[TOC] ### **规范定义** 我们先介绍[四种规范的定义](https://github.com/kubernetes/community/blob/master/contributors/design-proposals/architecture/identifiers.md#definitions)： * [rfc1035](http://www.ietf.org/rfc/rfc1035.txt)/[rfc1123](http://www.ietf.org/rfc/rfc1123.txt)`label`(DNS\_LABEL): An alphanumeric (a-z, and 0-9) string, with a maximum length of 63 characters, with the '-' character allowed anywhere except the first or last character, suitable for use as a hostname or segment in a domain name. （中文意思大致为，`DNS_LABEL`只能：（1）由小写字母、数字、中划线组成（2）中划线不能出现在第一位与最后一位（3）总长度不超过63个字符 * [rfc1035](http://www.ietf.org/rfc/rfc1035.txt)/[rfc1123](http://www.ietf.org/rfc/rfc1123.txt)`subdomain`(DNS\_SUBDOMAIN): One or more lowercase rfc1035/rfc1123 labels separated by '.' with a maximum length of 253 characters. （中文意思大致为，`DNS_SUBDOMAIN`由：（1）一个或多个`DNS_LABEL`组成（2）如果由多个`DNS_LABEL`组成，`DNS_LABEL`之间由`.`号隔开（3）总长度不超过253个字符 * [rfc4122](http://www.ietf.org/rfc/rfc4122.txt)`universally unique identifier`(UUID): A 128 bit generated value that is extremely unlikely to collide across time and space and requires no central coordination. * [rfc6335](https://tools.ietf.org/rfc/rfc6335.txt)`port name`(IANA\_SVC\_NAME): An alphanumeric (a-z, and 0-9) string, with a maximum length of 15 characters, with the '-' character allowed anywhere except the first or the last character or adjacent to another '-' character, it must contain at least a (a-z) character. ### **K8S的命名规范的设计** 接下来，我们再来看[K8S的命名规范的设计](https://github.com/kubernetes/community/blob/master/contributors/design-proposals/architecture/identifiers.md#general-design) * K8S对象的名字：要符合`DNS_SUBDOMAIN` * K8S命名空间：要符合`DNS_LABEL` ### **参考** * https://github.com/kubernetes/community/blob/master/contributors/design-proposals/architecture/identifiers.md