jackwener/OpenCLI · error · ArgumentError

dockerhub image name is required (e.g. "nginx", "library/ngi

Error message

dockerhub image name is required (e.g. "nginx", "library/nginx", "bitnami/redis")

What it means

parseImage splits an image identifier into owner/name for Docker Hub API calls and requires a non-empty input. This ArgumentError is thrown when the image argument is missing, null, or whitespace-only after trimming/lowercasing.

Source

Thrown at clis/dockerhub/utils.js:42

    const n = typeof raw === 'number' ? raw : Number(raw);
    if (!Number.isInteger(n) || n <= 0) {
        throw new ArgumentError(`dockerhub ${label} must be a positive integer`);
    }
    if (n > maxValue) {
        throw new ArgumentError(`dockerhub ${label} must be <= ${maxValue}`);
    }
    return n;
}

/**
 * Split an image identifier into `{owner, name}`. Bare names use the implicit
 * `library` owner that Docker Hub uses for official images (`nginx` →
 * `library/nginx`).
 */
export function parseImage(input) {
    const raw = String(input ?? '').trim().toLowerCase();
    if (!raw) {
        throw new ArgumentError('dockerhub image name is required (e.g. "nginx", "library/nginx", "bitnami/redis")');
    }
    const slash = raw.indexOf('/');
    let owner;
    let name;
    if (slash >= 0) {
        owner = raw.slice(0, slash);
        name = raw.slice(slash + 1);
    }
    else {
        owner = 'library';
        name = raw;
    }
    if (!SLUG.test(owner) || !SLUG.test(name)) {
        throw new ArgumentError(
            `dockerhub image "${input}" is not a valid repository slug`,
            'Use lowercase letters / digits / "._-", optionally prefixed with "<owner>/".',
        );
    }

View on GitHub (pinned to 49907e53dc)

Solutions

1. Provide the image name, e.g. --image nginx
2. Use owner/name form for non-official images, e.g. --image bitnami/redis
3. Ensure the variable feeding the flag is non-empty

Example fix

// before
dockerhub info --image "$IMG"   # IMG unset
// after
: "${IMG:?IMG required}" && dockerhub info --image "$IMG"

const img = (args.image ?? '').trim(); if (!img) throw new Error('--image is required, e.g. nginx or bitnami/redis');

function hasImageArg(a) { return typeof a?.image === 'string' && a.image.trim() !== ''; }

try { await info(args); } catch (e) { if (e instanceof ArgumentError && e.message.includes('image name is required')) { console.error('Usage: --image <owner>/<name>'); process.exitCode = 2; } else throw e; }

When it happens

Trigger: Calling a dockerhub command that takes an image (e.g. dockerhub tags/info) without the --image flag; passing an empty string; an unset variable expanding to nothing.

Common situations: Scripts where the image name variable is empty; forgetting the positional/flag argument; pipeline configs with a placeholder image field never filled in.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• dockerhub image "${input}" is not a valid repository slug. U
• dockerhub image "${input}" name must be 2-255 chars
• dockerhub ${label} cannot be empty
• dockerhub ${label} must be a positive integer
• dockerhub ${label} must be <= ${maxValue}

AI-assisted analysis of jackwener/OpenCLI@49907e53dc (2026-08-29). Data as JSON: /api/errors/e87719c3f91c6e68. Report an issue: GitHub.