REGEXVAULT
Dev & Systems/Docker
ReDoS Checked

Docker Container Name Regex for PHP

/^[a-zA-Z0-9][a-zA-Z0-9_\-.]{0,253}$/

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What this pattern does

This page provides a well-structured, multi-part regular expression for matching docker container name, ported and verified for PHP. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your PHP project — whether you're validating in a Laravel validator, a WordPress plugin, or a standalone PHP script.

Php Implementation

Php
<?php
// Docker Container Name
// ReDoS-checked | RegexVault — Dev & Systems > Docker

define('DOCKER_CONTAINER_NAME_PATTERN', '/^[a-zA-Z0-9][a-zA-Z0-9_\-.]{0,253}$/');

function validate_docker_container_name(string $input): bool {
    return (bool) preg_match(DOCKER_CONTAINER_NAME_PATTERN, $input);
}

// Example
var_dump(validate_docker_container_name("my-container")); // bool(true)

Test Cases

Matches (Valid)
Rejects (Invalid)
my-container-container
webapp_1.container
db.primary/container
nginxcontainer name
app-server-01

When to use this pattern

This pattern is drawn from the Dev & Systems > Docker category and has been checked for ReDoS risk. That matters for PHP developers because especially relevant in PHP where PCRE backtracking limits can trigger silent failures on malicious input. 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

Container names in Docker Compose are auto-prefixed with the project name. Account for this prefix when referencing containers externally.

Technical Notes

Docker container names must be unique within a Docker daemon. Container names are used for DNS resolution within Docker networks.

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