Proof of concept interaction with the Google Container Registry.

httpx_gcr.ipynb

urllib_gcr.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%load_ext lab_black"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import json\n",
    "import logging\n",
    "from urllib.parse import urljoin\n",
    "from urllib.error import HTTPError\n",
    "from urllib.request import build_opener\n",
    "from urllib.parse import urlencode, urljoin, urlsplit, urlunsplit"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "logging.basicConfig(level=\"DEBUG\")\n",
    "logging.getLogger(\"blib2to3\").setLevel(logging.WARNING)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "image = \"\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "service = \"gcr.io\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "authentication_url = \"https://gcr.io/v2/token\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "registry_url = \"https://gcr.io\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "output = !gcloud auth print-access-token\n",
    "token = output[0]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "auth_opener = build_opener()\n",
    "auth_opener.addheaders.extend(\n",
    "    [\n",
    "        (\"Accept\", \"application/vnd.docker.distribution.manifest.v2+json\"),\n",
    "        (\"Authorization\", f\"Bearer {token}\"),\n",
    "    ]\n",
    ")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "parts = urlsplit(authentication_url)\n",
    "with auth_opener.open(\n",
    "    urlunsplit(\n",
    "        parts._replace(\n",
    "            query=urlencode({\"scope\": f\"repository:{image}:pull\", \"service\": service})\n",
    "        )\n",
    "    )\n",
    ") as response:\n",
    "    print(response.geturl())\n",
    "    print(response.status, response.reason)\n",
    "    data = json.loads(response.read())\n",
    "access_token = data[\"token\"]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "opener = build_opener()\n",
    "opener.addheaders.extend(\n",
    "    [\n",
    "        (\"Accept\", \"application/vnd.docker.distribution.manifest.v2+json\"),\n",
    "        (\"Authorization\", f\"Bearer {access_token}\"),\n",
    "    ]\n",
    ")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "parts = urlsplit(registry_url)\n",
    "with opener.open(urlunsplit(parts._replace(path=\"/v2/\"))) as response:\n",
    "    print(response.geturl())\n",
    "    print(response.status, response.reason)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "digest = \"\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "This call fails with 401 Unauthorized yet I can even open the requested URL in my browser and it works..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "parts = urlsplit(registry_url)\n",
    "try:\n",
    "    with opener.open(\n",
    "        urlunsplit(parts._replace(path=f\"/v2/{image}/blobs/{digest}\"))\n",
    "    ) as response:\n",
    "        print(response.geturl())\n",
    "        print(response.status, response.reason)\n",
    "        data = json.loads(response.read())\n",
    "except HTTPError as error:\n",
    "    print(error.geturl())\n",
    "    print(error.status, error.reason)\n",
    "    data = error.read()\n",
    "data"
   ]
  }
 ],
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