Docker Image Name (Official/Simple) Regex for JavaScript

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching docker image name (official/simple), ported and verified for JavaScript. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your JavaScript project — whether you're validating in an Express middleware, a Next.js API route, or a client-side form.

Javascript Implementation

// Docker Image Name (Official/Simple)
// ReDoS-safe | RegexVault — Dev & Systems > Docker

const dockerImageNameOfficialsimpleRegex = /^[a-z][a-z0-9\-._]{0,127}$/;

function validateDockerImageNameOfficialsimple(input: string): boolean {
  return dockerImageNameOfficialsimpleRegex.test(input);
}

// Example
console.log(validateDockerImageNameOfficialsimple("nginx")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Dev & Systems > Docker category and carries a ReDoS-safe certification. That matters for JavaScript developers because especially critical in long-running Node.js event loops where a ReDoS vulnerability can block the entire process. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Official images are lowercase. The maximum total image reference length is 255 chars. Underscores and dots are valid but hyphens cannot be the first character.