Bump to 2.0.0rc1

use tbump to tag versions

.github/workflows/support-bot.yml

@@ -0,0 +1,31 @@
+# https://github.com/dessant/support-requests
+name: "Support Requests"
+
+on:
+  issues:
+    types: [labeled, unlabeled, reopened]
+
+permissions:
+  issues: write
+
+jobs:
+  action:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: dessant/support-requests@v2
+        with:
+          github-token: ${{ github.token }}
+          support-label: "support"
+          issue-comment: |
+            Hi there @{issue-author} :wave:!
+
+            I closed this issue because it was labelled as a support question.
+
+            Please help us organize discussion by posting this on the http://discourse.jupyter.org/ forum.
+
+            Our goal is to sustain a positive experience for both users and developers. We use GitHub issues for specific discussions related to changing a repository's content, and let the forum be where we can more generally help and inspire each other.
+
+            Thanks you for being an active member of our community! :heart:
+          close-issue: true
+          lock-issue: false
+          issue-lock-reason: "off-topic"

.github/workflows/test.yml

@@ -14,8 +14,28 @@ on:
 env:
   # UTF-8 content may be interpreted as ascii and causes errors without this.
   LANG: C.UTF-8
+  PYTEST_ADDOPTS: "--verbose --color=yes"
 
 jobs:
+  rest-api:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v2
+      - name: Validate REST API
+        uses: char0n/swagger-editor-validate@182d1a5d26ff5c2f4f452c43bd55e2c7d8064003
+        with:
+          definition-file: docs/source/_static/rest-api.yml
+
+      - uses: actions/setup-python@v2
+        with:
+          python-version: "3.9"
+      # in addition to the doc requirements
+      # the docs *tests* require pre-commit and pytest
+      - run: |
+          pip install -r docs/requirements.txt pytest pre-commit -e .
+      - run: |
+          pytest docs/
+
   # Run "pytest jupyterhub/tests" in various configurations
   pytest:
     runs-on: ubuntu-20.04
@@ -38,9 +58,9 @@ jobs:
         #   Tests everything when JupyterHub works against a dedicated mysql or
         #   postgresql server.
         #
-        # jupyter_server:
+        # nbclassic:
         #   Tests everything when the user instances are started with
-        #   jupyter_server instead of notebook.
+        #   notebook instead of jupyter_server.
         #
         # ssl:
         #   Tests everything using internal SSL connections instead of
@@ -48,7 +68,7 @@ jobs:
         #
         # main_dependencies:
         #   Tests everything when the we use the latest available dependencies
-        #   from: ipytraitlets.
+        #   from: traitlets.
         #
         # NOTE: Since only the value of these parameters are presented in the
         #       GitHub UI when the workflow run, we avoid using true/false as
@@ -56,6 +76,7 @@ jobs:
         include:
           - python: "3.6"
             oldest_dependencies: oldest_dependencies
+            nbclassic: nbclassic
           - python: "3.6"
             subdomain: subdomain
           - python: "3.7"
@@ -65,7 +86,7 @@ jobs:
           - python: "3.8"
             db: postgres
           - python: "3.8"
-            jupyter_server: jupyter_server
+            nbclassic: nbclassic
           - python: "3.9"
             main_dependencies: main_dependencies
 
@@ -130,9 +151,9 @@ jobs:
           if [ "${{ matrix.main_dependencies }}" != "" ]; then
               pip install git+https://github.com/ipython/traitlets#egg=traitlets --force
           fi
-          if [ "${{ matrix.jupyter_server }}" != "" ]; then
+          if [ "${{ matrix.nbclassic }}" != "" ]; then
-              pip uninstall notebook --yes
+              pip uninstall jupyter_server --yes
-              pip install jupyter_server
+              pip install notebook
           fi
           if [ "${{ matrix.db }}" == "mysql" ]; then
               pip install mysql-connector-python
@@ -181,10 +202,8 @@ jobs:
           fi
 
       - name: Run pytest
-        # FIXME: --color=yes explicitly set because:
-        #        https://github.com/actions/runner/issues/241
         run: |
-          pytest -v --maxfail=2 --color=yes --cov=jupyterhub jupyterhub/tests
+          pytest --maxfail=2 --cov=jupyterhub jupyterhub/tests
       - name: Run yarn jest test
         run: |
           cd jsx && yarn && yarn test
@@ -194,7 +213,7 @@ jobs:
 
   docker-build:
     runs-on: ubuntu-20.04
-    timeout-minutes: 10
+    timeout-minutes: 20
 
     steps:
       - uses: actions/checkout@v2

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/asottile/pyupgrade
-    rev: v2.26.0
+    rev: v2.29.0
     hooks:
       - id: pyupgrade
         args:
@@ -10,15 +10,15 @@ repos:
     hooks:
       - id: reorder-python-imports
   - repo: https://github.com/psf/black
-    rev: 21.8b0
+    rev: 21.9b0
     hooks:
       - id: black
   - repo: https://github.com/pre-commit/mirrors-prettier
-    rev: v2.4.0
+    rev: v2.4.1
     hooks:
       - id: prettier
   - repo: https://github.com/PyCQA/flake8
-    rev: "3.9.2"
+    rev: "4.0.1"
     hooks:
       - id: flake8
   - repo: https://github.com/pre-commit/pre-commit-hooks

CHECKLIST-Release.md

@@ -1,26 +0,0 @@
-# Release checklist
-
-- [ ] Upgrade Docs prior to Release
-
-  - [ ] Change log
-  - [ ] New features documented
-  - [ ] Update the contributor list - thank you page
-
-- [ ] Upgrade and test Reference Deployments
-
-- [ ] Release software
-
-  - [ ] Make sure 0 issues in milestone
-  - [ ] Follow release process steps
-  - [ ] Send builds to PyPI (Warehouse) and Conda Forge
-
-- [ ] Blog post and/or release note
-
-- [ ] Notify users of release
-
-  - [ ] Email Jupyter and Jupyter In Education mailing lists
-  - [ ] Tweet (optional)
-
-- [ ] Increment the version number for the next release
-
-- [ ] Update roadmap

README.md

@@ -56,9 +56,11 @@ Basic principles for operation are:
   servers.
 
 JupyterHub also provides a
-[REST API](https://petstore3.swagger.io/?url=https://raw.githubusercontent.com/jupyter/jupyterhub/HEAD/docs/rest-api.yml#/default)
+[REST API][]
 for administration of the Hub and its users.
 
+[rest api]: https://juptyerhub.readthedocs.io/en/latest/reference/rest-api.html
+
 ## Installation
 
 ### Check prerequisites
@@ -239,7 +241,7 @@ You can also talk with us on our JupyterHub [Gitter](https://gitter.im/jupyterhu
 - [Reporting Issues](https://github.com/jupyterhub/jupyterhub/issues)
 - [JupyterHub tutorial](https://github.com/jupyterhub/jupyterhub-tutorial)
 - [Documentation for JupyterHub](https://jupyterhub.readthedocs.io/en/latest/) | [PDF (latest)](https://media.readthedocs.org/pdf/jupyterhub/latest/jupyterhub.pdf) | [PDF (stable)](https://media.readthedocs.org/pdf/jupyterhub/stable/jupyterhub.pdf)
-- [Documentation for JupyterHub's REST API](https://petstore3.swagger.io/?url=https://raw.githubusercontent.com/jupyter/jupyterhub/HEAD/docs/rest-api.yml#/default)
+- [Documentation for JupyterHub's REST API][rest api]
 - [Documentation for Project Jupyter](http://jupyter.readthedocs.io/en/latest/index.html) | [PDF](https://media.readthedocs.org/pdf/jupyter/latest/jupyter.pdf)
 - [Project Jupyter website](https://jupyter.org)
 - [Project Jupyter community](https://jupyter.org/community)

RELEASE.md

@@ -0,0 +1,50 @@
+# How to make a release
+
+`jupyterhub` is a package [available on
+PyPI](https://pypi.org/project/jupyterhub/) and
+[conda-forge](https://conda-forge.org/).
+These are instructions on how to make a release on PyPI.
+The PyPI release is done automatically by CI when a tag is pushed.
+
+For you to follow along according to these instructions, you need:
+
+- To have push rights to the [jupyterhub GitHub
+  repository](https://github.com/jupyterhub/jupyterhub).
+
+## Steps to make a release
+
+1. Checkout main and make sure it is up to date.
+
+   ```shell
+   ORIGIN=${ORIGIN:-origin} # set to the canonical remote, e.g. 'upstream' if 'origin' is not the official repo
+   git checkout main
+   git fetch $ORIGIN main
+   git reset --hard $ORIGIN/main
+   ```
+
+1. Make sure `docs/source/changelog.md` is up-to-date.
+   [github-activity][] can help with this.
+
+1. Update the version with `tbump`.
+   You can see what will happen without making any changes with `tbump --dry-run ${VERSION}`
+
+   ```shell
+   tbump ${VERSION}
+   ```
+
+   This will tag and publish a release,
+   which will be finished on CI.
+
+1. Reset the version back to dev, e.g. `2.1.0.dev` after releasing `2.0.0`
+
+   ```shell
+   tbump --no-tag ${NEXT_VERSION}.dev
+   ```
+
+1. Following the release to PyPI, an automated PR should arrive to
+   [conda-forge/jupyterhub-feedstock][],
+   check for the tests to succeed on this PR and then merge it to successfully
+   update the package for `conda` on the conda-forge channel.
+
+[github-activity]: https://github.com/choldgraf/github-activity
+[conda-forge/jupyterhub-feedstock]: https://github.com/conda-forge/jupyterhub-feedstock

SECURITY.md

@@ -0,0 +1,5 @@
+# Reporting a Vulnerability
+
+If you believe you’ve found a security vulnerability in a Jupyter
+project, please report it to security@ipython.org. If you prefer to
+encrypt your security reports, you can use [this PGP public key](https://jupyter-notebook.readthedocs.io/en/stable/_downloads/1d303a645f2505a8fd283826fafc9908/ipython_security.asc).

dev-requirements.txt

@@ -7,13 +7,14 @@ codecov
 coverage
 cryptography
 html5lib  # needed for beautifulsoup
+jupyterlab >=3
 mock
-notebook
 pre-commit
 pytest>=3.3
 pytest-asyncio
 pytest-cov
 requests-mock
+tbump
 # blacklist urllib3 releases affected by https://github.com/urllib3/urllib3/issues/1683
 # I *think* this should only affect testing, not production
 urllib3!=1.25.4,!=1.25.5

docs/Makefile

@@ -53,14 +53,6 @@ help:
 clean:
 	rm -rf $(BUILDDIR)/*
 
-node_modules: package.json
-	npm install && touch node_modules
-
-rest-api: source/_static/rest-api/index.html
-
-source/_static/rest-api/index.html: rest-api.yml node_modules
-	npm run rest-api
-
 metrics: source/reference/metrics.rst
 
 source/reference/metrics.rst: generate-metrics.py
@@ -71,7 +63,7 @@ scopes: source/rbac/scope-table.md
 source/rbac/scope-table.md: source/rbac/generate-scope-table.py
 	python3 source/rbac/generate-scope-table.py
 
-html: rest-api metrics scopes
+html: metrics scopes
 	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
 	@echo
 	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."

docs/package.json

@@ -1,14 +0,0 @@
-{
-  "name": "jupyterhub-docs-build",
-  "version": "0.8.0",
-  "description": "build JupyterHub swagger docs",
-  "scripts": {
-    "rest-api": "bootprint openapi ./rest-api.yml source/_static/rest-api"
-  },
-  "author": "",
-  "license": "BSD-3-Clause",
-  "devDependencies": {
-    "bootprint": "^1.0.0",
-    "bootprint-openapi": "^1.0.0"
-  }
-}

docs/requirements.txt

@@ -1,9 +1,7 @@
 -r ../requirements.txt
 
 alabaster_jupyterhub
-# Temporary fix of #3021. Revert back to released autodoc-traits when
+autodoc-traits
-# 0.1.0 released.
-https://github.com/jupyterhub/autodoc-traits/archive/d22282c1c18c6865436e06d8b329c06fe12a07f8.zip
 myst-parser
 pydata-sphinx-theme
 pytablewriter>=0.56

docs/source/_static/custom.css

@@ -2,3 +2,9 @@
 .navbar-brand {
   height: 4rem !important;
 }
+
+/* hide redundant funky-formatted swagger-ui version */
+
+.swagger-ui .info .title small {
+  display: none !important;
+}

docs/source/_static/rest-api.yml

@@ -1,9 +1,11 @@
-# see me at: https://petstore3.swagger.io/?url=https://raw.githubusercontent.com/jupyterhub/jupyterhub/HEAD/docs/rest-api.yml#/default
+# see me at: https://jupyterhub.readthedocs.io/en/latest/reference/rest-api.html
 swagger: "2.0"
 info:
   title: JupyterHub
   description: The REST API for JupyterHub
-  version: 1.4.0
+  # version should match jupyterhub/_version.py
+  # `make scopes` ensures this is in sync
+  version: 2.0.0rc1
   license:
     name: BSD-3-Clause
 schemes: [http, https]
@@ -15,14 +17,17 @@ securityDefinitions:
   oauth2:
     type: oauth2
     flow: accessCode
-    authorizationUrl: "/hub/api/oauth2/authorize" # what are the absolute URIs here? is oauth2 correct here or shall we use just authorizations?
+    # these must be absolute until we update to openapi 3
-    tokenUrl: "/hub/api/oauth2/token"
+    authorizationUrl: "https://hub.example/hub/api/oauth2/authorize"
+    tokenUrl: "https://hub.example/hub/api/oauth2/token"
     scopes: # Generated based on scope table in jupyterhub/scopes.py
       (no_scope): Identify the owner of the requesting entity.
       self:
         The user’s own resources _(metascope for users, resolves to (no_scope)
         for services)_
-      all: Everything that the token-owning entity can access _(metascope for tokens)_
+      inherit:
+        Everything that the token-owning entity can access _(metascope for
+        tokens)_
       admin:users:
         Read, write, create and delete users and their authentication state,
         not including their servers or tokens.
@@ -30,6 +35,8 @@ securityDefinitions:
       users:
         Read and write permissions to user models (excluding servers, tokens
         and authentication state).
+      delete:users: Delete users.
+      list:users: List users, including at least their names.
       read:users:
         Read user models (excluding including servers, tokens and authentication
         state).
@@ -47,14 +54,18 @@ securityDefinitions:
       read:servers:
         Read users’ names and their server models (excluding the server
         state).
+      delete:servers: Stop and delete users' servers.
       tokens: Read, write, create and delete user tokens.
       read:tokens: Read user tokens.
       admin:groups: Read and write group information, create and delete groups.
       groups:
         Read and write group information, including adding/removing users to/from
         groups.
+      list:groups: List groups, including at least their names.
       read:groups: Read group models.
       read:groups:name: Read group names.
+      delete:groups: Delete groups.
+      list:services: List services, including at least their names.
       read:services: Read service models.
       read:services:name: Read service names.
       read:hub: Read detailed information about the Hub.
@@ -174,7 +185,7 @@ paths:
             If unspecified, return all users.
         - name: limit
           in: query
-          requred: false
+          required: false
           type: number
           description: |
             Return a finite number of users.
@@ -779,7 +790,7 @@ paths:
             If unspecified, return all routes.
         - name: limit
           in: query
-          requred: false
+          required: false
           type: number
           description: |
             Return a finite number of routes.
@@ -870,7 +881,7 @@ paths:
       summary: Identify a user or service from an API token
       security:
         - oauth2:
-            - (noscope)
+            - (no_scope)
       parameters:
         - name: token
           in: path

docs/source/api/index.rst

@@ -17,11 +17,6 @@ information on:
 - making an API request programmatically using the requests library
 - learning more about JupyterHub's API
 
-The same JupyterHub API spec, as found here, is available in an interactive form
-`here (on swagger's petstore) <https://petstore3.swagger.io/?url=https://raw.githubusercontent.com/jupyterhub/jupyterhub/HEAD/docs/rest-api.yml#!/default>`__.
-The `OpenAPI Initiative`_ (fka Swagger™) is a project used to describe
-and document RESTful APIs.
-
 JupyterHub API Reference:
 
 .. toctree::

docs/source/conf.py

@@ -215,7 +215,7 @@ if on_rtd:
     # build both metrics and rest-api, since RTD doesn't run make
     from subprocess import check_call as sh
 
-    sh(['make', 'metrics', 'rest-api', 'scopes'], cwd=docs)
+    sh(['make', 'metrics', 'scopes'], cwd=docs)
 
 # -- Spell checking -------------------------------------------------------
 

docs/source/index.rst

@@ -43,7 +43,7 @@ JupyterHub performs the following functions:
   notebook servers
 
 For convenient administration of the Hub, its users, and services,
-JupyterHub also provides a `REST API`_.
+JupyterHub also provides a :doc:`REST API <reference/rest-api>`.
 
 The JupyterHub team and Project Jupyter value our community, and JupyterHub
 follows the Jupyter `Community Guides <https://jupyter.readthedocs.io/en/latest/community/content-community.html>`_.
@@ -155,4 +155,3 @@ Questions? Suggestions?
 
 .. _JupyterHub: https://github.com/jupyterhub/jupyterhub
 .. _Jupyter notebook: https://jupyter-notebook.readthedocs.io/en/latest/
-.. _REST API: https://petstore3.swagger.io/?url=https://raw.githubusercontent.com/jupyterhub/jupyterhub/HEAD/docs/rest-api.yml#!/default

docs/source/quickstart.md

@@ -5,8 +5,8 @@
 Before installing JupyterHub, you will need:
 
 - a Linux/Unix based system
-- [Python](https://www.python.org/downloads/) 3.5 or greater. An understanding
+- [Python](https://www.python.org/downloads/) 3.6 or greater. An understanding
-  of using [`pip`](https://pip.pypa.io/en/stable/) or
+  of using [`pip`](https://pip.pypa.io) or
   [`conda`](https://conda.io/docs/get-started.html) for
   installing Python packages is helpful.
 - [nodejs/npm](https://www.npmjs.com/). [Install nodejs/npm](https://docs.npmjs.com/getting-started/installing-node),
@@ -20,11 +20,11 @@ Before installing JupyterHub, you will need:
     For example, install it on Linux (Debian/Ubuntu) using:
 
     ```
-    sudo apt-get install npm nodejs-legacy
+    sudo apt-get install nodejs npm
     ```
 
-    The `nodejs-legacy` package installs the `node` executable and is currently
+    [nodesource][] is a great resource to get more recent versions of the nodejs runtime,
-    required for npm to work on Debian/Ubuntu.
+    if your system package manager only has an old version of Node.js (e.g. 10 or older).
 
 - A [pluggable authentication module (PAM)](https://en.wikipedia.org/wiki/Pluggable_authentication_module)
   to use the [default Authenticator](./getting-started/authenticators-users-basics.md).
@@ -33,11 +33,17 @@ Before installing JupyterHub, you will need:
 - TLS certificate and key for HTTPS communication
 - Domain name
 
+[nodesource]: https://github.com/nodesource/distributions#table-of-contents
+
 Before running the single-user notebook servers (which may be on the same
 system as the Hub or not), you will need:
 
-- [Jupyter Notebook](https://jupyter.readthedocs.io/en/latest/install.html)
+- [JupyterLab][] version 3 or greater,
-  version 4 or greater
+  or [Jupyter Notebook][]
+  4 or greater.
+
+[jupyterlab]: https://jupyterlab.readthedocs.io
+[jupyter notebook]: https://jupyter.readthedocs.io/en/latest/install.html
 
 ## Installation
 
@@ -48,14 +54,14 @@ JupyterHub can be installed with `pip` (and the proxy with `npm`) or `conda`:
 ```bash
 python3 -m pip install jupyterhub
 npm install -g configurable-http-proxy
-python3 -m pip install notebook  # needed if running the notebook servers locally
+python3 -m pip install jupyterlab notebook  # needed if running the notebook servers in the same environment
 ```
 
 **conda** (one command installs jupyterhub and proxy):
 
 ```bash
 conda install -c conda-forge jupyterhub  # installs jupyterhub and proxy
-conda install notebook  # needed if running the notebook servers locally
+conda install jupyterlab notebook  # needed if running the notebook servers in the same environment
 ```
 
 Test your installation. If installed, these commands should return the packages'
@@ -74,7 +80,7 @@ To start the Hub server, run the command:
 jupyterhub
 ```
 
-Visit `https://localhost:8000` in your browser, and sign in with your unix
+Visit `http://localhost:8000` in your browser, and sign in with your unix
 credentials.
 
 To **allow multiple users to sign in** to the Hub server, you must start

docs/source/rbac/generate-scope-table.py

@@ -5,10 +5,12 @@ from pathlib import Path
 from pytablewriter import MarkdownTableWriter
 from ruamel.yaml import YAML
 
+import jupyterhub
 from jupyterhub.scopes import scope_definitions
 
 HERE = os.path.abspath(os.path.dirname(__file__))
-PARENT = Path(HERE).parent.parent.absolute()
+DOCS = Path(HERE).parent.parent.absolute()
+REST_API_YAML = DOCS.joinpath("source", "_static", "rest-api.yml")
 
 
 class ScopeTableGenerator:
@@ -98,13 +100,14 @@ class ScopeTableGenerator:
 
     def write_api(self):
         """Generates the API description in markdown format and writes it into `rest-api.yml`"""
-        filename = f"{PARENT}/rest-api.yml"
+        filename = REST_API_YAML
         yaml = YAML(typ='rt')
         yaml.preserve_quotes = True
         scope_dict = {}
-        with open(filename, 'r+') as f:
+        with open(filename) as f:
             content = yaml.load(f.read())
-            f.seek(0)
+
+        content["info"]["version"] = jupyterhub.__version__
         for scope in self.scopes:
             description = self.scopes[scope]['description']
             doc_description = self.scopes[scope].get('doc_description', '')
@@ -112,8 +115,9 @@ class ScopeTableGenerator:
                 description = doc_description
             scope_dict[scope] = description
         content['securityDefinitions']['oauth2']['scopes'] = scope_dict
+
+        with open(filename, 'w') as f:
             yaml.dump(content, f)
-            f.truncate()
 
 
 def main():

docs/source/rbac/roles.md

@@ -123,13 +123,13 @@ has,
 define the `server` role.
 
 To restore the JupyterHub 1.x behavior of servers being able to do anything their owners can do,
-use the scope `all`:
+use the scope `inherit` (for 'inheriting' the owner's permissions):
 
 ```python
 c.JupyterHub.load_roles = [
  {
    'name': 'server',
-   'scopes': ['all'],
+   'scopes': ['inherit'],
  }
 ]
 ```

docs/source/reference/config-proxy.md

@@ -219,7 +219,7 @@ In case of the need to run the jupyterhub under /jhub/ or other location please
 httpd.conf amendments:
 
 ```bash
- RewriteRule /jhub/(.*) ws://127.0.0.1:8000/jhub/$1 [NE.P,L]
+ RewriteRule /jhub/(.*) ws://127.0.0.1:8000/jhub/$1 [NE,P,L]
  RewriteRule /jhub/(.*) http://127.0.0.1:8000/jhub/$1 [NE,P,L]
 
  ProxyPass /jhub/ http://127.0.0.1:8000/jhub/

docs/source/reference/config-user-env.md

@@ -76,13 +76,26 @@ c.InteractiveShellApp.extensions.append("cython")
 
 ### Example: Enable a Jupyter notebook configuration setting for all users
 
+:::{note}
+These examples configure the Jupyter ServerApp,
+which is used by JupyterLab, the default in JupyterHub 2.0.
+
+If you are using the classing Jupyter Notebook server,
+the same things should work,
+with the following substitutions:
+
+- Where you see `jupyter_server_config`, use `jupyter_notebook_config`
+- Where you see `NotebookApp`, use `ServerApp`
+
+:::
+
 To enable Jupyter notebook's internal idle-shutdown behavior (requires
-notebook ≥ 5.4), set the following in the `/etc/jupyter/jupyter_notebook_config.py`
+notebook ≥ 5.4), set the following in the `/etc/jupyter/jupyter_server_config.py`
 file:
 
 ```python
 # shutdown the server after no activity for an hour
-c.NotebookApp.shutdown_no_activity_timeout = 60 * 60
+c.ServerApp.shutdown_no_activity_timeout = 60 * 60
 # shutdown kernels after no activity for 20 minutes
 c.MappingKernelManager.cull_idle_timeout = 20 * 60
 # check for idle kernels every two minutes
@@ -112,8 +125,8 @@ Assuming I have a Python 2 and Python 3 environment that I want to make
 sure are available, I can install their specs system-wide (in /usr/local) with:
 
 ```bash
-/path/to/python3 -m IPython kernel install --prefix=/usr/local
+/path/to/python3 -m ipykernel install --prefix=/usr/local
-/path/to/python2 -m IPython kernel install --prefix=/usr/local
+/path/to/python2 -m ipykernel install --prefix=/usr/local
 ```
 
 ## Multi-user hosts vs. Containers
@@ -176,12 +189,40 @@ The number of named servers per user can be limited by setting
 c.JupyterHub.named_server_limit_per_user = 5
 ```
 
-## Switching to Jupyter Server
+(classic-notebook-ui)=
 
-[Jupyter Server](https://jupyter-server.readthedocs.io/en/latest/) is a new Tornado Server backend for Jupyter web applications (e.g. JupyterLab 3.0 uses this package as its default backend).
+## Switching back to classic notebook
 
-By default, the single-user notebook server uses the (old) `NotebookApp` from the [notebook](https://github.com/jupyter/notebook) package. You can switch to using Jupyter Server's `ServerApp` backend (this will likely become the default in future releases) by setting the `JUPYTERHUB_SINGLEUSER_APP` environment variable to:
+By default the single-user server launches JupyterLab,
+which is based on [Jupyter Server][].
+This is the default server when running JupyterHub ≥ 2.0.
+You can switch to using the legacy Jupyter Notebook server by setting the `JUPYTERHUB_SINGLEUSER_APP` environment variable
+(in the single-user environment) to:
+
+```bash
+export JUPYTERHUB_SINGLEUSER_APP='notebook.notebookapp.NotebookApp'
+```
+
+[jupyter server]: https://jupyter-server.readthedocs.io
+[jupyter notebook]: https://jupyter-notebook.readthedocs.io
+
+:::{versionchanged} 2.0
+JupyterLab is now the default singleuser UI, if available,
+which is based on the [Jupyter Server][],
+no longer the legacy [Jupyter Notebook][] server.
+JupyterHub prior to 2.0 launched the legacy notebook server (`jupyter notebook`),
+and Jupyter server could be selected by specifying
+
+```python
+# jupyterhub_config.py
+c.Spawner.cmd = ["jupyter-labhub"]
+```
+
+or for an otherwise customized Jupyter Server app,
+set the environment variable:
 
 ```bash
 export JUPYTERHUB_SINGLEUSER_APP='jupyter_server.serverapp.ServerApp'
 ```
+
+:::

docs/source/reference/index.rst

@@ -16,6 +16,7 @@ what happens under-the-hood when you deploy and configure your JupyterHub.
    proxy
    separate-proxy
    rest
+   rest-api
    server-api
    monitoring
    database

docs/source/reference/rest-api.md

@@ -0,0 +1,27 @@
+# JupyterHub REST API
+
+Below is an interactive view of JupyterHub's OpenAPI specification.
+
+<!-- client-rendered openapi UI copied from FastAPI -->
+
+<link type="text/css" rel="stylesheet" href="https://cdn.jsdelivr.net/npm/swagger-ui-dist@3/swagger-ui.css">
+<script src="https://cdn.jsdelivr.net/npm/swagger-ui-dist@3/swagger-ui-bundle.js"></script>
+<!-- `SwaggerUIBundle` is now available on the page -->
+
+<!-- render the ui here -->
+<div id="openapi-ui"></div>
+
+<script>
+const ui = SwaggerUIBundle({
+  url: '../_static/rest-api.yml',
+  dom_id: '#openapi-ui',
+  presets: [
+    SwaggerUIBundle.presets.apis,
+    SwaggerUIBundle.SwaggerUIStandalonePreset
+  ],
+  layout: "BaseLayout",
+  deepLinking: true,
+  showExtensions: true,
+  showCommonExtensions: true,
+});
+</script>

docs/source/reference/rest-api.rst

@@ -1,14 +0,0 @@
-:orphan:
-
-===================
-JupyterHub REST API
-===================
-
-.. this doc exists as a resolvable link target
-.. which _static files are not
-
-.. meta::
-    :http-equiv=refresh: 0;url=../_static/rest-api/index.html
-
-The rest API docs are `here <../_static/rest-api/index.html>`_
-if you are not redirected automatically.

docs/source/reference/rest.md

@@ -302,12 +302,8 @@ or kubernetes pods.
 
 ## Learn more about the API
 
-You can see the full [JupyterHub REST API][] for details. This REST API Spec can
+You can see the full [JupyterHub REST API][] for details.
-be viewed in a more [interactive style on swagger's petstore][].
-Both resources contain the same information and differ only in its display.
-Note: The Swagger specification is being renamed the [OpenAPI Initiative][].
 
-[interactive style on swagger's petstore]: https://petstore3.swagger.io/?url=https://raw.githubusercontent.com/jupyterhub/jupyterhub/HEAD/docs/rest-api.yml#!/default
 [openapi initiative]: https://www.openapis.org/
 [jupyterhub rest api]: ./rest-api
 [jupyter notebook rest api]: https://petstore3.swagger.io/?url=https://raw.githubusercontent.com/jupyter/notebook/HEAD/notebook/services/api/api.yaml

docs/test_docs.py

@@ -0,0 +1,45 @@
+import sys
+from pathlib import Path
+from subprocess import run
+
+from ruamel.yaml import YAML
+
+yaml = YAML(typ="safe")
+
+here = Path(__file__).absolute().parent
+root = here.parent
+
+
+def test_rest_api_version():
+    version_py = root.joinpath("jupyterhub", "_version.py")
+    rest_api_yaml = root.joinpath("docs", "source", "_static", "rest-api.yml")
+    ns = {}
+    with version_py.open() as f:
+        exec(f.read(), {}, ns)
+    jupyterhub_version = ns["__version__"]
+
+    with rest_api_yaml.open() as f:
+        rest_api = yaml.load(f)
+        rest_api_version = rest_api["info"]["version"]
+
+    assert jupyterhub_version == rest_api_version
+
+
+def test_restapi_scopes():
+    run([sys.executable, "source/rbac/generate-scope-table.py"], cwd=here, check=True)
+    run(
+        ['pre-commit', 'run', 'prettier', '--files', 'source/_static/rest-api.yml'],
+        cwd=here,
+        check=False,
+    )
+    run(
+        [
+            "git",
+            "diff",
+            "--no-pager",
+            "--exit-code",
+            str(here.joinpath("source", "_static", "rest-api.yml")),
+        ],
+        cwd=here,
+        check=True,
+    )

examples/server-api/start-stop-server.py

@@ -29,7 +29,7 @@ def get_token():
     token_file = here.joinpath("service-token")
     log.info(f"Loading token from {token_file}")
     with token_file.open("r") as f:
-        token = f.read()
+        token = f.read().strip()
     return token
 
 

jsx/yarn.lock

@@ -5457,9 +5457,9 @@ npm-run-path@^4.0.0:
     path-key "^3.0.0"
 
 nth-check@^2.0.0:
-  version "2.0.0"
+  version "2.0.1"
-  resolved "https://registry.yarnpkg.com/nth-check/-/nth-check-2.0.0.tgz#1bb4f6dac70072fc313e8c9cd1417b5074c0a125"
+  resolved "https://registry.yarnpkg.com/nth-check/-/nth-check-2.0.1.tgz#2efe162f5c3da06a28959fbd3db75dbeea9f0fc2"
-  integrity sha512-i4sc/Kj8htBrAiH1viZ0TgU8Y5XqCaV/FziYK6TBczxmeKm3AEFWqqF3195yKudrarqy7Zu80Ra5dobFjn9X/Q==
+  integrity sha512-it1vE95zF6dTT9lBsYbxvqh0Soy4SPowchj0UBGj/V6cTPnXXtQOPUbhZ6CmGzAD/rW22LQK6E96pcdJXk4A4w==
   dependencies:
     boolbase "^1.0.0"
 
@@ -7278,9 +7278,9 @@ tiny-warning@^1.0.0, tiny-warning@^1.0.3:
   integrity sha512-lBN9zLN/oAf68o3zNXYrdCt1kP8WsiGW8Oo2ka41b2IM5JL/S1CTyX1rW0mb/zSuJun0ZUrDxx4sqvYS2FWzPA==
 
 tmpl@1.0.x:
-  version "1.0.4"
+  version "1.0.5"
-  resolved "https://registry.yarnpkg.com/tmpl/-/tmpl-1.0.4.tgz#23640dd7b42d00433911140820e5cf440e521dd1"
+  resolved "https://registry.yarnpkg.com/tmpl/-/tmpl-1.0.5.tgz#8683e0b902bb9c20c4f726e3c0b69f36518c07cc"
-  integrity sha1-I2QN17QtAEM5ERQIIOXPRA5SHdE=
+  integrity sha512-3f0uOEAQwIqGuWW2MVzYg8fV/QNnc/IpuJNG837rLuczAaLVHslWHZQj4IGiEl5Hs3kkbhwL9Ab7Hrsmuj+Smw==
 
 to-fast-properties@^2.0.0:
   version "2.0.0"

jupyterhub/_version.py

@@ -1,14 +1,8 @@
 """JupyterHub version info"""
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
-
+# version_info updated by running `tbump`
-version_info = (
+version_info = (2, 0, 0, "rc1", "")
-    2,
-    0,
-    0,
-    "b1",  # release (b1, rc1, or "" for final or dev)
-    # "dev",  # dev or nothing for beta/rc/stable releases
-)
 
 # pep 440 version: no dot before beta/rc, but before .dev
 # 0.1.0rc1
@@ -16,7 +10,9 @@ version_info = (
 # 0.1.0b1.dev
 # 0.1.0.dev
 
-__version__ = ".".join(map(str, version_info[:3])) + ".".join(version_info[3:])
+__version__ = ".".join(map(str, version_info[:3])) + ".".join(version_info[3:]).rstrip(
+    "."
+)
 
 # Singleton flag to only log the major/minor mismatch warning once per mismatch combo.
 _version_mismatch_warning_logged = {}

jupyterhub/apihandlers/auth.py

@@ -308,12 +308,14 @@ class OAuthAuthorizeHandler(OAuthHandler, BaseHandler):
                         "filter": "",
                     }
                 ]
-            elif 'all' in raw_scopes:
+            elif 'inherit' in raw_scopes:
-                raw_scopes = ['all']
+                raw_scopes = ['inherit']
                 scope_descriptions = [
                     {
-                        "scope": "all",
+                        "scope": "inherit",
-                        "description": scopes.scope_definitions['all']['description'],
+                        "description": scopes.scope_definitions['inherit'][
+                            'description'
+                        ],
                         "filter": "",
                     }
                 ]

jupyterhub/apihandlers/groups.py

@@ -129,7 +129,7 @@ class GroupAPIHandler(_GroupAPIHandler):
         self.write(json.dumps(self.group_model(group)))
         self.set_status(201)
 
-    @needs_scope('admin:groups')
+    @needs_scope('delete:groups')
     def delete(self, group_name):
         """Delete a group by name"""
         group = self.find_group(group_name)

jupyterhub/apihandlers/users.py

@@ -266,7 +266,7 @@ class UserAPIHandler(APIHandler):
         self.write(json.dumps(self.user_model(user)))
         self.set_status(201)
 
-    @needs_scope('admin:users')
+    @needs_scope('delete:users')
     async def delete(self, user_name):
         user = self.find_user(user_name)
         if user is None:
@@ -397,9 +397,11 @@ class UserTokenListAPIHandler(APIHandler):
         token_roles = body.get('roles')
         try:
             api_token = user.new_api_token(
-                note=note, expires_in=body.get('expires_in', None), roles=token_roles
+                note=note,
+                expires_in=body.get('expires_in', None),
+                roles=token_roles,
             )
-        except NameError:
+        except KeyError:
             raise web.HTTPError(404, "Requested roles %r not found" % token_roles)
         except ValueError:
             raise web.HTTPError(
@@ -421,6 +423,7 @@ class UserTokenListAPIHandler(APIHandler):
         token_model = self.token_model(orm.APIToken.find(self.db, api_token))
         token_model['token'] = api_token
         self.write(json.dumps(token_model))
+        self.set_status(201)
 
 
 class UserTokenAPIHandler(APIHandler):
@@ -483,6 +486,11 @@ class UserServerAPIHandler(APIHandler):
     @needs_scope('servers')
     async def post(self, user_name, server_name=''):
         user = self.find_user(user_name)
+        if user is None:
+            # this can be reached if a token has `servers`
+            # permission on *all* users
+            raise web.HTTPError(404)
+
         if server_name:
             if not self.allow_named_servers:
                 raise web.HTTPError(400, "Named servers are not enabled.")
@@ -525,7 +533,7 @@ class UserServerAPIHandler(APIHandler):
         self.set_header('Content-Type', 'text/plain')
         self.set_status(status)
 
-    @needs_scope('servers')
+    @needs_scope('delete:servers')
     async def delete(self, user_name, server_name=''):
         user = self.find_user(user_name)
         options = self.get_json_body()

jupyterhub/app.py

@@ -90,6 +90,7 @@ from .log import CoroutineLogFormatter, log_request
 from .proxy import Proxy, ConfigurableHTTPProxy
 from .traitlets import URLPrefix, Command, EntryPointType, Callable
 from .utils import (
+    AnyTimeoutError,
     catch_db_error,
     maybe_future,
     url_path_join,
@@ -1518,6 +1519,25 @@ class JupyterHub(Application):
         """,
     ).tag(config=True)
 
+    use_legacy_stopped_server_status_code = Bool(
+        False,
+        help="""
+        Return 503 rather than 424 when request comes in for a non-running server.
+
+        Prior to JupyterHub 2.0, we returned a 503 when any request came in for
+        a user server that was currently not running. By default, JupyterHub 2.0
+        will return a 424 - this makes operational metric dashboards more useful.
+
+        JupyterLab < 3.2 expected the 503 to know if the user server is no longer
+        running, and prompted the user to start their server. Set this config to
+        true to retain the old behavior, so JupyterLab < 3.2 can continue to show
+        the appropriate UI when the user server is stopped.
+
+        This option will be removed in a future release.
+        """,
+        config=True,
+    )
+
     def init_handlers(self):
         h = []
         # load handlers from the authenticator
@@ -2050,7 +2070,7 @@ class JupyterHub(Application):
                 if role_spec['name'] == 'admin':
                     app_log.warning(
                         "Configuration specifies both admin_users and users in the admin role specification. "
-                        "If admin role is present in config, c.authenticator.admin_users should not be used."
+                        "If admin role is present in config, c.Authenticator.admin_users should not be used."
                     )
                     app_log.info(
                         "Merging admin_users set with users list in admin role"
@@ -2089,7 +2109,7 @@ class JupyterHub(Application):
                                 )
                         Class = orm.get_class(kind)
                         orm_obj = Class.find(db, bname)
-                        if orm_obj:
+                        if orm_obj is not None:
                             orm_role_bearers.append(orm_obj)
                         else:
                             app_log.info(
@@ -2098,6 +2118,11 @@ class JupyterHub(Application):
                             if kind == 'users':
                                 orm_obj = await self._get_or_create_user(bname)
                                 orm_role_bearers.append(orm_obj)
+                            elif kind == 'groups':
+                                group = orm.Group(name=bname)
+                                db.add(group)
+                                db.commit()
+                                orm_role_bearers.append(group)
                             else:
                                 raise ValueError(
                                     f"{kind} {bname} defined in config role definition {predef_role['name']} but not present in database"
@@ -2331,7 +2356,7 @@ class JupyterHub(Application):
                 continue
             try:
                 await Server.from_orm(service.orm.server).wait_up(timeout=1, http=True)
-            except TimeoutError:
+            except AnyTimeoutError:
                 self.log.warning(
                     "Cannot connect to %s service %s at %s",
                     service.kind,
@@ -2409,7 +2434,7 @@ class JupyterHub(Application):
                 )
                 try:
                     await user._wait_up(spawner)
-                except TimeoutError:
+                except AnyTimeoutError:
                     self.log.error(
                         "%s does not appear to be running at %s, shutting it down.",
                         spawner._log_name,
@@ -2773,7 +2798,7 @@ class JupyterHub(Application):
             await gen.with_timeout(
                 timedelta(seconds=max(init_spawners_timeout, 1)), init_spawners_future
             )
-        except gen.TimeoutError:
+        except AnyTimeoutError:
             self.log.warning(
                 "init_spawners did not complete within %i seconds. "
                 "Allowing to complete in the background.",
@@ -3036,7 +3061,7 @@ class JupyterHub(Application):
                         await Server.from_orm(service.orm.server).wait_up(
                             http=True, timeout=1, ssl_context=ssl_context
                         )
-                    except TimeoutError:
+                    except AnyTimeoutError:
                         if service.managed:
                             status = await service.spawner.poll()
                             if status is not None:

jupyterhub/auth.py

@@ -1173,3 +1173,22 @@ class DummyAuthenticator(Authenticator):
                 return data['username']
             return None
         return data['username']
+
+
+class NullAuthenticator(Authenticator):
+    """Null Authenticator for JupyterHub
+
+    For cases where authentication should be disabled,
+    e.g. only allowing access via API tokens.
+
+    .. versionadded:: 2.0
+    """
+
+    # auto_login skips 'Login with...' page on Hub 0.8
+    auto_login = True
+
+    # for Hub 0.7, show 'login with...'
+    login_service = 'null'
+
+    def get_handlers(self, app):
+        return []

jupyterhub/handlers/base.py

@@ -47,6 +47,7 @@ from ..metrics import TOTAL_USERS
 from ..objects import Server
 from ..spawner import LocalProcessSpawner
 from ..user import User
+from ..utils import AnyTimeoutError
 from ..utils import get_accepted_mimetype
 from ..utils import maybe_future
 from ..utils import url_path_join
@@ -490,7 +491,7 @@ class BaseHandler(RequestHandler):
         session_id = self.get_session_cookie()
         if session_id:
             # clear session id
-            self.clear_cookie(SESSION_COOKIE_NAME, **kwargs)
+            self.clear_cookie(SESSION_COOKIE_NAME, path=self.base_url, **kwargs)
 
             if user:
                 # user is logged in, clear any tokens associated with the current session
@@ -569,7 +570,9 @@ class BaseHandler(RequestHandler):
         so other services on this domain can read it.
         """
         session_id = uuid.uuid4().hex
-        self._set_cookie(SESSION_COOKIE_NAME, session_id, encrypted=False)
+        self._set_cookie(
+            SESSION_COOKIE_NAME, session_id, encrypted=False, path=self.base_url
+        )
         return session_id
 
     def set_service_cookie(self, user):
@@ -1019,7 +1022,7 @@ class BaseHandler(RequestHandler):
             await gen.with_timeout(
                 timedelta(seconds=self.slow_spawn_timeout), finish_spawn_future
             )
-        except gen.TimeoutError:
+        except AnyTimeoutError:
             # waiting_for_response indicates server process has started,
             # but is yet to become responsive.
             if spawner._spawn_pending and not spawner._waiting_for_response:
@@ -1166,7 +1169,7 @@ class BaseHandler(RequestHandler):
 
         try:
             await gen.with_timeout(timedelta(seconds=self.slow_stop_timeout), future)
-        except gen.TimeoutError:
+        except AnyTimeoutError:
             # hit timeout, but stop is still pending
             self.log.warning(
                 "User %s:%s server is slow to stop (timeout=%s)",
@@ -1355,7 +1358,7 @@ class UserUrlHandler(BaseHandler):
 
     **Changed Behavior as of 1.0** This handler no longer triggers a spawn. Instead, it checks if:
 
-    1. server is not active, serve page prompting for spawn (status: 503)
+    1. server is not active, serve page prompting for spawn (status: 424)
     2. server is ready (This shouldn't happen! Proxy isn't updated yet. Wait a bit and redirect.)
     3. server is active, redirect to /hub/spawn-pending to monitor launch progress
        (will redirect back when finished)
@@ -1374,7 +1377,14 @@ class UserUrlHandler(BaseHandler):
         self.log.warning(
             "Failing suspected API request to not-running server: %s", self.request.path
         )
-        self.set_status(503)
+
+        # If we got here, the server is not running. To differentiate
+        # that the *server* itself is not running, rather than just the particular
+        # resource *in* the server is not found, we return a 424 instead of a 404.
+        # We allow retaining the old behavior to support older JupyterLab versions
+        self.set_status(
+            424 if not self.app.use_legacy_stopped_server_status_code else 503
+        )
         self.set_header("Content-Type", "application/json")
 
         spawn_url = urlparse(self.request.full_url())._replace(query="")
@@ -1539,15 +1549,17 @@ class UserUrlHandler(BaseHandler):
             self.redirect(pending_url, status=303)
             return
 
-        # if we got here, the server is not running
+        # If we got here, the server is not running. To differentiate
-        # serve a page prompting for spawn and 503 error
+        # that the *server* itself is not running, rather than just the particular
-        # visiting /user/:name no longer triggers implicit spawn
+        # page *in* the server is not found, we return a 424 instead of a 404.
-        # without explicit user action
+        # We allow retaining the old behavior to support older JupyterLab versions
         spawn_url = url_concat(
             url_path_join(self.hub.base_url, "spawn", user.escaped_name, server_name),
             {"next": self.request.uri},
         )
-        self.set_status(503)
+        self.set_status(
+            424 if not self.app.use_legacy_stopped_server_status_code else 503
+        )
 
         auth_state = await user.get_auth_state()
         html = await self.render_template(

jupyterhub/proxy.py

@@ -44,6 +44,7 @@ from . import utils
 from .metrics import CHECK_ROUTES_DURATION_SECONDS
 from .metrics import PROXY_POLL_DURATION_SECONDS
 from .objects import Server
+from .utils import AnyTimeoutError
 from .utils import exponential_backoff
 from .utils import url_path_join
 from jupyterhub.traitlets import Command
@@ -718,7 +719,7 @@ class ConfigurableHTTPProxy(Proxy):
                 _check_process()
                 try:
                     await server.wait_up(1)
-                except TimeoutError:
+                except AnyTimeoutError:
                     continue
                 else:
                     break

jupyterhub/roles.py

@@ -57,7 +57,7 @@ def get_default_roles():
         {
             'name': 'token',
             'description': 'Token with same permissions as its owner',
-            'scopes': ['all'],
+            'scopes': ['inherit'],
         },
     ]
     return default_roles
@@ -89,6 +89,7 @@ def expand_self_scope(name):
         'users:activity',
         'read:users:activity',
         'servers',
+        'delete:servers',
         'read:servers',
         'tokens',
         'read:tokens',
@@ -213,7 +214,7 @@ def _check_scopes(*args, rolename=None):
       or
       scopes (list): list of scopes to check
 
-    Raises NameError if scope does not exist
+    Raises KeyError if scope does not exist
     """
 
     allowed_scopes = set(scopes.scope_definitions.keys())
@@ -227,11 +228,13 @@ def _check_scopes(*args, rolename=None):
     for scope in args:
         scopename, _, filter_ = scope.partition('!')
         if scopename not in allowed_scopes:
-            raise NameError(f"Scope '{scope}' {log_role} does not exist")
+            if scopename == "all":
+                raise KeyError("Draft scope 'all' is now called 'inherit'")
+            raise KeyError(f"Scope '{scope}' {log_role} does not exist")
         if filter_:
             full_filter = f"!{filter_}"
             if not any(f in scope for f in allowed_filters):
-                raise NameError(
+                raise KeyError(
                     f"Scope filter '{full_filter}' in scope '{scope}' {log_role} does not exist"
                 )
 
@@ -321,7 +324,7 @@ def delete_role(db, rolename):
         db.commit()
         app_log.info('Role %s has been deleted', rolename)
     else:
-        raise NameError('Cannot remove role %r that does not exist', rolename)
+        raise KeyError('Cannot remove role %r that does not exist', rolename)
 
 
 def existing_only(func):
@@ -412,7 +415,7 @@ def _token_allowed_role(db, token, role):
 
     expanded_scopes = _get_subscopes(role, owner=owner)
 
-    implicit_permissions = {'all', 'read:all'}
+    implicit_permissions = {'inherit', 'read:inherit'}
     explicit_scopes = expanded_scopes - implicit_permissions
     # ignore horizontal filters
     no_filter_scopes = {
@@ -431,20 +434,20 @@ def _token_allowed_role(db, token, role):
         return True
     else:
         app_log.warning(
-            f"Token requesting scopes exceeding owner {owner.name}: {disallowed_scopes}"
+            f"Token requesting role {role.name} with scopes not held by owner {owner.name}: {disallowed_scopes}"
         )
         return False
 
 
 def assign_default_roles(db, entity):
-    """Assigns default role to an entity:
+    """Assigns default role(s) to an entity:
     users and services get 'user' role, or admin role if they have admin flag
     tokens get 'token' role
     """
     if isinstance(entity, orm.Group):
         pass
     elif isinstance(entity, orm.APIToken):
-        app_log.debug('Assigning default roles to tokens')
+        app_log.debug('Assigning default role to token')
         default_token_role = orm.Role.find(db, 'token')
         if not entity.roles and (entity.user or entity.service) is not None:
             default_token_role.tokens.append(entity)
@@ -453,15 +456,18 @@ def assign_default_roles(db, entity):
     # users and services can have 'user' or 'admin' roles as default
     else:
         kind = type(entity).__name__
-        app_log.debug(f'Assigning default roles to {kind} {entity.name}')
+        app_log.debug(f'Assigning default role to {kind} {entity.name}')
         _switch_default_role(db, entity, entity.admin)
 
 
 def update_roles(db, entity, roles):
-    """Updates object's roles checking for requested permissions
+    """Add roles to an entity (token, user, etc.)
-    if object is orm.APIToken
+
+    If it is an API token, check role permissions against token owner
+    prior to assignment to avoid permission expansion.
+
+    Otherwise, it just calls `grant_role` for each role.
     """
-    standard_permissions = {'all', 'read:all'}
     for rolename in roles:
         if isinstance(entity, orm.APIToken):
             role = orm.Role.find(db, rolename)
@@ -474,12 +480,11 @@ def update_roles(db, entity, roles):
                     app_log.info('Adding role %s to token: %s', role.name, entity)
                 else:
                     raise ValueError(
-                        f'Requested token role {rolename} of {entity} has more permissions than the token owner'
+                        f'Requested token role {rolename} for {entity} has more permissions than the token owner'
                     )
             else:
-                raise NameError('Role %r does not exist' % rolename)
+                raise KeyError(f'Role {rolename} does not exist')
         else:
-            app_log.debug('Assigning default roles to %s', type(entity).__name__)
             grant_role(db, entity=entity, rolename=rolename)
 
 

jupyterhub/scopes.py

@@ -30,19 +30,22 @@ scope_definitions = {
         'description': 'Your own resources',
         'doc_description': 'The user’s own resources _(metascope for users, resolves to (no_scope) for services)_',
     },
-    'all': {
+    'inherit': {
         'description': 'Anything you have access to',
         'doc_description': 'Everything that the token-owning entity can access _(metascope for tokens)_',
     },
     'admin:users': {
         'description': 'Read, write, create and delete users and their authentication state, not including their servers or tokens.',
-        'subscopes': ['admin:auth_state', 'users', 'read:roles:users'],
+        'subscopes': ['admin:auth_state', 'users', 'read:roles:users', 'delete:users'],
     },
     'admin:auth_state': {'description': 'Read a user’s authentication state.'},
     'users': {
         'description': 'Read and write permissions to user models (excluding servers, tokens and authentication state).',
         'subscopes': ['read:users', 'list:users', 'users:activity'],
     },
+    'delete:users': {
+        'description': "Delete users.",
+    },
     'list:users': {
         'description': 'List users, including at least their names.',
         'subscopes': ['read:users:name'],
@@ -76,12 +79,13 @@ scope_definitions = {
     'admin:server_state': {'description': 'Read and write users’ server state.'},
     'servers': {
         'description': 'Start and stop user servers.',
-        'subscopes': ['read:servers'],
+        'subscopes': ['read:servers', 'delete:servers'],
     },
     'read:servers': {
         'description': 'Read users’ names and their server models (excluding the server state).',
         'subscopes': ['read:users:name'],
     },
+    'delete:servers': {'description': "Stop and delete users' servers."},
     'tokens': {
         'description': 'Read, write, create and delete user tokens.',
         'subscopes': ['read:tokens'],
@@ -89,7 +93,7 @@ scope_definitions = {
     'read:tokens': {'description': 'Read user tokens.'},
     'admin:groups': {
         'description': 'Read and write group information, create and delete groups.',
-        'subscopes': ['groups', 'read:roles:groups'],
+        'subscopes': ['groups', 'read:roles:groups', 'delete:groups'],
     },
     'groups': {
         'description': 'Read and write group information, including adding/removing users to/from groups.',
@@ -104,6 +108,9 @@ scope_definitions = {
         'subscopes': ['read:groups:name'],
     },
     'read:groups:name': {'description': 'Read group names.'},
+    'delete:groups': {
+        'description': "Delete groups.",
+    },
     'list:services': {
         'description': 'List services, including at least their names.',
         'subscopes': ['read:services:name'],
@@ -310,13 +317,13 @@ def get_scopes_for(orm_object):
 
         owner_scopes = roles.expand_roles_to_scopes(owner)
 
-        if token_scopes == {'all'}:
+        if token_scopes == {'inherit'}:
-            # token_scopes is only 'all', return owner scopes as-is
+            # token_scopes is only 'inherit', return scopes inherited from owner as-is
             # short-circuit common case where we don't need to compute an intersection
             return owner_scopes
 
-        if 'all' in token_scopes:
+        if 'inherit' in token_scopes:
-            token_scopes.remove('all')
+            token_scopes.remove('inherit')
             token_scopes |= owner_scopes
 
         intersection = _intersect_expanded_scopes(

jupyterhub/singleuser/app.py

@@ -1,7 +1,12 @@
 """Make a single-user app based on the environment:
 
 - $JUPYTERHUB_SINGLEUSER_APP, the base Application class, to be wrapped in JupyterHub authentication.
-  default: notebook.notebookapp.NotebookApp
+  default: jupyter_server.serverapp.ServerApp
+
+.. versionchanged:: 2.0
+
+    Default app changed to launch `jupyter labhub`.
+    Use JUPYTERHUB_SINGLEUSER_APP=notebook.notebookapp.NotebookApp for the legacy 'classic' notebook server.
 """
 import os
 
@@ -9,12 +14,55 @@ from traitlets import import_item
 
 from .mixins import make_singleuser_app
 
-JUPYTERHUB_SINGLEUSER_APP = (
+JUPYTERHUB_SINGLEUSER_APP = os.environ.get("JUPYTERHUB_SINGLEUSER_APP")
-    os.environ.get("JUPYTERHUB_SINGLEUSER_APP") or "notebook.notebookapp.NotebookApp"
-)
 
+
+if JUPYTERHUB_SINGLEUSER_APP:
     App = import_item(JUPYTERHUB_SINGLEUSER_APP)
+else:
+    App = None
+    _import_error = None
+    for JUPYTERHUB_SINGLEUSER_APP in (
+        "jupyter_server.serverapp.ServerApp",
+        "notebook.notebookapp.NotebookApp",
+    ):
+        try:
+            App = import_item(JUPYTERHUB_SINGLEUSER_APP)
+        except ImportError as e:
+            continue
+            if _import_error is None:
+                _import_error = e
+        else:
+            break
+    if App is None:
+        raise _import_error
+
 
 SingleUserNotebookApp = make_singleuser_app(App)
 
-main = SingleUserNotebookApp.launch_instance
+
+def main():
+    """Launch a jupyterhub single-user server"""
+    if not os.environ.get("JUPYTERHUB_SINGLEUSER_APP"):
+        # app not specified, launch jupyter-labhub by default,
+        # if jupyterlab is recent enough (3.1).
+        # This is a minimally extended ServerApp that does:
+        # 1. ensure lab extension is enabled, and
+        # 2. set default URL to `/lab`
+        import re
+
+        _version_pat = re.compile(r"(\d+)\.(\d+)")
+        try:
+            import jupyterlab
+            from jupyterlab.labhubapp import SingleUserLabApp
+
+            m = _version_pat.match(jupyterlab.__version__)
+        except Exception:
+            m = None
+
+        if m is not None:
+            version_tuple = tuple(int(v) for v in m.groups())
+            if version_tuple >= (3, 1):
+                return SingleUserLabApp.launch_instance()
+
+    return SingleUserNotebookApp.launch_instance()

jupyterhub/spawner.py

@@ -15,8 +15,6 @@ from subprocess import Popen
 from tempfile import mkdtemp
 from urllib.parse import urlparse
 
-if os.name == 'nt':
-    import psutil
 from async_generator import aclosing
 from sqlalchemy import inspect
 from tornado.ioloop import PeriodicCallback
@@ -38,12 +36,14 @@ from .objects import Server
 from .traitlets import ByteSpecification
 from .traitlets import Callable
 from .traitlets import Command
+from .utils import AnyTimeoutError
 from .utils import exponential_backoff
 from .utils import maybe_future
 from .utils import random_port
 from .utils import url_path_join
 
-# FIXME: remove when we drop Python 3.5 support
+if os.name == 'nt':
+    import psutil
 
 
 def _quote_safe(s):
@@ -1263,7 +1263,7 @@ class Spawner(LoggingConfigurable):
                 timeout=timeout,
             )
             return r
-        except TimeoutError:
+        except AnyTimeoutError:
             return False
 
 

jupyterhub/tests/test_api.py

@@ -972,6 +972,11 @@ async def test_bad_spawn(app, bad_spawn):
     assert app.users.count_active_users()['pending'] == 0
 
 
+async def test_spawn_nosuch_user(app):
+    r = await api_request(app, 'users', "nosuchuser", 'server', method='post')
+    assert r.status_code == 404
+
+
 async def test_slow_bad_spawn(app, no_patience, slow_bad_spawn):
     db = app.db
     name = 'zaphod'
@@ -1366,8 +1371,8 @@ async def test_get_new_token_deprecated(app, headers, status):
 @mark.parametrize(
     "headers, status, note, expires_in",
     [
-        ({}, 200, 'test note', None),
+        ({}, 201, 'test note', None),
-        ({}, 200, '', 100),
+        ({}, 201, '', 100),
         ({'Authorization': 'token bad'}, 403, '', None),
     ],
 )
@@ -1386,7 +1391,7 @@ async def test_get_new_token(app, headers, status, note, expires_in):
         app, 'users/admin/tokens', method='post', headers=headers, data=body
     )
     assert r.status_code == status
-    if status != 200:
+    if status != 201:
         return
     # check the new-token reply
     reply = r.json()
@@ -1424,10 +1429,10 @@ async def test_get_new_token(app, headers, status, note, expires_in):
 @mark.parametrize(
     "as_user, for_user, status",
     [
-        ('admin', 'other', 200),
+        ('admin', 'other', 201),
         ('admin', 'missing', 403),
         ('user', 'other', 403),
-        ('user', 'user', 200),
+        ('user', 'user', 201),
     ],
 )
 async def test_token_for_user(app, as_user, for_user, status):
@@ -1448,7 +1453,7 @@ async def test_token_for_user(app, as_user, for_user, status):
     )
     assert r.status_code == status
     reply = r.json()
-    if status != 200:
+    if status != 201:
         return
     assert 'token' in reply
 
@@ -1486,7 +1491,7 @@ async def test_token_authenticator_noauth(app):
         data=json.dumps(data) if data else None,
         noauth=True,
     )
-    assert r.status_code == 200
+    assert r.status_code == 201
     reply = r.json()
     assert 'token' in reply
     r = await api_request(app, 'authorizations', 'token', reply['token'])
@@ -1509,7 +1514,7 @@ async def test_token_authenticator_dict_noauth(app):
         data=json.dumps(data) if data else None,
         noauth=True,
     )
-    assert r.status_code == 200
+    assert r.status_code == 201
     reply = r.json()
     assert 'token' in reply
     r = await api_request(app, 'authorizations', 'token', reply['token'])

jupyterhub/tests/test_auth.py

@@ -3,6 +3,7 @@
 # Distributed under the terms of the Modified BSD License.
 import logging
 from unittest import mock
+from urllib.parse import urlparse
 
 import pytest
 from requests import HTTPError
@@ -12,6 +13,8 @@ from .mocking import MockPAMAuthenticator
 from .mocking import MockStructGroup
 from .mocking import MockStructPasswd
 from .utils import add_user
+from .utils import async_requests
+from .utils import public_url
 from jupyterhub import auth
 from jupyterhub import crypto
 from jupyterhub import orm
@@ -515,3 +518,12 @@ def test_deprecated_methods_subclass():
     assert authenticator.check_whitelist("subclass-allowed")
     assert not authenticator.check_allowed("otheruser")
     assert not authenticator.check_whitelist("otheruser")
+
+
+async def test_nullauthenticator(app):
+    with mock.patch.dict(
+        app.tornado_settings, {"authenticator": auth.NullAuthenticator(parent=app)}
+    ):
+        r = await async_requests.get(public_url(app))
+    assert urlparse(r.url).path.endswith("/hub/login")
+    assert r.status_code == 403

jupyterhub/tests/test_internal_ssl_connections.py

@@ -1,16 +1,13 @@
 """Tests for jupyterhub internal_ssl connections"""
 import sys
 import time
-from subprocess import check_output
 from unittest import mock
-from urllib.parse import urlparse
 
 import pytest
 from requests.exceptions import ConnectionError
 from requests.exceptions import SSLError
-from tornado import gen
 
-import jupyterhub
+from ..utils import AnyTimeoutError
 from .test_api import add_user
 from .utils import async_requests
 
@@ -35,7 +32,7 @@ async def wait_for_spawner(spawner, timeout=10):
         assert status is None
         try:
             await wait()
-        except TimeoutError:
+        except AnyTimeoutError:
             continue
         else:
             break

jupyterhub/tests/test_pages.py

@@ -56,8 +56,8 @@ async def test_root_redirect(app):
     r = await get_page(url, app, cookies=cookies)
     path = urlparse(r.url).path
     assert path == ujoin(app.base_url, 'hub/user/%s/test.ipynb' % name)
-    # serve "server not running" page, which has status 503
+    # serve "server not running" page, which has status 424
-    assert r.status_code == 503
+    assert r.status_code == 424
 
 
 async def test_root_default_url_noauth(app):
@@ -172,7 +172,7 @@ async def test_spawn_redirect(app):
     r = await get_page('user/' + name, app, hub=False, cookies=cookies)
     path = urlparse(r.url).path
     assert path == ujoin(app.base_url, 'hub/user/%s/' % name)
-    assert r.status_code == 503
+    assert r.status_code == 424
 
 
 async def test_spawn_handler_access(app):
@@ -507,13 +507,13 @@ async def test_user_redirect_deprecated(app, username):
     print(urlparse(r.url))
     path = urlparse(r.url).path
     assert path == ujoin(app.base_url, 'hub/user/%s/' % name)
-    assert r.status_code == 503
+    assert r.status_code == 424
 
     r = await get_page('/user/baduser/test.ipynb', app, cookies=cookies, hub=False)
     print(urlparse(r.url))
     path = urlparse(r.url).path
     assert path == ujoin(app.base_url, 'hub/user/%s/test.ipynb' % name)
-    assert r.status_code == 503
+    assert r.status_code == 424
 
     r = await get_page('/user/baduser/test.ipynb', app, hub=False)
     r.raise_for_status()
@@ -1061,13 +1061,20 @@ async def test_token_page(app):
 async def test_server_not_running_api_request(app):
     cookies = await app.login_user("bees")
     r = await get_page("user/bees/api/status", app, hub=False, cookies=cookies)
-    assert r.status_code == 503
+    assert r.status_code == 424
     assert r.headers["content-type"] == "application/json"
     message = r.json()['message']
     assert ujoin(app.base_url, "hub/spawn/bees") in message
     assert " /user/bees" in message
 
 
+async def test_server_not_running_api_request_legacy_status(app):
+    app.use_legacy_stopped_server_status_code = True
+    cookies = await app.login_user("bees")
+    r = await get_page("user/bees/api/status", app, hub=False, cookies=cookies)
+    assert r.status_code == 503
+
+
 async def test_metrics_no_auth(app):
     r = await get_page("metrics", app)
     assert r.status_code == 403

jupyterhub/tests/test_roles.py

@@ -28,7 +28,7 @@ def test_orm_roles(db):
         user_role = orm.Role(name='user', scopes=['self'])
         db.add(user_role)
     if not token_role:
-        token_role = orm.Role(name='token', scopes=['all'])
+        token_role = orm.Role(name='token', scopes=['inherit'])
         db.add(token_role)
     if not service_role:
         service_role = orm.Role(name='service', scopes=[])
@@ -182,6 +182,7 @@ def test_orm_roles_delete_cascade(db):
                 'admin:users',
                 'admin:auth_state',
                 'users',
+                'delete:users',
                 'list:users',
                 'read:users',
                 'users:activity',
@@ -218,6 +219,7 @@ def test_orm_roles_delete_cascade(db):
             {
                 'admin:groups',
                 'groups',
+                'delete:groups',
                 'list:groups',
                 'read:groups',
                 'read:roles:groups',
@@ -229,6 +231,7 @@ def test_orm_roles_delete_cascade(db):
             {
                 'admin:groups',
                 'groups',
+                'delete:groups',
                 'list:groups',
                 'read:groups',
                 'read:roles:groups',
@@ -366,7 +369,7 @@ async def test_creating_roles(app, role, role_def, response_type, response):
             'info',
             app_log.info('Role user scopes attribute has been changed'),
         ),
-        ('non-existing', 'test-role2', 'error', NameError),
+        ('non-existing', 'test-role2', 'error', KeyError),
         ('default', 'user', 'error', ValueError),
     ],
 )
@@ -407,9 +410,9 @@ async def test_delete_roles(db, role_type, rolename, response_type, response):
             },
             'existing',
         ),
-        ({'name': 'test-scopes-2', 'scopes': ['uses']}, NameError),
+        ({'name': 'test-scopes-2', 'scopes': ['uses']}, KeyError),
-        ({'name': 'test-scopes-3', 'scopes': ['users:activities']}, NameError),
+        ({'name': 'test-scopes-3', 'scopes': ['users:activities']}, KeyError),
-        ({'name': 'test-scopes-4', 'scopes': ['groups!goup=class-A']}, NameError),
+        ({'name': 'test-scopes-4', 'scopes': ['groups!goup=class-A']}, KeyError),
     ],
 )
 async def test_scope_existence(tmpdir, request, role, response):
@@ -428,7 +431,7 @@ async def test_scope_existence(tmpdir, request, role, response):
         assert added_role is not None
         assert added_role.scopes == role['scopes']
 
-    elif response == NameError:
+    elif response == KeyError:
         with pytest.raises(response):
             roles.create_role(db, role)
         added_role = orm.Role.find(db, role['name'])
@@ -575,7 +578,7 @@ async def test_load_roles_groups(tmpdir, request):
             'name': 'head',
             'description': 'Whole user access',
             'scopes': ['users', 'admin:users'],
-            'groups': ['group3'],
+            'groups': ['group3', "group4"],
         },
     ]
     kwargs = {'load_groups': groups_to_load, 'load_roles': roles_to_load}
@@ -595,11 +598,13 @@ async def test_load_roles_groups(tmpdir, request):
     group1 = orm.Group.find(db, name='group1')
     group2 = orm.Group.find(db, name='group2')
     group3 = orm.Group.find(db, name='group3')
+    group4 = orm.Group.find(db, name='group4')
 
     # test group roles
     assert group1.roles == []
     assert group2 in assist_role.groups
     assert group3 in head_role.groups
+    assert group4 in head_role.groups
 
     # delete the test roles
     for role in roles_to_load:
@@ -658,11 +663,11 @@ async def test_load_roles_user_tokens(tmpdir, request):
     "headers, rolename, scopes, status",
     [
         # no role requested - gets default 'token' role
-        ({}, None, None, 200),
+        ({}, None, None, 201),
         # role scopes within the user's default 'user' role
-        ({}, 'self-reader', ['read:users'], 200),
+        ({}, 'self-reader', ['read:users'], 201),
         # role scopes outside of the user's role but within the group's role scopes of which the user is a member
-        ({}, 'groups-reader', ['read:groups'], 200),
+        ({}, 'groups-reader', ['read:groups'], 201),
         # non-existing role request
         ({}, 'non-existing', [], 404),
         # role scopes outside of both user's role and group's role scopes

jupyterhub/tests/test_scopes.py

@@ -477,7 +477,7 @@ async def test_metascope_all_expansion(app, create_user_with_scopes):
     user = create_user_with_scopes('self')
     user.new_api_token()
     token = user.api_tokens[0]
-    # Check 'all' expansion
+    # Check 'inherit' expansion
     token_scope_set = get_scopes_for(token)
     user_scope_set = get_scopes_for(user)
     assert user_scope_set == token_scope_set

jupyterhub/tests/test_singleuser.py

@@ -1,6 +1,10 @@
 """Tests for jupyterhub.singleuser"""
+import os
 import sys
+from contextlib import contextmanager
+from subprocess import CalledProcessError
 from subprocess import check_output
+from unittest import mock
 from urllib.parse import urlparse
 
 import pytest
@@ -14,6 +18,12 @@ from .utils import async_requests
 from .utils import AsyncSession
 
 
+@contextmanager
+def nullcontext():
+    """Python 3.7+ contextlib.nullcontext, backport for 3.6"""
+    yield
+
+
 @pytest.mark.parametrize(
     "access_scopes, server_name, expect_success",
     [
@@ -171,3 +181,47 @@ def test_version():
         [sys.executable, '-m', 'jupyterhub.singleuser', '--version']
     ).decode('utf8', 'replace')
     assert jupyterhub.__version__ in out
+
+
+@pytest.mark.parametrize(
+    "JUPYTERHUB_SINGLEUSER_APP",
+    [
+        "",
+        "notebook.notebookapp.NotebookApp",
+        "jupyter_server.serverapp.ServerApp",
+    ],
+)
+def test_singleuser_app_class(JUPYTERHUB_SINGLEUSER_APP):
+    try:
+        import jupyter_server  # noqa
+    except ImportError:
+        have_server = False
+        expect_error = "jupyter_server" in JUPYTERHUB_SINGLEUSER_APP
+    else:
+        have_server = True
+        expect_error = False
+
+    if expect_error:
+        ctx = pytest.raises(CalledProcessError)
+    else:
+        ctx = nullcontext()
+
+    with mock.patch.dict(
+        os.environ,
+        {
+            "JUPYTERHUB_SINGLEUSER_APP": JUPYTERHUB_SINGLEUSER_APP,
+        },
+    ):
+        with ctx:
+            out = check_output(
+                [sys.executable, '-m', 'jupyterhub.singleuser', '--help-all']
+            ).decode('utf8', 'replace')
+    if expect_error:
+        return
+    # use help-all output to check inheritance
+    if 'NotebookApp' in JUPYTERHUB_SINGLEUSER_APP or not have_server:
+        assert '--NotebookApp.' in out
+        assert '--ServerApp.' not in out
+    else:
+        assert '--ServerApp.' in out
+        assert '--NotebookApp.' not in out

jupyterhub/tests/test_spawner.py

@@ -21,6 +21,7 @@ from ..objects import Server
 from ..spawner import LocalProcessSpawner
 from ..spawner import Spawner
 from ..user import User
+from ..utils import AnyTimeoutError
 from ..utils import new_token
 from ..utils import url_path_join
 from .mocking import public_url
@@ -95,7 +96,7 @@ async def wait_for_spawner(spawner, timeout=10):
         assert status is None
         try:
             await wait()
-        except TimeoutError:
+        except AnyTimeoutError:
             continue
         else:
             break

jupyterhub/user.py

@@ -26,11 +26,41 @@ from .metrics import RUNNING_SERVERS
 from .metrics import TOTAL_USERS
 from .objects import Server
 from .spawner import LocalProcessSpawner
+from .utils import AnyTimeoutError
 from .utils import make_ssl_context
 from .utils import maybe_future
 from .utils import url_path_join
 
 
+# detailed messages about the most common failure-to-start errors,
+# which manifest timeouts during start
+start_timeout_message = """
+Common causes of this timeout, and debugging tips:
+
+1. Everything is working, but it took too long.
+   To fix: increase `Spawner.start_timeout` configuration
+   to a number of seconds that is enough for spawners to finish starting.
+2. The server didn't finish starting,
+   or it crashed due to a configuration issue.
+   Check the single-user server's logs for hints at what needs fixing.
+"""
+
+http_timeout_message = """
+Common causes of this timeout, and debugging tips:
+
+1. The server didn't finish starting,
+   or it crashed due to a configuration issue.
+   Check the single-user server's logs for hints at what needs fixing.
+2. The server started, but is not accessible at the specified URL.
+   This may be a configuration issue specific to your chosen Spawner.
+   Check the single-user server logs and resource to make sure the URL
+   is correct and accessible from the Hub.
+3. (unlikely) Everything is working, but the server took too long to respond.
+   To fix: increase `Spawner.http_timeout` configuration
+   to a number of seconds that is enough for servers to become responsive.
+"""
+
+
 class UserDict(dict):
     """Like defaultdict, but for users
 
@@ -84,7 +114,7 @@ class UserDict(dict):
                 if user.name == key:
                     key = user.id
                     break
-        return dict.__contains__(self, key)
+        return super().__contains__(key)
 
     def __getitem__(self, key):
         """UserDict allows retrieval of user by any of:
@@ -108,7 +138,7 @@ class UserDict(dict):
             if orm_user.id not in self:
                 user = self[orm_user.id] = User(orm_user, self.settings)
                 return user
-            user = dict.__getitem__(self, orm_user.id)
+            user = super().__getitem__(orm_user.id)
             user.db = self.db
             return user
         elif isinstance(key, int):
@@ -119,7 +149,7 @@ class UserDict(dict):
                     raise KeyError("No such user: %s" % id)
                 user = self.add(orm_user)
             else:
-                user = dict.__getitem__(self, id)
+                user = super().__getitem__(id)
             return user
         else:
             raise KeyError(repr(key))
@@ -145,7 +175,7 @@ class UserDict(dict):
                 self.db.expunge(orm_spawner)
         if user.orm_user in self.db:
             self.db.expunge(user.orm_user)
-        dict.__delitem__(self, user.id)
+        super().__delitem__(user.id)
 
     def delete(self, key):
         """Delete a user from the cache and the database"""
@@ -707,11 +737,11 @@ class User:
                     db.commit()
 
         except Exception as e:
-            if isinstance(e, gen.TimeoutError):
+            if isinstance(e, AnyTimeoutError):
                 self.log.warning(
-                    "{user}'s server failed to start in {s} seconds, giving up".format(
+                    f"{self.name}'s server failed to start"
-                        user=self.name, s=spawner.start_timeout
+                    f" in {spawner.start_timeout} seconds, giving up."
-                    )
+                    f"\n{start_timeout_message}"
                 )
                 e.reason = 'timeout'
                 self.settings['statsd'].incr('spawner.failure.timeout')
@@ -764,14 +794,11 @@ class User:
                 http=True, timeout=spawner.http_timeout, ssl_context=ssl_context
             )
         except Exception as e:
-            if isinstance(e, TimeoutError):
+            if isinstance(e, AnyTimeoutError):
                 self.log.warning(
-                    "{user}'s server never showed up at {url} "
+                    f"{self.name}'s server never showed up at {server.url}"
-                    "after {http_timeout} seconds. Giving up".format(
+                    f" after {spawner.http_timeout} seconds. Giving up."
-                        user=self.name,
+                    f"\n{http_timeout_message}"
-                        url=server.url,
-                        http_timeout=spawner.http_timeout,
-                    )
                 )
                 e.reason = 'timeout'
                 self.settings['statsd'].incr('spawner.failure.http_timeout')

jupyterhub/utils.py

@@ -23,12 +23,12 @@ from operator import itemgetter
 
 from async_generator import aclosing
 from sqlalchemy.exc import SQLAlchemyError
+from tornado import gen
 from tornado import ioloop
 from tornado import web
 from tornado.httpclient import AsyncHTTPClient
 from tornado.httpclient import HTTPError
 from tornado.log import app_log
-from tornado.platform.asyncio import to_asyncio_future
 
 # For compatibility with python versions 3.6 or earlier.
 # asyncio.Task.all_tasks() is fully moved to asyncio.all_tasks() starting with 3.9. Also applies to current_task.
@@ -97,6 +97,10 @@ def make_ssl_context(keyfile, certfile, cafile=None, verify=True, check_hostname
     return ssl_context
 
 
+# AnyTimeoutError catches TimeoutErrors coming from asyncio, tornado, stdlib
+AnyTimeoutError = (gen.TimeoutError, asyncio.TimeoutError, TimeoutError)
+
+
 async def exponential_backoff(
     pass_func,
     fail_message,
@@ -182,7 +186,7 @@ async def exponential_backoff(
         if dt < max_wait:
             scale *= scale_factor
         await asyncio.sleep(dt)
-    raise TimeoutError(fail_message)
+    raise asyncio.TimeoutError(fail_message)
 
 
 async def wait_for_server(ip, port, timeout=10):
@@ -288,6 +292,31 @@ def authenticated_403(self):
         raise web.HTTPError(403)
 
 
+def admin_only(f):
+    """Deprecated!"""
+    # write it this way to trigger deprecation warning at decoration time,
+    # not on the method call
+    warnings.warn(
+        """@jupyterhub.utils.admin_only is deprecated in JupyterHub 2.0.
+
+        Use the new `@jupyterhub.scopes.needs_scope` decorator to resolve permissions,
+        or check against `self.current_user.parsed_scopes`.
+        """,
+        DeprecationWarning,
+        stacklevel=2,
+    )
+
+    # the original decorator
+    @auth_decorator
+    def admin_only(self):
+        """Decorator for restricting access to admin users"""
+        user = self.current_user
+        if user is None or not user.admin:
+            raise web.HTTPError(403)
+
+    return admin_only(f)
+
+
 @auth_decorator
 def metrics_authentication(self):
     """Decorator for restricting access to metrics"""

pyproject.toml

@@ -5,3 +5,41 @@ target_version = [
     "py37",
     "py38",
 ]
+
+[tool.tbump]
+# Uncomment this if your project is hosted on GitHub:
+github_url = "https://github.com/jupyterhub/jupyterhub"
+
+[tool.tbump.version]
+current = "2.0.0rc1"
+
+# Example of a semver regexp.
+# Make sure this matches current_version before
+# using tbump
+regex = '''
+  (?P<major>\d+)
+  \.
+  (?P<minor>\d+)
+  \.
+  (?P<patch>\d+)
+  (?P<pre>((a|b|rc)\d+)|)
+  \.?
+  (?P<dev>(?<=\.)dev\d*|)
+  '''
+
+[tool.tbump.git]
+message_template = "Bump to {new_version}"
+tag_template = "{new_version}"
+
+# For each file to patch, add a [[tool.tbump.file]] config
+# section containing the path of the file, relative to the
+# pyproject.toml location.
+
+[[tool.tbump.file]]
+src = "jupyterhub/_version.py"
+version_template = '({major}, {minor}, {patch}, "{pre}", "{dev}")'
+search = "version_info = {current_version}"
+
+[[tool.tbump.file]]
+src = "docs/source/_static/rest-api.yml"
+search = "version: {current_version}"

setup.py

@@ -100,6 +100,7 @@ setup_args = dict(
             'default = jupyterhub.auth:PAMAuthenticator',
             'pam = jupyterhub.auth:PAMAuthenticator',
             'dummy = jupyterhub.auth:DummyAuthenticator',
+            'null = jupyterhub.auth:NullAuthenticator',
         ],
         'jupyterhub.proxies': [
             'default = jupyterhub.proxy:ConfigurableHTTPProxy',
@@ -301,7 +302,7 @@ class develop_js_css(develop):
         if not self.uninstall:
             self.distribution.run_command('js')
             self.distribution.run_command('css')
-        develop.run(self)
+        super().run()
 
 
 setup_args['cmdclass']['develop'] = develop_js_css

singleuser/Dockerfile

@@ -7,6 +7,6 @@ MAINTAINER Project Jupyter <jupyter@googlegroups.com>
 
 ADD install_jupyterhub /tmp/install_jupyterhub
 ARG JUPYTERHUB_VERSION=main
-# install pinned jupyterhub and ensure notebook is installed
+# install pinned jupyterhub and ensure jupyterlab is installed
 RUN python3 /tmp/install_jupyterhub && \
-    python3 -m pip install notebook
+    python3 -m pip install jupyterlab