	}
+	return false
+}
+
+// PrintRouteRegexWarning prints out a warning about 3.x routes' path usage.
+func PrintRouteRegexWarning() {
+	cprint.UpdatePrintf(
+		"unsupported routes' paths format with Kong version 3.0\n" +
+			"or above were detected.\n" +
+			"Please upgrade your configuration to account for 3.0\n" +
+			"breaking changes using the following command:\n\n" +
+			"deck convert --from kong-gateway-2.x --to kong-gateway-3.x\n\n" +
+			"This command performs the following changes:\n" +
+			"  - upgrade the `_format_version` value to `3.0`\n" +
+			"  - add the `~` prefix to all routes' paths containing a regex-pattern\n\n" +
+			"These changes may not be correct or exhaustive enough.\n" +
+			"It is strongly recommended to perform a manual audit\n" +
+			"of the updated configuration file before applying\n" +
+			"the configuration in production. Incorrect changes will result in\n" +
+			"unintended traffic routing by Kong Gateway.\n\n" +
+
+			"For more information about this and related changes,\n" +
+			"please visit: https://docs.konghq.com/deck/latest/3.0-upgrade\n\n")
 }

validate/validate.go

@@ -186,7 +186,13 @@ func (v *Validator) Validate(kongVersion semver.Version) []error {
 
 func validate3xRoutes(routes *state.RoutesCollection) {
 	results, _ := routes.GetAll()
+	unsupportedRoutes := []string{}
 	for _, r := range results {
-		utils.CheckRoutePaths300AndAbove(r.Route)
+		if utils.HasPathsWithRegex300AndAbove(r.Route) {
+			unsupportedRoutes = append(unsupportedRoutes, *r.Route.ID)
+		}
+	}
+	if len(unsupportedRoutes) > 0 {
+		utils.PrintRouteRegexWarning()
 	}
 }