get-docker-registry-tags.py

#!/usr/bin/env python3
# License: MIT
# Author: github.com/danielhoherd
# Purpose: Return the latest image:tag for the given image, or optionally print a list of recent tags for the image.
from distutils.version import LooseVersion
from sys import stderr

import requests
import typer
from packaging import version


def main(image: str, list_tags: bool = typer.Option(False, help="Print a list of recent tags")):
    """Return the latest image:tag for the given image, or optionally print a
    list of recent tags for the image.

    You need to provide the bare image name that would be used in the
    docker pull command.
    """

    if ":" in image:
        try:
            image, tag = image.split(":")
            print(f'Stripped tag "{tag}" from input, continuing with "{image}"', file=stderr)
        except ValueError as e:
            print(f'Input error: "{image}" does not look like a docker image name', file=stderr)
            raise SystemExit(1) from e

    tags = get_tags_for_image(image)

    if list_tags:
        for tag in sorted(tags, key=LooseVersion):
            print(tag)
    else:
        newest = max(tags, key=LooseVersion)
        print(f"{image}:{newest}")


def get_tags_for_image(image):
    """Return a list of semver tags for the given image."""

    return get_tags_for_image_quay_io(image) if image.startswith("quay.io") else get_tags_for_image_docker_io(image)


def get_tags_for_image_docker_io(image):
    """Return a list of tags for docker hub image."""
    data = requests.get(f"https://index.docker.io/v1/repositories/{image.removeprefix('docker.io/')}/tags", timeout=30).json()
    if isinstance(data, str):
        raise SystemExit(f"ERROR: {data}")
    tags = {x["name"] for x in data if version.parse(x["name"]).release}
    if not tags:
        raise SystemExit(f"ERROR: No semver tags for image '{image}'")
    return tags


def get_tags_for_image_quay_io(image):
    """Return a list of tags for quay.io image."""
    resp = requests.get(f"https://quay.io/api/v1/repository/{image.removeprefix('quay.io/')}/tag?limit=100", timeout=30)
    data = resp.json()
    if not (200 <= resp.status_code < 300):
        raise SystemExit("ERROR: {status} {detail}".format(**data))
    tags = {x["name"] for x in data["tags"] if version.parse(x["name"]).release}
    if not tags:
        raise SystemExit(f"ERROR: No semver tags for image '{image}'")
    return tags


if __name__ == "__main__":
    typer.run(main)