Home OpenStack-Ansible Installation Guide
The following is the configuration steps necessary to reproduce the federation scenario described below:
The following is the configuration for the keystone IdP instance:
keystone_idp:
certfile: "/etc/keystone/ssl/idp_signing_cert.pem"
keyfile: "/etc/keystone/ssl/idp_signing_key.pem"
self_signed_cert_subject: "/C=US/ST=Texas/L=San Antonio/O=IT/CN={{ external_lb_vip_address }}"
regen_cert: false
idp_entity_id: "{{ keystone_service_publicurl_v3 }}/OS-FEDERATION/saml2/idp"
idp_sso_endpoint: "{{ keystone_service_publicurl_v3 }}/OS-FEDERATION/saml2/sso"
idp_metadata_path: /etc/keystone/saml2_idp_metadata.xml
service_providers:
- id: "cloud2"
auth_url: https://cloud2.com:5000/v3/OS-FEDERATION/identity_providers/cloud1/protocols/saml2/auth
sp_url: https://cloud2.com:5000/Shibboleth.sso/SAML2/ECP
In this example, the last three lines are specific to a particular installation, as they reference the service provider cloud (referred to as “Cloud 2” in the original scenario). In the example, the cloud is located at https://cloud2.com, and the unique ID for this cloud is “cloud2”.
Note
In the auth_url there is a reference to the IdP cloud (or “Cloud 1”), as known by the service provider (SP). The ID used for the IdP cloud in this example is “cloud1”.
The configuration for keystone SP needs to define the remote-to-local user mappings. The following is the complete configuration:
keystone_sp:
cert_duration_years: 5
trusted_dashboard_list:
- "https://{{ external_lb_vip_address }}/auth/websso/"
trusted_idp_list:
- name: "cloud1"
entity_ids:
- 'https://cloud1.com:5000/v3/OS-FEDERATION/saml2/idp'
metadata_uri: 'https://cloud1.com:5000/v3/OS-FEDERATION/saml2/metadata'
metadata_file: 'metadata-cloud1.xml'
metadata_reload: 1800
federated_identities:
- domain: Default
project: X
role: R
group: federated_group_1
- domain: Default
project: Y
role: S
group: federated_group_2
protocols:
- name: saml2
mapping:
name: cloud1-mapping
rules:
- remote:
- any_one_of:
- A
type: openstack_project
local:
- group:
name: federated_group_1
domain:
name: Default
- remote:
- any_one_of:
- B
type: openstack_project
local:
- group:
name: federated_group_2
domain:
name: Default
attributes:
- name: openstack_user
id: openstack_user
- name: openstack_roles
id: openstack_roles
- name: openstack_project
id: openstack_project
- name: openstack_user_domain
id: openstack_user_domain
- name: openstack_project_domain
id: openstack_project_domain
cert_duration_years is for the self-signed certificate used by Shibboleth. Only implement the trusted_dashboard_list if horizon SSO login is necessary. When given, it works as a security measure, as keystone will only redirect to these URLs.
Configure the IdPs known to SP in trusted_idp_list. In this example there is only one IdP, the “Cloud 1”. Configure “Cloud 1” with the ID “cloud1”. This matches the reference in the IdP configuration shown in the previous section.
The entity_ids is given the unique URL that represents the “Cloud 1” IdP. For this example, it is hosted at: https://cloud1.com.
The metadata_file needs to be different for each IdP. This is a filename in the keystone containers of the SP cloud that holds cached metadata for each registered IdP.
The federated_identities list defines the sets of identities in use for federated users. In this example there are two sets, Project X/Role R and Project Y/Role S. A user group is created for each set.
The protocols section is where the federation protocols are specified. The only supported protocol is saml2.
The mapping dictionary is where the assignments of remote to local users is defined. A keystone mapping is given a name and a set of rules that keystone applies to determine how to map a given user. Each mapping rule has a remote and a local component.
The remote part of the mapping rule specifies the criteria for the remote user based on the attributes exposed by the IdP in the SAML2 assertion. The use case for this scenario calls for mapping users in “Group A” and “Group B”, but the group or groups a user belongs to are not exported in the SAML2 assertion. To make the example work, the groups A and B in the use case are projects. Export projects A and B in the assertion under the openstack_project attribute. The two rules above select the corresponding project using the any_one_of selector.
The local part of the mapping rule specifies how keystone represents the remote user in the local SP cloud. Configuring the two federated identities with their own user group maps the user to the corresponding group. This exposes the correct domain, project, and role.
Note
Keystone creates a ephemeral user in the specified group as you cannot specify user names.
The IdP exports the final setting of the configuration defines the SAML2 attributes. For a keystone IdP, these are the five attributes shown above. Configure the attributes above into the Shibboleth service. This ensures they are available to use in the mappings.
Use OpenStack command line client to review or make modifications to an existing federation configuration. The following commands can be used for the previous configuration.
To see the list of known SPs:
$ openstack service provider list
+--------+---------+-------------+-----------------------------------------------------------------------------------------+
| ID | Enabled | Description | Auth URL |
+--------+---------+-------------+-----------------------------------------------------------------------------------------+
| cloud2 | True | None | https://cloud2.com:5000/v3/OS-FEDERATION/identity_providers/cloud1/protocols/saml2/auth |
+--------+---------+-------------+-----------------------------------------------------------------------------------------+
To view the information for a specific SP:
$ openstack service provider show cloud2
+--------------------+----------------------------------------------------------------------------------------------+
| Field | Value |
+--------------------+----------------------------------------------------------------------------------------------+
| auth_url | http://cloud2.com:5000/v3/OS-FEDERATION/identity_providers/keystone-idp/protocols/saml2/auth |
| description | None |
| enabled | True |
| id | cloud2 |
| relay_state_prefix | ss:mem: |
| sp_url | http://cloud2.com:5000/Shibboleth.sso/SAML2/ECP |
+--------------------+----------------------------------------------------------------------------------------------+
To make modifications, use the set command. The following are the available options for this command:
$ openstack service provider set
usage: openstack service provider set [-h] [--auth-url <auth-url>]
[--description <description>]
[--service-provider-url <sp-url>]
[--enable | --disable]
<service-provider>
To see the list of known IdPs:
$ openstack identity provider list
+----------------+---------+-------------+
| ID | Enabled | Description |
+----------------+---------+-------------+
| cloud1 | True | None |
+----------------+---------+-------------+
To view the information for a specific IdP:
$ openstack identity provider show keystone-idp
+-------------+--------------------------------------------------------+
| Field | Value |
+-------------+--------------------------------------------------------+
| description | None |
| enabled | True |
| id | cloud1 |
| remote_ids | [u'http://cloud1.com:5000/v3/OS-FEDERATION/saml2/idp'] |
+-------------+--------------------------------------------------------+
To make modifications, use the set command. The following are the available options for this command:
$ openstack identity provider set
usage: openstack identity provider set [-h]
[--remote-id <remote-id> | --remote-id-file <file-name>]
[--enable | --disable]
<identity-provider>
You can use the OpenStack commandline client to view or modify the created domain, project, role, group, and user entities for the purpose of federation as these are regular keystone entities. For example:
$ openstack domain list
$ openstack project list
$ openstack role list
$ openstack group list
$ openstack user list
Add the --domain option when using a domain other than the default. Use the set option to modify these entities.
To view the list of mappings:
$ openstack mapping list
+------------------+
| ID |
+------------------+
| cloud1-mapping |
+------------------+
To view a mapping in detail:
..code:
$ openstack mapping show cloud1-mapping
+-------+--------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-------+--------------------------------------------------------------------------------------------------------------------------------------------------+
| id | keystone-idp-mapping-2 |
| rules | [{"remote": [{"type": "openstack_project", "any_one_of": ["A"]}], "local": [{"group": {"domain": {"name": "Default"}, "name": |
| | "federated_group_1"}}]}, {"remote": [{"type": "openstack_project", "any_one_of": ["B"]}], "local": [{"group": {"domain": {"name": "Default"}, |
| | "name": "federated_group_2"}}]}] |
+-------+--------------------------------------------------------------------------------------------------------------------------------------------------+
To edit a mapping, use an auxiliary file. Save the JSON mapping shown above and make the necessary modifications. Use the``set`` command to trigger an update. For example:
$ openstack mapping show cloud1-mapping -c rules -f value | python -m json.tool > rules.json
$ vi rules.json # <--- make any necessary changes
$ openstack mapping set cloud1-mapping --rules rules.json
To view or change the association between a federation protocol and a mapping, use the following command:
$ openstack federation protocol list --identity-provider keystone-idp
+-------+----------------+
| id | mapping |
+-------+----------------+
| saml2 | cloud1-mapping |
+-------+----------------+