Using LDAP authentication

NOTE: this is a (modified) copy of the NetBox LDAP installation document.

This guide explains how to implement optional LDAP authentication using an external server. User authentication will fall back to built-in Django users in the event of a failure.

If you do NOT want to enable this feature, and only use local application accounts, simple ignore the rest of this page!

Requirements

All OS pre-requisites should be already installed. You need to manually install the Python requirements the first time around.

source venv/bin/activate
pip3 install django-auth-ldap

Next, modify or create the file local_requirements.txt to allow this to be added automatically during future upgrades:

sudo sh -c "echo 'django-auth-ldap>=4.2.0' >> local_requirements.txt"

Configuration

Create a file in the same directory as configuration.py (typically OpenL2M/OpenL2M/) named ldap_config.py. Define all of the parameters required below in ldap_config.py. Complete documentation of all django-auth-ldap configuration options is included in the project’s official documentation at http://django-auth-ldap.readthedocs.io/.

General Server Configuration

NOTE: When using Windows Server you may need to specify a port on AUTH_LDAP_SERVER_URI. Use 3269 for secure, or 3268 for non-secure:

import ldap

# Server URI
AUTH_LDAP_SERVER_URI = "ldaps://ad.example.com"

# The following may be needed if you are binding to Active Directory.
AUTH_LDAP_CONNECTION_OPTIONS = {
    ldap.OPT_REFERRALS: 0
}

# Set the DN and password for the OpenL2M service account.
AUTH_LDAP_BIND_DN = "CN=openl2m, OU=Service Accounts,DC=example,DC=com"
AUTH_LDAP_BIND_PASSWORD = "demo"

# Include this setting if you want to ignore certificate errors. This might be needed to accept a self-signed cert.
# Note that this is a OpenL2M-specific setting which sets:
#     ldap.set_option(ldap.OPT_X_TLS_REQUIRE_CERT, ldap.OPT_X_TLS_NEVER)
LDAP_IGNORE_CERT_ERRORS = True
``

STARTTLS can be configured by setting AUTH_LDAP_START_TLS = True and using the ldap:// URI scheme.

User Authentication

NOTE: When using Windows Server, AUTH_LDAP_USER_DN_TEMPLATE should be set to None:

from django_auth_ldap.config import LDAPSearch

# This search matches users with the sAMAccountName equal to the provided username. This is required if the user's
# username is not in their DN (Active Directory).
AUTH_LDAP_USER_SEARCH = LDAPSearch("ou=Users,dc=example,dc=com",
                                    ldap.SCOPE_SUBTREE,
                                    "(sAMAccountName=%(user)s)")

# If a user's DN is producible from their username, we don't need to search.
AUTH_LDAP_USER_DN_TEMPLATE = "uid=%(user)s,ou=users,dc=example,dc=com"

# You can map user attributes to Django attributes as so.
AUTH_LDAP_USER_ATTR_MAP = {
    "first_name": "givenName",
    "last_name": "sn",
    "email": "mail"
}

User Groups for Permissions

NOTE: When using Microsoft Active Directory, support for nested groups can be activated by using NestedGroupOfNamesType() instead of GroupOfNamesType() for AUTH_LDAP_GROUP_TYPE. You will also need to modify the import line to use NestedGroupOfNamesType instead of GroupOfNamesType

LDAP Groups can be used to create SwitchGroup() objects. See the configuration section for more:

from django_auth_ldap.config import LDAPSearch, GroupOfNamesType

# This search ought to return all groups to which the user belongs. django_auth_ldap uses this to determine group
# hierarchy.
AUTH_LDAP_GROUP_SEARCH = LDAPSearch("dc=example,dc=com", ldap.SCOPE_SUBTREE,
                                    "(objectClass=group)")
AUTH_LDAP_GROUP_TYPE = GroupOfNamesType()

# Define a group required to login.
AUTH_LDAP_REQUIRE_GROUP = "CN=OpenL2M_USERS,DC=example,DC=com"

# Do NOT Mirror LDAP group assignments, we DO NOT use them!
AUTH_LDAP_MIRROR_GROUPS = False

# Define special user types using groups. Exercise great caution when assigning superuser status.
AUTH_LDAP_USER_FLAGS_BY_GROUP = {
    "is_active": "cn=active,ou=groups,dc=example,dc=com",
    "is_staff": "cn=staff,ou=groups,dc=example,dc=com",
    "is_superuser": "cn=superuser,ou=groups,dc=example,dc=com"
}

# For more granular permissions, we can map LDAP groups to Django groups.
AUTH_LDAP_FIND_GROUP_PERMS = True

# Cache groups for one hour to reduce LDAP traffic
AUTH_LDAP_CACHE_GROUPS = True
AUTH_LDAP_GROUP_CACHE_TIMEOUT = 3600

is_active - All users must be mapped to at least this group to enable authentication. Without this, users cannot log in.
is_staff - Users mapped to this group are enabled for access to the administration tools; this is the equivalent of checking the “staff status” box on a manually created user. This doesn’t grant any specific permissions.
is_superuser - Users mapped to this group will be granted superuser status. Superusers are implicitly granted all permissions.

Troubleshooting LDAP

Restart the OpenL2M service to initiate changes made to ldap_config.py:

sudo systemctl restart openl2m

If there are syntax errors present, the OpenL2M process will not spawn an instance, and errors should show with systemctl status openl2m

For troubleshooting LDAP user/group queries, add the following lines to the start of ldap_config.py after import ldap:

import logging, logging.handlers
logfile = "/opt/openl2m/logs/django-ldap-debug.log"
my_logger = logging.getLogger('django_auth_ldap')
my_logger.setLevel(logging.DEBUG)
handler = logging.handlers.RotatingFileHandler(
   logfile, maxBytes=1024 * 500, backupCount=5)
my_logger.addHandler(handler)

Ensure the file and path specified in logfile exist and are writable and executable by the application service account. Restart the OpenL2M service and attempt to log into the site to trigger log entries to this file.