Identifiers

Kubernetes Pod Name (RFC 1123)

Validate Kubernetes pod names per the RFC 1123 DNS label rules — lowercase, ≤63 chars, no leading/trailing hyphen.

Available in

JavaScript / ECMAScript code

jsJavaScript

const re = new RegExp("^[a-z0-9](?:[a-z0-9\\-]{0,61}[a-z0-9])?$", "");
const input = "nginx-deployment-66b6c48dd5-abcd1";
const matches = [...input.matchAll(re)];
console.log(matches.map(m => m[0]));

Uses `String.prototype.matchAll` for global iteration (Node 12+ / all modern browsers).

Python (re) code

pyPython

import re

pattern = re.compile(r"^[a-z0-9](?:[a-z0-9\-]{0,61}[a-z0-9])?$")
input_text = "nginx-deployment-66b6c48dd5-abcd1"
for m in pattern.finditer(input_text):
    print(m.group(0))

Stdlib `re` module — no third-party dependency. Works on Python 3.6+.

Go (RE2) code

goGo

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`^[a-z0-9](?:[a-z0-9\-]{0,61}[a-z0-9])?$`)
	input := `nginx-deployment-66b6c48dd5-abcd1`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}

Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.

Pattern

regexengine-agnostic

^[a-z0-9](?:[a-z0-9\-]{0,61}[a-z0-9])?$

Raw source: ^[a-z0-9](?:[a-z0-9\-]{0,61}[a-z0-9])?$

How it works

Stricter than the general hostname pattern: pod names must be LOWERCASE only (per K8s spec). [a-z0-9] for first char. (?:[a-z0-9\-]{0,61}[a-z0-9])? optionally allows up to 61 more chars ending in a non-hyphen. Total length ≤63 chars per RFC 1123 label limits.