Docker Image Reference Regex Pattern

Live Regex Tester

Pattern Breakdown

Code Examples

const regex = /^([a-z0-9._-]+\/)?[a-z0-9._-]+(:[a-zA-Z0-9._-]+)?(@sha256:[a-f0-9]{64})?$/;
const test = "nginx:latest";
console.log(regex.test(test)); // true

// Extract matches
const matches = test.match(regex);
console.log(matches);

import re

pattern = r'^([a-z0-9._-]+\/)?[a-z0-9._-]+(:[a-zA-Z0-9._-]+)?(@sha256:[a-f0-9]{64})?$'
test = "nginx:latest"
match = re.search(pattern, test)
print(match)  # Found!

package main

import (
    "fmt"
    "regexp"
)

func main() {
    re := regexp.MustCompile(`^([a-z0-9._-]+\/)?[a-z0-9._-]+(:[a-zA-Z0-9._-]+)?(@sha256:[a-f0-9]{64})?$`)
    fmt.Println(re.MatchString("nginx:latest")) // true
}

Common Use Cases

Match Examples

About the Docker Image Reference Regex

Validates Docker image references with optional registry, tag, and digest. Used in Dockerfiles and compose files.

Regular expressions (regex) are powerful pattern matching tools used across virtually all programming languages. The docker image reference pattern is classified as intermediate difficulty in the data formats category. It works in all major programming languages.

When using this regex, always consider edge cases and test thoroughly with real-world data. Use the interactive tester above to validate the pattern against your specific inputs before deploying to production.

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