ldap-hooks 0.1.0

Installation

Installation from pypi:

pip install ldap-hooks

Installation from local git repository:

cd ldap_hooks
pip install .

Configuration

You should edit your jupyterhub_config.py config file to set a particular pre_spawn_hook, E.g:

from ldap_hooks import hello_hook

c.Spawner.pre_spawn_hook = hello_hook

In addition to specifying the pre_spawn_hook, a set of connection parameters must be set in order for the JupyterHub server to be able to interact with the designated LDAP host:

from ldap_hooks import LDAP

LDAP.url = "openldap"
LDAP.user = "cn=admin,dc=example,dc=org"
LDAP.password = "dummyldap_password"
LDAP.base_dn = "dc=example,dc=org"

The user’s permissions here depend on whether the hook is just extracting information, or is creating entries as well.

The hooks that this library provides can be found below.

By default, any of these hooks are called by the Spawner with the following syntax:

def hook(spawner):
    # Do stuff inside the hook
    return True

That is, the hook expects that the current spawner instance is passed to it, which it can subsequently use to access properties of it, such as the user instance.

Basic Configuration

First, to defined the following options, the LDAP class must be imported into the jupyterhub_config.py file:

from ldap_hooks import LDAP

With this completed, the submit_spawner_attribute must be set, this must point to the variable path in the spawner instance where it can find the Distinguished Name String (DN) value. This string value makes up the entry that is to be submitted to the LDAP DIT, E.g:

# Retrieve the Distinguished Name from the 'spawner.user.data' variable
LDAP.submit_spawner_attribute = 'user.data'

In addition if this variable is of a dictionary structure, a tuple row can be specified to define the set of keys that should be used to extract the Distinguished Name value. For instance, if the value is in the spawner.user.data[‘User’][‘DN’] structure:

# Extract the Distinguished Name string from the
# spawner.user.data['User']['DN'] path.
LDAP.submit_spawner_attribute = 'user.data'
LDAP.submit_spawner_attribute_keys = ('User', 'DN')

If this extracted string is formatted in a way that is incorrectly seperated, the replace_object_with parameter can be used to fix this, E.g.:

# Prepare LDAP DN object entry
LDAP.replace_object_with = {'/': '+'}
# Does the following replacement
# /telephoneNumber=23012303403/SN=My Surname/CN=a-new-user
# +telephoneNumber=23012303403+SN=My Surname+CN=a-new-user

By default the name_strip_chars parameter is defined to strip extra characters that are either pre or postfixed to the DN:

# Default value
LDAP.name_strip_chars = ['/', '+', '*', ',', '.', '!', ' ']

Which means that it will automatically strip the prefixed + from the replace_object_with output.

Before the hook can submit the prepared DN, it first has to know which Structural ObjectClass should be used to create the entry with. Beyond at least one required Structural ObjectClass, a list of additional Auxiliary ObjectClasses can be specified as well. All of which must be set via the object_classes parameter, E.g:

# Structural 'Person'
LDAP.object_classes = ['Person']

Any specified object class must be supported as part of the specified LDAP.url server schema.

Beyond the object_classes, the hook also provides a parameter to specify additional object attributes to submittet DN entry:

LDAP.object_attributes = {'description': 'A default person account',
                          'surname': 'MySurname'}

Duplicate entries can be default not exist in the LDAP DIT, therefore any duplicate DN submission will fail. By default the hook will search the DIT for an entry that matches every attribute of the DN string, if such an entry exists, the hook will simply stop before attempting to submit it. This behaviour can be customised via the unique_object_attributes parameter as shown in the “Extra Features” section.

Extra Features

# Optional parameter
LDAP.unique_object_attributes = ['surname']

# Set Spawned Notebook environment vars
LDAP.set_spawner_attributes = {
    'environment': {'ENV_VAR': 'Hello from LDAP Hook'}
}

LDAP.search_attribute_queries = [
    {'search_base': LDAP.base_dn,
    'search_filter': '(objectclass=X-nextUserIdentifier)',
    'attributes': ['uidNumber']}
]

modify_dn = 'cn=uidNumber' + ',' + LDAP.base_dn
LDAP.search_result_operation = {'uidNumber': {'action': INCREMENT_ATTRIBUTE,
                                            'modify_dn': modify_dn}}

LDAP.set_spawner_attributes = {
    'environment': {'NB_USER': '{emailAddress}',
                    'NB_UID': '{uidNumber}'},
}

LDAP.dynamic_attributes = {
    'emailAddress': SPAWNER_SUBMIT_DATA,
    'uidNumber': LDAP_SEARCH_ATTRIBUTE_QUERY
}

LDAP.object_attributes = {'uidNumber': '{uidNumber}',
                          'homeDirectory': '/home/{emailAddress}'}