18. Setting up LDAP Authentication¶

Administrators use LDAP as a source for account authentication information for Tower users. User authentication is provided, but not the synchronization of user permissions and credentials. Organization membership (as well as the organization admin) and team memberships can be synchronized.

When so configured, a user who logs in with an LDAP username and password automatically gets a Tower account created for them and they can be automatically placed into organizations as either regular users or organization administrators.

Users created via an LDAP login cannot change their username, first name, last name, or set a local password for themselves. This is also tunable to restrict editing of other field names.

To configure LDAP integration for Tower:

1. First, create a user in LDAP that has access to read the entire LDAP structure.

2. Test if you can make successful queries to the LDAP server, use the ldapsearch command, which is a command line tool that can be installed on the tower system’s command line as well as on other Linux and OSX systems. Use the following command to query the ldap server, where josie and Josie4Cloud are replaced by attributes that work for your setup:

ldapsearch -x  -H ldap://win -D "CN=josie,CN=Users,DC=website,DC=com" -b "dc=website,dc=com" -w Josie4Cloud

Here CN=josie,CN=users,DC=website,DC=com is the Distinguished Name of the connecting user.

3. From the left navigation bar, click the Settings () icon.

The Authentication tab displays initially by default.

4. In the Sub Category field, select LDAP from the drop-down list.

Note

Starting with Ansible Tower 3.3, you can configure multiple LDAP servers by specifying the server to configure (otherwise, leave the server at Default):

The equivalent API endpoints will show AUTH_LDAP_* repeated: AUTH_LDAP_1_*, AUTH_LDAP_2_*, …, AUTH_LDAP_5_* to denote server designations.

5. Enter the LDAP server address to connect to in the LDAP Server URI field using the same format as the one shown in the text field. Below is an example:

6. Enter the Distinguished Name in the LDAP Bind DN text field to specify the user that Tower uses to connect (Bind) to the LDAP server. Below uses the example, CN=josie,CN=users,DC=website,DC=com:

7. Enter the password to use for the Binding user in the LDAP Bind Password text field. In this example, the password is ‘passme’:

8. If that name is stored in key sAMAccountName, the LDAP User DN Template populates with (sAMAccountName=%(user)s). Active Directory stores the username to sAMAccountName. Similarly, for OpenLDAP, the key is uid–hence the line becomes (uid=%(user)s).

9. Click to select a group type from the LDAP Group Type drop-down menu list.

LDAP Group Types include:

• PosixGroupType

• GroupOfNamesType

• GroupOfUniqueNamesType

• ActiveDirectoryGroupType

• OrganizationalRoleGroupType

• MemberDNGroupType

• NISGroupType

• NestedGroupOfNamesType

• NestedGroupOfUniqueNamesType

• NestedActiveDirectoryGroupType

• NestedOrganizationalRoleGroupType

• NestedMemberDNGroupType

• PosixUIDGroupType

The LDAP Group Types that are supported by Tower leverage the underlying django-auth-ldap library.

Each LDAP Group Type can potentially take different parameters. Tower exposes LDAP_GROUP_TYPE_PARAMS to account for this. LDAP_GROUP_TYPE_PARAMS is a dictionary, which will be converted by Tower to kwargs and passed to the LDAP Group Type class selected. There are two common parameters used by any of the LDAP Group Type; name_attr and member_attr. Where name_attr defaults to cn and member_attr defaults to member:

{"name_attr": "cn", "member_attr": "member"}

To determine what parameters a specific LDAP Group Type expects. refer to the django_auth_ldap documentation around the classes init parameters.

10. Enter the group distinguish name to allow users within that group to access Tower in the LDAP Require Group field, using the same format as the one shown in the text field. In this example, use: CN=Tower Users,OU=Users,DC=website,DC=com

11. Enter the group distinguish name to prevent users within that group to access Tower in the LDAP Deny Group field, using the same format as the one shown in the text field. In this example, leave the field blank.

12. The LDAP Start TLS is disabled by default. To enable TLS when the LDAP connection is not using SSL, click the toggle to ON.

13. Enter where to search for users while authenticating in the LDAP USER SEARCH field using the same format as the one shown in the text field. In this example, use:

[
"OU=Users,DC=website,DC=com",
"SCOPE_SUBTREE",
"(cn=%(user)s)"
]

The first line specifies where to search for users in the LDAP tree. In the above example, the users are searched recursively starting from DC=website,DC=com.

The second line specifies the scope where the users should be searched:

• SCOPE_BASE: This value is used to indicate searching only the entry at the base DN, resulting in only that entry being returned

• SCOPE_ONELEVEL: This value is used to indicate searching all entries one level under the base DN - but not including the base DN and not including any entries under that one level under the base DN.

• SCOPE_SUBTREE: This value is used to indicate searching of all entries at all levels under and including the specified base DN.

The third line specifies the key name where the user name is stored.

[
  [
  "OU=Users,DC=northamerica,DC=acme,DC=com",
  "SCOPE_SUBTREE",
  "(sAMAccountName=%(user)s)"
  ],
  [
  "OU=Users,DC=apac,DC=corp,DC=com",
  "SCOPE_SUBTREE",
  "(sAMAccountName=%(user)s)"
  ],
  [
  "OU=Users,DC=emea,DC=corp,DC=com",
  "SCOPE_SUBTREE",
  "(sAMAccountName=%(user)s)"
  ]
]

14. In the LDAP Group Search text field, specify which groups should be searched and how to search them. In this example, use:

 [
"dc=example,dc=com",
"SCOPE_SUBTREE",
"(objectClass=group)"
 ]

• The first line specifies the BASE DN where the groups should be searched.

• The second lines specifies the scope and is the same as that for the user directive.

• The third line specifies what the objectclass of a group object is in the LDAP you are using.

15. Enter the user attributes in the LDAP User Attribute Map the text field. In this example, use:

{
"first_name": "givenName",
"last_name": "sn",
"email": "mail"
}

The above example retrieves users by last name from the key sn. You can use the same LDAP query for the user to figure out what keys they are stored under.

16. Enter the user profile flags in the LDAP User Flags by Group the text field. In this example, use the following syntax to set LDAP users as “Superusers” and “Auditors”:

{
"is_superuser": "cn=superusers,ou=groups,dc=website,dc=com"
"is_system_auditor": "cn=auditors,ou=groups,dc=website,dc=com"
}

The above example retrieves users who are flagged as superusers or as auditor in their profile.

17. For details on completing the mapping fields, see LDAP Organization and Team Mapping.

18. Click Save when done.

With these values entered on this form, you can now make a successful authentication with LDAP.

AUTH_LDAP_GLOBAL_OPTIONS = {
    ldap.OPT_REFERRALS: False,
}

LOGGING['handlers']['tower_warnings']['level'] =  'DEBUG'

{
"LDAP Organization": {
  "admins": "cn=engineering_admins,ou=groups,dc=example,dc=com",
  "remove_admins": false,
  "users": [
    "cn=engineering,ou=groups,dc=example,dc=com",
    "cn=sales,ou=groups,dc=example,dc=com",
    "cn=it,ou=groups,dc=example,dc=com"
  ],
  "remove_users": false
},
"LDAP Organization 2": {
  "admins": [
    "cn=Administrators,cn=Builtin,dc=example,dc=com"
  ],
  "remove_admins": false,
  "users": true,
  "remove_users": false
}
}

{
"LDAP Engineering": {
  "organization": "LDAP Organization",
  "users": "cn=engineering,ou=groups,dc=example,dc=com",
  "remove": true
},
"LDAP IT": {
  "organization": "LDAP Organization",
  "users": "cn=it,ou=groups,dc=example,dc=com",
  "remove": true
},
"LDAP Sales": {
  "organization": "LDAP Organization",
  "users": "cn=sales,ou=groups,dc=example,dc=com",
  "remove": true
}
}