jupyterhub-1219 Enhancement: automatically create a directory for the user after successful login

examples/bootstrap-script/README.md

@@ -0,0 +1,130 @@
+# Bootstrapping your users
+
+Before spawning a notebook to the user, it could be useful to 
+do some preparation work in a bootstrapping process.
+
+Common use cases are:
+
+*Providing writeable storage for LDAP users*
+
+Your Jupyterhub is configured to use the LDAPAuthenticator and DockerSpawer.
+
+* The user has no file directory on the host since your are using LDAP.
+* When a user has no directory and DockerSpawner wants to mount a volume,
+the spawner will use docker to create a directory.
+Since the docker daemon is running as root, the generated directory for the volume 
+mount will not be writeable by the `jovyan` user inside of the container. 
+For the directory to be useful to the user, the permissions on the directory 
+need to be modified for the user to have write access.
+
+*Prepopulating Content*
+
+Another use would be to copy initial content, such as tutorial files or reference
+ material, into the user's space when a notebook server is newly spawned.
+
+You can define your own bootstrap process by implementing a `pre_spawn_hook` on any spawner.
+The Spawner itself is passed as parameter to your hook and you can easily get the contextual information out of the spawning process. 
+
+If you implement a hook, make sure that it is *idempotent*. It will be executed every time 
+a notebook server is spawned to the user. That means you should somehow 
+ensure that things which should run only once are not running again and again.
+For example, before you create a directory, check if it exists.
+
+Bootstrapping examples:
+
+### Example #1 - Create a user directory
+
+Create a directory for the user, if none exists
+
+```python
+
+# in jupyterhub_config.py  
+import os
+def create_dir_hook(spawner):
+    username = spawner.user.name # get the username
+    volume_path = os.path.join('/volumes/jupyterhub', username)
+    if not os.path.exists(volume_path):
+        # create a directory with umask 0755 
+        # hub and container user must have the same UID to be writeable
+        # still readable by other users on the system
+        os.mkdir(volume_path, 0o755)
+        # now do whatever you think your user needs
+        # ...
+        pass
+
+# attach the hook function to the spawner
+c.Spawner.pre_spawn_hook = create_dir_hook
+```
+
+### Example #2 - Run a shell script 
+
+You can specify a plain ole' shell script (or any other executable) to be run 
+by the bootstrap process.
+
+For example, you can execute a shell script and as first parameter pass the name 
+of the user:
+
+```python
+
+# in jupyterhub_config.py    
+from subprocess import check_call
+import os
+def my_script_hook(spawner):
+    username = spawner.user.name # get the username
+    script = os.path.join(os.path.dirname(__file__), 'bootstrap.sh')
+    check_call([script, username])
+
+# attach the hook function to the spawner
+c.Spawner.pre_spawn_hook = my_script_hook
+
+```
+
+Here's an example on what you could do in your shell script. See also 
+`/examples/bootstrap-script/`
+
+```bash
+#!/bin/bash
+
+# Bootstrap example script
+# Copyright (c) Jupyter Development Team.
+# Distributed under the terms of the Modified BSD License.
+
+# - The first parameter for the Bootstrap Script is the USER.
+USER=$1
+if ["$USER" == ""]; then
+    exit 1
+fi
+# ----------------------------------------------------------------------------
+
+
+# This example script will do the following:
+# - create one directory for the user $USER in a BASE_DIRECTORY (see below)
+# - create a "tutorials" directory within and download and unzip 
+#   the PythonDataScienceHandbook from GitHub
+
+# Start the Bootstrap Process
+echo "bootstrap process running for user $USER ..."
+
+# Base Directory: All Directories for the user will be below this point
+BASE_DIRECTORY=/volumes/jupyterhub/
+
+# User Directory: That's the private directory for the user to be created, if none exists
+USER_DIRECTORY=$BASE_DIRECTORY/$USER
+
+if [ -d "$USER_DIRECTORY" ]; then
+    echo "...directory for user already exists. skipped"
+    exit 0 # all good. nothing to do.
+else
+    echo "...creating a directory for the user: $USER_DIRECTORY"
+    mkdir $USER_DIRECTORY
+
+    echo "...initial content loading for user ..."
+    mkdir $USER_DIRECTORY/tutorials
+    cd $USER_DIRECTORY/tutorials
+    wget https://github.com/jakevdp/PythonDataScienceHandbook/archive/master.zip
+    unzip -o master.zip
+    rm master.zip
+fi
+
+exit 0
+```

examples/bootstrap-script/bootstrap.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+
+# Bootstrap example script
+# Copyright (c) Jupyter Development Team.
+# Distributed under the terms of the Modified BSD License.
+
+# - The first parameter for the Bootstrap Script is the USER.
+USER=$1
+if ["$USER" == ""]; then
+    exit 1
+fi
+# ----------------------------------------------------------------------------
+
+
+# This example script will do the following:
+# - create one directory for the user $USER in a BASE_DIRECTORY (see below)
+# - create a "tutorials" directory within and download and unzip the PythonDataScienceHandbook from GitHub
+
+# Start the Bootstrap Process
+echo "bootstrap process running for user $USER ..."
+
+# Base Directory: All Directories for the user will be below this point
+BASE_DIRECTORY=/volumes/jupyterhub
+
+# User Directory: That's the private directory for the user to be created, if none exists
+USER_DIRECTORY=$BASE_DIRECTORY/$USER
+
+if [ -d "$USER_DIRECTORY" ]; then
+    echo "...directory for user already exists. skipped"
+    exit 0 # all good. nothing to do.
+else
+    echo "...creating a directory for the user: $USER_DIRECTORY"
+    mkdir $USER_DIRECTORY
+
+    # mkdir did not succeed?
+    if [ $? -ne 0 ] ; then
+        exit 1
+    fi
+
+    echo "...initial content loading for user ..."
+    mkdir $USER_DIRECTORY/tutorials
+    cd $USER_DIRECTORY/tutorials
+    wget https://github.com/jakevdp/PythonDataScienceHandbook/archive/master.zip
+    unzip -o master.zip
+    rm master.zip
+fi
+
+exit 0

examples/bootstrap-script/jupyterhub_config.py

@@ -0,0 +1,26 @@
+# Example for a Spawner.pre_spawn_hook
+# create a directory for the user before the spawner starts
+
+import os
+def create_dir_hook(spawner):
+    username = spawner.user.name # get the username
+    volume_path = os.path.join('/volumes/jupyterhub', username)
+    if not os.path.exists(volume_path):
+        os.mkdir(volume_path, 0o755)
+        # now do whatever you think your user needs
+        # ...
+
+# attach the hook function to the spawner
+c.Spawner.pre_spawn_hook = create_dir_hook
+
+# Use the DockerSpawner to serve your users' notebooks
+c.JupyterHub.spawner_class = 'dockerspawner.DockerSpawner'
+from jupyter_client.localinterfaces import public_ips
+c.JupyterHub.hub_ip = public_ips()[0]
+c.DockerSpawner.hub_ip_connect = public_ips()[0]
+c.DockerSpawner.container_ip = "0.0.0.0"
+
+# You can now mount the volume to the docker container as we've
+# made sure the directory exists
+c.DockerSpawner.volumes = { '/volumes/jupyterhub/{username}/': '/home/jovyan/work' }
+

jupyterhub/spawner.py

@@ -349,6 +349,27 @@ class Spawner(LoggingConfigurable):
         """
     ).tag(config=True)
 
+    pre_spawn_hook = Any(
+        None,
+        allow_none=True,
+        help="""
+        An optional hook function that you can implement to do some bootstrapping work before
+        the spawner starts. For example, create a directory for your user or load initial content.
+        
+        This can be set independent of any concrete spawner implementation.
+        
+        Example:
+        
+        from subprocess import check_call
+        def my_hook(spawner):
+            username = spawner.user.name
+            check_call(['./examples/bootstrap-script/bootstrap.sh', username])
+
+        c.Spawner.pre_spawn_hook = my_hook
+        
+        """
+    ).tag(config=True)
+
     def __init__(self, **kwargs):
         super(Spawner, self).__init__(**kwargs)
         if self.user.state:
@@ -522,6 +543,19 @@ class Spawner(LoggingConfigurable):
         args.extend(self.args)
         return args
 
+    def run_pre_spawn_hook(self):
+        """
+        run a pre spawn hook function which you can define in your jupyterhub_config.py
+        :return: void
+        """
+        if (callable(self.pre_spawn_hook)):
+            try:
+                self.pre_spawn_hook(self)
+            except Exception as e:
+                self.log.exception("pre_spawn_hook failed with exception: %s", e)
+                raise e
+        return
+
     @gen.coroutine
     def start(self):
         """Start the single-user server

jupyterhub/user.py

@@ -141,7 +141,6 @@ class User(HasTraits):
         )
 
     # pass get/setattr to ORM user
-
     def __getattr__(self, attr):
         if hasattr(self.orm_user, attr):
             return getattr(self.orm_user, attr)
@@ -165,7 +164,7 @@ class User(HasTraits):
         if self.server is None:
             return False
         return True
-    
+
     @property
     def server(self):
         if len(self.servers) == 0:
@@ -283,6 +282,9 @@ class User(HasTraits):
         if (authenticator):
             yield gen.maybe_future(authenticator.pre_spawn_start(self, spawner))
 
+        # run optional preparation work to bootstrap the notebook
+        yield gen.maybe_future(self.spawner.run_pre_spawn_hook())
+
         self.spawn_pending = True
         # wait for spawner.start to return
         try: