public String getGatewayName(String serviceName, String envName) {
        return (envName != null ? envName + ManifestGenConstants.NAME_DELIMITER : "") + serviceName + ManifestGenConstants.NAME_DELIMITER + ManifestGenConstants.ISTIO + ManifestGenConstants.NAME_DELIMITER + ManifestGenConstants.GATEWAY;
    }
This class generates istio virtual service yaml.
manifest-generator/generator-services/src/main/java/io/hyscale/generator/services/builder/VirtualServiceBuilder.java