openstack-ansible-os_keystone/doc/source/configure-federation-mapping.rst

Configure keystone mappings

The federated_identities functionality can be used to create projects, groups, roles and domains before your federation attribute mappings route users towards those resources. If you manage creation of projects, groups, roles and domains via a separate mechanism making use of federated_identities is not required.

federated_identities:
  - domain: default
    project: fedproject
    group: fedgroup
    role: _member_

1. project: The project that federation users have access to. If the project does not already exist, create it in the domain with the name, domain.
2. group: The keystone group that federation users belong. If the group does not already exist, create it in the domain with the name, domain.
3. role: The role that federation users use in that project. Create the role if it does not already exist.
4. domain: The domain where the project lives, and where the you assign roles. Create the domain if it does not already exist. This should be the ID of the domain.

Ansible implements the equivalent of the following OpenStack CLI commands:

# if the domain does not already exist
openstack domain create Default

# if the group does not already exist
openstack group create fedgroup --domain Default

# if the role does not already exist
openstack role create _member_

# if the project does not already exist
openstack project create --domain default fedproject

# map the role to the project and user group in the domain
openstack role add --project fedproject --group fedgroup _member_

To extend simply add more entries to the list. For example:

federated_identities:
  - domain: default
    project: fedproject
    group: fedgroup
    role: _member_
  - domain: default
    project: fedproject2
    group: fedgroup2
    role: _member_

Keystone federation attribute mapping

Attribute mapping adds a set of rules to map federation attributes to keystone users and groups. IdP specifies one mapping per protocol.

Use mapping objects multiple times by different combinations of IdP and protocol.

The details of how the mapping engine works, the schema, and various rule examples are in the keystone developer documentation.

For example, SP attribute mapping configuration for an ADFS IdP:

mapping:
  name: adfs-IdP-mapping
  rules:
    - remote:
        - type: upn
      local:
        - group:
            name: fedgroup
            domain:
              name: Default
        - user:
            name: '{0}'
attributes:
  - name: 'http://schemas.xmlsoap.org/ws/2005/05/identity/claims/upn'
    id: upn

Each IdP for an SP needs to be set up with a mapping. This tells the SP how to interpret the attributes provided to the SP from the IdP.

In this example, the IdP publishes the upn attribute. As this is not in the standard Shibboleth attribute map (see /etc/shibboleth/attribute-map.xml in the keystone containers), the configuration of the IdP has extra mapping through the attributes dictionary.

The mapping dictionary is a YAML representation similar to the keystone mapping property which Ansible uploads. The above mapping produces the following in keystone.

root@aio1_keystone_container-783aa4c0:~# openstack mapping list
+------------------+
| ID               |
+------------------+
| adfs-IdP-mapping |
+------------------+

root@aio1_keystone_container-783aa4c0:~# openstack mapping show adfs-IdP-mapping
+-------+---------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value                                                                                                                                 |
+-------+---------------------------------------------------------------------------------------------------------------------------------------+
| id    | adfs-IdP-mapping                                                                                                                      |
| rules | [{"remote": [{"type": "upn"}], "local": [{"group": {"domain": {"name": "Default"}, "name": "fedgroup"}}, {"user": {"name": "{0}"}}]}] |
+-------+---------------------------------------------------------------------------------------------------------------------------------------+

root@aio1_keystone_container-783aa4c0:~# openstack mapping show adfs-IdP-mapping | awk -F\| '/rules/ {print $3}' | python -mjson.tool
[
    {
        "remote": [
            {
                "type": "upn"
            }
        ],
        "local": [
            {
                "group": {
                    "domain": {
                        "name": "Default"
                    },
                    "name": "fedgroup"
                }
            },
            {
                "user": {
                    "name": "{0}"
                }
            }
        ]
    }
]

The interpretation of the above mapping rule is that any federation user authenticated by the IdP maps to an ephemeral user in keystone. The user is a member of a group named fedgroup. This is in a domain called Default. As we have specified the domain, the users assignments in the keystone backend will be looked up alongside the assignments made in the mapping. The user's ID and Name (federation uses the same value for both properties) for all OpenStack services is the value of upn.