Tutorial: ldap3 Abstraction Layer - Writing data

Writing entries

Modifying data on an LDAP server is easy with the Abstraction Layer, just add a new Entry with its Attribute values (or change the Attribute values of an existing Entry) and commit the pending changes to the DIT via the Writer cursor. You can obtain a Writer cursor in a number of ways:

  • from a Reader Cursor, using the Writer.from_cursor() static method that populates the entries collection with a copy of the Entries from the Reader cursor.
  • from a Search response, using the Writer.from_response() static method, that populates the entries collection with a copy of the Entries from the Search response.
  • from a single Entry in a Reader cursor, using the entry_writable() method of the Entry, that returns a new Writable Entry (and also creates its Writer cursor).
  • from a single Entry in a Search response, using the entry_writable() method of the Entry, that returns a new Writable Entry (and also creates its Writer cursor)
  • as a new instance of the ldap3.abstract.Writer class, using Writer() that creates a new Writer cursor with an empty entries collection. With this cursor you can only create new Entries.

Let’s obtain a Writer cursor from the inetOrgPerson Reader we used in the previous chapter:

>>> r = Reader(conn, obj_inetorgperson, 'ou=ldap3-tutorial,dc=demo1,dc=freeipa,dc=org')
>>> r.search()
>>> w = Writer.from_cursor(r)
>>> w
CURSOR : Writer
CONN   : ldap://ipa.demo1.freeipa.org:389 - cleartext - user: uid=admin,cn=users,cn=accounts,dc=demo1,dc=freeipa,dc=org - not lazy - bound - open - <local: 10.3.9.227:29872 - remote: 209.132.178.99:389> - tls not started - listening - SyncStrategy - internal decoder
DEFS   : ['inetOrgPerson'] [audio, businessCategory, carLicense, cn, departmentNumber, description, destinationIndicator, displayName, employeeNumber, employeeType, facsimileTelephoneNumber, givenName, homePhone, homePostalAddress, initials, internationalISDNNumber, jpegPhoto, l, labeledURI, mail, manager, mobile, o, objectClass, ou, pager, photo, physicalDeliveryOfficeName, postOfficeBox, postalAddress, postalCode, preferredDeliveryMethod, preferredLanguage, registeredAddress, roomNumber, secretary, seeAlso, sn, st, street, telephoneNumber, teletexTerminalIdentifier, telexNumber, title, uid, userCertificate, userPKCS12, userPassword, userSMIMECertificate, x121Address, x500UniqueIdentifier]
ATTRS  : ['audio', 'businessCategory', 'carLicense', 'cn', 'departmentNumber', 'description', 'destinationIndicator', 'displayName', 'employeeNumber', 'employeeType', 'facsimileTelephoneNumber', 'givenName', 'homePhone', 'homePostalAddress', 'initials', 'internationalISDNNumber', 'jpegPhoto', 'l', 'labeledURI', 'mail', 'manager', 'mobile', 'o', 'objectClass', 'ou', 'pager', 'photo', 'physicalDeliveryOfficeName', 'postOfficeBox', 'postalAddress', 'postalCode', 'preferredDeliveryMethod', 'preferredLanguage', 'registeredAddress', 'roomNumber', 'secretary', 'seeAlso', 'sn', 'st', 'street', 'telephoneNumber', 'teletexTerminalIdentifier', 'telexNumber', 'title', 'uid', 'userCertificate', 'userPKCS12', 'userPassword', 'userSMIMECertificate', 'x121Address', 'x500UniqueIdentifier']
ENTRIES: 3 [executed at: 2016-11-09T14:24:49.374675]

Entries in a Writer cursor are standard Python object, so you can modify them with standard Python code:

>>> w[0]
DN: cn=b.young,ou=ldap3-tutorial,dc=demo1,dc=freeipa,dc=org - STATUS: Writable - READ TIME: 2016-11-09T14:26:03.866351
    cn: b.young
    departmentNumber: DEV
    givenName: Beatrix
    objectClass: inetOrgPerson
                 organizationalPerson
                 person
                 top
    sn: Young
    telephoneNumber: 1111

The entry is in Writable status now, so you can try to update some values. All modifications are stored in memory until committed or the entry is returned to its original values:

>>> w[0].sn += 'Smyth'  # Add 'Smith' value from the sn
>>> w[0].sn += 'Johnson'  # Add 'Johnson' value from the sn
>>> w[0].sn -= 'Young'  # remove the 'Young' value from the sn

Now let’s revise the modifications we have requested:

>>> w[0].entry_changes
OrderedDict([('sn', [('MODIFY_ADD', ['Smyth']), ('MODIFY_ADD', ['Johnson']), ('MODIFY_DELETE', ['Young'])])])

Modifications to an Entry are stored in a way (OrderedDict) that preserves the insertion sequence. This can be helpful with specific LDAP operations that request that an attribute is modified before an other one in the same LDAP operation

We made a typo so discard the changes and insert the correct values:

>>> w[0].sn.discard()
>>> w[0].sn += ['Smith', 'Johnson']  # add a list of values
>>> w[0].sn -= 'Young'  # remove the 'Young' value from the sn
>>> w[0]
DN: cn=b.young,ou=ldap3-tutorial,dc=demo1,dc=freeipa,dc=org - STATUS: Writable, Pending changes - READ TIME: 2016-11-09T14:30:43.181520
    cn: b.young
    departmentNumber: DEV
    givenName: Beatrix
    objectClass: inetOrgPerson
                 organizationalPerson
                 person
                 top
    sn: Young
        CHANGES: [('MODIFY_ADD', ['Smith', 'Johnson']), ('MODIFY_DELETE', ['Young'])]
    telephoneNumber: 1111

Entry status is set to Writable, Pending changes, this means that mandatory Attributes are set and the Entry can be written in the DIT:

>>> w.commit()  # commit all entries with pending changes
>>> w[0]
DN: cn=b.young,ou=ldap3-tutorial,dc=demo1,dc=freeipa,dc=org - STATUS: Writable, Committed - READ TIME: 2016-11-09T14:32:14.377498
    cn: b.young
    departmentNumber: DEV
    givenName: Beatrix
    objectClass: inetOrgPerson
                 organizationalPerson
                 person
                 top
    sn: Smith
        Johnson
    telephoneNumber: 1111

Entry has been written on the DIT and its state is now Writable, Committed. If you look at the original Entry in the Reader you will find that it’s been updated with the new values:

>>> r[0]
DN: cn=b.young,ou=ldap3-tutorial,dc=demo1,dc=freeipa,dc=org - STATUS: Read - READ TIME: 2016-11-09T14:32:14.377498
    cn: b.young
    departmentNumber: DEV
    givenName: Beatrix
    objectClass: inetOrgPerson
                 organizationalPerson
                 person
                 top
    sn: Smith
        Johnson
    telephoneNumber: 1111

Refreshing of the original Entry is triggered only if both cursors are using the same Server object. If you use the Writer cursor to copy Entries to another LDAP server refreshing of the original Entry is not executed.

For specific types (boolean, integers and dates) you can set the value to the relevant Python type. The ldap3 library will perform the necessary conversion to the value expected from the LDAP server.