cull-kernels.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "aeaec312",
   "metadata": {},
   "outputs": [],
   "source": [
    "import json\n",
    "import os\n",
    "import subprocess\n",
    "\n",
    "import requests\n",
    "\n",
    "\n",
    "# API token is always available in the jupyterhub environment\n",
    "\n",
    "token = os.environ[\"JUPYTERHUB_API_TOKEN\"]\n",
    "# create a requests Session object with our auth token\n",
    "s = requests.Session()\n",
    "s.headers = {\"Authorization\": f\"token {token}\"}"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "f77a894b",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[{'base_url': '/user/test-1/',\n",
       "  'hostname': '127.0.0.1',\n",
       "  'notebook_dir': '/private/tmp/test-1',\n",
       "  'password': False,\n",
       "  'pid': 94573,\n",
       "  'port': 50632,\n",
       "  'secure': False,\n",
       "  'sock': '',\n",
       "  'token': '',\n",
       "  'url': 'http://127.0.0.1:50632/user/test-1/'}]"
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# get the running server(s) from `jupyter notebook list`\n",
    "p = subprocess.run([\"jupyter\", \"notebook\", \"list\", \"--json\"], capture_output=True, text=True)\n",
    "servers = []\n",
    "for line in p.stdout.splitlines():\n",
    "    servers.append(json.loads(line))\n",
    "servers"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "dfa5e287",
   "metadata": {},
   "outputs": [],
   "source": [
    "# assume one server for now\n",
    "# can select by comparing base_url to $JUPYTERHUB_SERVICE_PREFIX\n",
    "server = servers[0]\n",
    "jupyter_api = f\"{server['url']}api\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "650901b3",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[{'id': '42481fdd-c6a8-4e69-ae9f-c2c2b6b2c233',\n",
       "  'path': 'cull-kernels.ipynb',\n",
       "  'name': 'cull-kernels.ipynb',\n",
       "  'type': 'notebook',\n",
       "  'kernel': {'id': '1e884864-3de1-4cad-a1f1-8f4a055888e4',\n",
       "   'name': 'python3',\n",
       "   'last_activity': '2021-04-27T09:41:09.657388Z',\n",
       "   'execution_state': 'busy',\n",
       "   'connections': 2},\n",
       "  'notebook': {'path': 'cull-kernels.ipynb', 'name': 'cull-kernels.ipynb'}},\n",
       " {'id': '812efebf-4221-41a8-ab3e-524d197e0909',\n",
       "  'path': 'still-connected.ipynb',\n",
       "  'name': 'still-connected.ipynb',\n",
       "  'type': 'notebook',\n",
       "  'kernel': {'id': '751818eb-246d-45bc-8de8-d0a13c1777e1',\n",
       "   'name': 'python3',\n",
       "   'last_activity': '2021-04-27T09:41:01.450770Z',\n",
       "   'execution_state': 'idle',\n",
       "   'connections': 1},\n",
       "  'notebook': {'path': 'still-connected.ipynb',\n",
       "   'name': 'still-connected.ipynb'}},\n",
       " {'id': '75e31fcc-948b-4021-adb1-af3bdbfe8630',\n",
       "  'path': 'idle-notebook.ipynb',\n",
       "  'name': 'idle-notebook.ipynb',\n",
       "  'type': 'notebook',\n",
       "  'kernel': {'id': 'ef4bd7f8-ea09-45fe-bfdb-01abcee02bdb',\n",
       "   'name': 'python3',\n",
       "   'last_activity': '2021-04-27T09:40:45.354849Z',\n",
       "   'execution_state': 'idle',\n",
       "   'connections': 0},\n",
       "  'notebook': {'path': 'idle-notebook.ipynb', 'name': 'idle-notebook.ipynb'}}]"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# List sessions using jupyter REST API\n",
    "\n",
    "sessions = s.get(f\"{jupyter_api}/sessions\").json()\n",
    "\n",
    "# sort by activity\n",
    "# last_activity is ISO8601 strings, sortable without parsing\n",
    "sessions = sorted(sessions, key=lambda s: s[\"kernel\"][\"last_activity\"], reverse=True)\n",
    "sessions"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "5809499d",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Not shutting down most recently active session: cull-kernels.ipynb\n",
      "Not shutting down kernel with 1 connections: still-connected.ipynb\n",
      "Shutting down session idle-notebook.ipynb idle since 2021-04-27T09:40:45.354849Z\n"
     ]
    }
   ],
   "source": [
    "# don't shutdown the most recently active kernel, but shut down all others\n",
    "if sessions:\n",
    "    print(f\"Not shutting down most recently active session: {sessions[0]['name']}\")\n",
    "\n",
    "for session in sessions[1:]:\n",
    "    kernel = session['kernel']\n",
    "    name = session['name']\n",
    "    if kernel['execution_state'] == 'busy':\n",
    "        print(f\"Not shutting down busy kernel for {name}\")\n",
    "        continue\n",
    "    if kernel['connections']:\n",
    "        print(f\"Not shutting down kernel with {kernel['connections']} connections: {name}\")\n",
    "        continue\n",
    "    print(f\"Shutting down session {name} idle since {kernel['last_activity']}\")\n",
    "    r = s.delete(f\"{jupyter_api}/sessions/{session['id']}\")\n",
    "    r.raise_for_status()"
   ]
  }
 ],
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   "display_name": "Python 3 (ipykernel)",
   "language": "python",
   "name": "python3"
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    "name": "ipython",
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   "file_extension": ".py",
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