openstack-manuals/doc/admin-guide/source/identity-concepts.rst
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=================
Identity concepts
=================
Authentication
The process of confirming the identity of a user. To confirm an incoming
request, OpenStack Identity validates a set of credentials users
supply. Initially, these credentials are a user name and password, or a
user name and API key. When OpenStack Identity validates user credentials,
it issues an authentication token. Users provide the token in
subsequent requests.
Credentials
Data that confirms the identity of the user. For example, user
name and password, user name and API key, or an authentication
token that the Identity service provides.
Domain
An Identity service API v3 entity. Domains are a collection of
projects and users that define administrative boundaries for
managing Identity entities. Domains can represent an
individual, company, or operator-owned space. They expose
administrative activities directly to system users. Users can be
granted the administrator role for a domain. A domain
administrator can create projects, users, and groups in a domain
and assign roles to users and groups in a domain.
Endpoint
A network-accessible address, usually a URL, through which you can
access a service. If you are using an extension for templates, you
can create an endpoint template that represents the templates of
all consumable services that are available across the regions.
Group
An Identity service API v3 entity. Groups are a collection of
users owned by a domain. A group role, granted to a domain
or project, applies to all users in the group. Adding or removing
users to or from a group grants or revokes their role and
authentication to the associated domain or project.
OpenStackClient
A command-line interface for several OpenStack services including
the Identity API. For example, a user can run the
:command:`openstack service create` and
:command:`openstack endpoint create` commands to register services
in their OpenStack installation.
Project
A container that groups or isolates resources or identity objects.
Depending on the service operator, a project might map to a
customer, account, organization, or tenant.
Region
An Identity service API v3 entity. Represents a general division
in an OpenStack deployment. You can associate zero or more
sub-regions with a region to make a tree-like structured hierarchy.
Although a region does not have a geographical connotation, a
deployment can use a geographical name for a region, such as ``us-east``.
Role
A personality with a defined set of user rights and privileges to
perform a specific set of operations. The Identity service issues
a token to a user that includes a list of roles. When a user calls
a service, that service interprets the user role set, and
determines to which operations or resources each role grants
access.
Service
An OpenStack service, such as Compute (nova), Object Storage
(swift), or Image service (glance), that provides one or more
endpoints through which users can access resources and perform
operations.
Token
An alpha-numeric text string that enables access to OpenStack APIs
and resources. A token may be revoked at any time and is valid for
a finite duration. While OpenStack Identity supports token-based
authentication in this release, it intends to support additional
protocols in the future. OpenStack Identity is an integration
service that does not aspire to be a full-fledged identity store
and management solution.
User
A digital representation of a person, system, or service that uses
OpenStack cloud services. The Identity service validates that
incoming requests are made by the user who claims to be making the
call. Users have a login and can access resources by using
assigned tokens. Users can be directly assigned to a particular
project and behave as if they are contained in that project.
User management
~~~~~~~~~~~~~~~
Identity user management examples:
* Create a user named ``alice``:
.. code-block:: console
$ openstack user create --password-prompt --email alice@example.com alice
* Create a project named ``acme``:
.. code-block:: console
$ openstack project create acme
* Create a domain named ``emea``:
.. code-block:: console
$ openstack --os-identity-api-version=3 domain create emea
* Create a role named ``compute-user``:
.. code-block:: console
$ openstack role create compute-user
.. note::
Individual services assign meaning to roles, typically through
limiting or granting access to users with the role to the
operations that the service supports. Role access is typically
configured in the service's ``policy.json`` file. For example,
to limit Compute access to the ``compute-user`` role, edit the
Compute service's ``policy.json`` file to require this role for
Compute operations.
The Identity service assigns a tenant and a role to a user. You might
assign the ``compute-user`` role to the ``alice`` user in the ``acme``
tenant:
.. code-block:: console
$ openstack role add --project acme --user alice compute-user
A user can have different roles in different tenants. For example, Alice
might also have the ``admin`` role in the ``Cyberdyne`` tenant. A user
can also have multiple roles in the same tenant.
The ``/etc/[SERVICE_CODENAME]/policy.json`` file controls the
tasks that users can perform for a given service. For example, the
``/etc/nova/policy.json`` file specifies the access policy for the
Compute service, the ``/etc/glance/policy.json`` file specifies
the access policy for the Image service, and the
``/etc/keystone/policy.json`` file specifies the access policy for
the Identity service.
The default ``policy.json`` files in the Compute, Identity, and
Image services recognize only the ``admin`` role. Any user with
any role in a tenant can access all operations that do not require the
``admin`` role.
To restrict users from performing operations in, for example, the
Compute service, you must create a role in the Identity service and
then modify the ``/etc/nova/policy.json`` file so that this role
is required for Compute operations.
For example, the following line in the ``/etc/cinder/policy.json``
file does not restrict which users can create volumes:
.. code-block:: json
"volume:create": "",
If the user has any role in a tenant, he can create volumes in that
tenant.
To restrict the creation of volumes to users who have the
``compute-user`` role in a particular tenant, you add ``"role:compute-user"``:
.. code-block:: json
"volume:create": "role:compute-user",
To restrict all Compute service requests to require this role, the
resulting file looks like:
.. code-block:: json
{
"admin_or_owner": "role:admin or project_id:%(project_id)s",
"default": "rule:admin_or_owner",
"compute:create": "role:compute-user",
"compute:create:attach_network": "role:compute-user",
"compute:create:attach_volume": "role:compute-user",
"compute:get_all": "role:compute-user",
"compute:unlock_override": "rule:admin_api",
"admin_api": "role:admin",
"compute_extension:accounts": "rule:admin_api",
"compute_extension:admin_actions": "rule:admin_api",
"compute_extension:admin_actions:pause": "rule:admin_or_owner",
"compute_extension:admin_actions:unpause": "rule:admin_or_owner",
"compute_extension:admin_actions:suspend": "rule:admin_or_owner",
"compute_extension:admin_actions:resume": "rule:admin_or_owner",
"compute_extension:admin_actions:lock": "rule:admin_or_owner",
"compute_extension:admin_actions:unlock": "rule:admin_or_owner",
"compute_extension:admin_actions:resetNetwork": "rule:admin_api",
"compute_extension:admin_actions:injectNetworkInfo": "rule:admin_api",
"compute_extension:admin_actions:createBackup": "rule:admin_or_owner",
"compute_extension:admin_actions:migrateLive": "rule:admin_api",
"compute_extension:admin_actions:migrate": "rule:admin_api",
"compute_extension:aggregates": "rule:admin_api",
"compute_extension:certificates": "role:compute-user",
"compute_extension:cloudpipe": "rule:admin_api",
"compute_extension:console_output": "role:compute-user",
"compute_extension:consoles": "role:compute-user",
"compute_extension:createserverext": "role:compute-user",
"compute_extension:deferred_delete": "role:compute-user",
"compute_extension:disk_config": "role:compute-user",
"compute_extension:evacuate": "rule:admin_api",
"compute_extension:extended_server_attributes": "rule:admin_api",
"compute_extension:extended_status": "role:compute-user",
"compute_extension:flavorextradata": "role:compute-user",
"compute_extension:flavorextraspecs": "role:compute-user",
"compute_extension:flavormanage": "rule:admin_api",
"compute_extension:floating_ip_dns": "role:compute-user",
"compute_extension:floating_ip_pools": "role:compute-user",
"compute_extension:floating_ips": "role:compute-user",
"compute_extension:hosts": "rule:admin_api",
"compute_extension:keypairs": "role:compute-user",
"compute_extension:multinic": "role:compute-user",
"compute_extension:networks": "rule:admin_api",
"compute_extension:quotas": "role:compute-user",
"compute_extension:rescue": "role:compute-user",
"compute_extension:security_groups": "role:compute-user",
"compute_extension:server_action_list": "rule:admin_api",
"compute_extension:server_diagnostics": "rule:admin_api",
"compute_extension:simple_tenant_usage:show": "rule:admin_or_owner",
"compute_extension:simple_tenant_usage:list": "rule:admin_api",
"compute_extension:users": "rule:admin_api",
"compute_extension:virtual_interfaces": "role:compute-user",
"compute_extension:virtual_storage_arrays": "role:compute-user",
"compute_extension:volumes": "role:compute-user",
"compute_extension:volume_attachments:index": "role:compute-user",
"compute_extension:volume_attachments:show": "role:compute-user",
"compute_extension:volume_attachments:create": "role:compute-user",
"compute_extension:volume_attachments:delete": "role:compute-user",
"compute_extension:volumetypes": "role:compute-user",
"volume:create": "role:compute-user",
"volume:get_all": "role:compute-user",
"volume:get_volume_metadata": "role:compute-user",
"volume:get_snapshot": "role:compute-user",
"volume:get_all_snapshots": "role:compute-user",
"network:get_all_networks": "role:compute-user",
"network:get_network": "role:compute-user",
"network:delete_network": "role:compute-user",
"network:disassociate_network": "role:compute-user",
"network:get_vifs_by_instance": "role:compute-user",
"network:allocate_for_instance": "role:compute-user",
"network:deallocate_for_instance": "role:compute-user",
"network:validate_networks": "role:compute-user",
"network:get_instance_uuids_by_ip_filter": "role:compute-user",
"network:get_floating_ip": "role:compute-user",
"network:get_floating_ip_pools": "role:compute-user",
"network:get_floating_ip_by_address": "role:compute-user",
"network:get_floating_ips_by_project": "role:compute-user",
"network:get_floating_ips_by_fixed_address": "role:compute-user",
"network:allocate_floating_ip": "role:compute-user",
"network:deallocate_floating_ip": "role:compute-user",
"network:associate_floating_ip": "role:compute-user",
"network:disassociate_floating_ip": "role:compute-user",
"network:get_fixed_ip": "role:compute-user",
"network:add_fixed_ip_to_instance": "role:compute-user",
"network:remove_fixed_ip_from_instance": "role:compute-user",
"network:add_network_to_project": "role:compute-user",
"network:get_instance_nw_info": "role:compute-user",
"network:get_dns_domains": "role:compute-user",
"network:add_dns_entry": "role:compute-user",
"network:modify_dns_entry": "role:compute-user",
"network:delete_dns_entry": "role:compute-user",
"network:get_dns_entries_by_address": "role:compute-user",
"network:get_dns_entries_by_name": "role:compute-user",
"network:create_private_dns_domain": "role:compute-user",
"network:create_public_dns_domain": "role:compute-user",
"network:delete_dns_domain": "role:compute-user"
}
Service management
~~~~~~~~~~~~~~~~~~
The Identity service provides identity, token, catalog, and policy
services. It consists of:
* keystone Web Server Gateway Interface (WSGI) service
Can be run in a WSGI-capable web server such as Apache httpd to provide
the Identity service. The service and administrative APIs are run as
separate instances of the WSGI service.
* Identity service functions
Each has a pluggable back end that allow different ways to use the
particular service. Most support standard back ends like LDAP or SQL.
* keystone-all
Starts both the service and administrative APIs in a single process.
Using federation with keystone-all is not supported. keystone-all is
deprecated in favor of the WSGI service. Also, this will be removed
in Newton.
The Identity service also maintains a user that corresponds to each
service, such as, a user named ``nova`` for the Compute service, and a
special service tenant called ``service``.
For information about how to create services and endpoints, see the
`OpenStack Administrator Guide <http://docs.openstack.org/admin-guide/
cli-manage-services.html>`__.
Groups
~~~~~~
A group is a collection of users in a domain. Administrators can
create groups and add users to them. A role can then be assigned to
the group, rather than individual users. Groups were introduced with
the Identity API v3.
Identity API V3 provides the following group-related operations:
* Create a group
* Delete a group
* Update a group (change its name or description)
* Add a user to a group
* Remove a user from a group
* List group members
* List groups for a user
* Assign a role on a tenant to a group
* Assign a role on a domain to a group
* Query role assignments to groups
.. note::
The Identity service server might not allow all operations. For
example, if you use the Identity server with the LDAP Identity
back end and group updates are disabled, a request to create,
delete, or update a group fails.
Here are a couple of examples:
* Group A is granted Role A on Tenant A. If User A is a member of Group
A, when User A gets a token scoped to Tenant A, the token also
includes Role A.
* Group B is granted Role B on Domain B. If User B is a member of
Group B, when User B gets a token scoped to Domain B, the token also
includes Role B.