openstack-manuals/doc/common/section_keystone-concepts.xml
Diane Fleming 64b6c9261e Folder rename, file rename, flattening of directories
Current folder name	New folder name	        Book title
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basic-install 	        DELETE
cli-guide	        DELETE
common	                common
NEW	                admin-guide-cloud	Cloud Administrators Guide
docbkx-example	        DELETE
openstack-block-storage-admin 	DELETE
openstack-compute-admin 	DELETE
openstack-config 	config-reference	OpenStack Configuration Reference
openstack-ha 	        high-availability-guide	OpenStack High Availabilty Guide
openstack-image	        image-guide	OpenStack Virtual Machine Image Guide
openstack-install 	install-guide	OpenStack Installation Guide
openstack-network-connectivity-admin 	admin-guide-network 	OpenStack Networking Administration Guide
openstack-object-storage-admin 	DELETE
openstack-security 	security-guide	OpenStack Security Guide
openstack-training 	training-guide	OpenStack Training Guide
openstack-user 	        user-guide	OpenStack End User Guide
openstack-user-admin 	user-guide-admin	OpenStack Admin User Guide
glossary	        NEW        	OpenStack Glossary

bug: #1220407

Change-Id: Id5ffc774b966ba7b9a591743a877aa10ab3094c7
author: diane fleming
2013-09-08 15:15:50 -07:00

374 lines
19 KiB
XML

<?xml version="1.0" encoding="utf-8"?>
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0"
xml:id="keystone-concepts">
<?dbhtml stop-chunking?>
<title>Identity Service concepts</title>
<para>The Identity Service performs the following functions:</para>
<itemizedlist spacing="compact">
<listitem>
<para>User management. Tracks users and their permissions.</para>
</listitem>
<listitem>
<para>Service catalog. Provides a catalog of available
services with their API endpoints.</para>
</listitem>
</itemizedlist>
<para>To understand the Identity Service, you must understand the
following concepts:</para>
<variablelist>
<varlistentry>
<term>User</term>
<listitem>
<para>Digital representation of a person, system, or service
who uses OpenStack cloud services. Identity authentication
services will validate that incoming request are being made
by the user who claims to be making the call. Users have a
login and may be assigned tokens to access resources. Users
may be directly assigned to a particular tenant and behave
as if they are contained in that tenant.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Credentials</term>
<listitem>
<para>Data that is known only by a user that proves
who they are. In the Identity Service, examples
are:</para>
<itemizedlist>
<listitem>
<para>Username and password</para>
</listitem>
<listitem>
<para>Username and API key</para>
</listitem>
<listitem>
<para>An authentication token provided by the
Identity Service</para>
</listitem>
</itemizedlist>
</listitem>
</varlistentry>
<varlistentry>
<term>Authentication</term>
<listitem>
<para>The act of confirming the identity of a user.
The Identity Service confirms an incoming request
by validating a set of credentials supplied by the
user. These credentials are initially a username
and password or a username and API key. In
response to these credentials, the Identity
Service issues the user an authentication token,
which the user provides in subsequent requests.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Token</term>
<listitem>
<para>An arbitrary bit of text that is used to access
resources. Each token has a scope which describes
which resources are accessible with it. A token
may be revoked at any time and is valid for a
finite duration.</para>
<para>While the Identity Service supports token-based
authentication in this release, the intention is
for it to support additional protocols in the
future. The intent is for it to be an integration
service foremost, and not aspire to be a
full-fledged identity store and management
solution.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Tenant</term>
<listitem>
<para>A container used to group or isolate resources
and/or identity objects. Depending on the service
operator, a tenant may map to a customer, account,
organization, or project.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Service</term>
<listitem>
<para>An OpenStack service, such as Compute (Nova),
Object Storage (Swift), or Image Service (Glance).
Provides one or more endpoints through which users
can access resources and perform operations.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Endpoint</term>
<listitem>
<para>An network-accessible address, usually described
by URL, from where you access a service. If using
an extension for templates, you can create an
endpoint template, which represents the templates
of all the consumable services that are available
across the regions.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Role</term>
<listitem>
<para>A personality that a user assumes that enables
them to perform a specific set of operations. A
role includes a set of rights and privileges. A
user assuming that role inherits those rights and
privileges.</para>
<para>In the Identity Service, a token that is issued
to a user includes the list of roles that user can
assume. Services that are being called by that
user determine how they interpret the set of roles
a user has and which operations or resources each
role grants access to.</para>
</listitem>
</varlistentry>
</variablelist>
<para>
<mediaobject>
<imageobject role="fo">
<imagedata
fileref="figures/SCH_5002_V00_NUAC-Keystone.png"
format="PNG" scale="50"/>
</imageobject>
<imageobject role="html">
<imagedata
fileref="figures/SCH_5002_V00_NUAC-Keystone.png"
format="PNG" scale="10"/>
</imageobject>
</mediaobject>
</para>
<section xml:id="keystone-user-management">
<title>User management</title>
<para>The main components of Identity user management are: <itemizedlist>
<listitem>
<para>Users</para>
</listitem>
<listitem>
<para>Tenants</para>
</listitem>
<listitem>
<para>Roles</para>
</listitem>
</itemizedlist></para>
<para>A <emphasis>user</emphasis> represents a human user, and
has associated information such as username, password and
email. This example creates a user named "alice":</para>
<screen><prompt>$</prompt> <userinput>keystone user-create --name=alice --pass=mypassword123 --email=alice@example.com</userinput></screen>
<para>A <emphasis>tenant</emphasis> can be a project, group,
or organization. Whenever you make requests to OpenStack
services, you must specify a tenant. For example, if you
query the Compute service for a list of running instances,
you will receive a list of all of the running instances in
the tenant you specified in your query. This example
creates a tenant named "acme":</para>
<screen><prompt>$</prompt> <userinput>keystone tenant-create --name=acme</userinput></screen>
<note>
<para>Because the term <emphasis>project</emphasis> was
used instead of <emphasis>tenant</emphasis> in earlier
versions of OpenStack Compute, some command-line tools
use <literal>--project_id</literal> instead of
<literal>--tenant-id</literal> or
<literal>--os-tenant-id</literal> to refer to a
tenant ID.</para>
</note>
<para>A <emphasis>role</emphasis> captures what operations a
user is permitted to perform in a given tenant. This
example creates a role named "compute-user":</para>
<screen><prompt>$</prompt> <userinput>keystone role-create --name=compute-user</userinput></screen>
<note>
<para>It is up to individual services such as the Compute
service and Image service to assign meaning to these
roles. As far as the Identity service is concerned, a
role is simply a name.</para>
</note>
<para>The Identity service associates a user with a tenant and
a role. To continue with our previous examples, we may
wish to assign the "alice" user the "compute-user" role in
the "acme" tenant:</para>
<screen><prompt>$</prompt> <userinput>keystone user-list</userinput></screen>
<screen><computeroutput>+--------+---------+-------------------+--------+
| id | enabled | email | name |
+--------+---------+-------------------+--------+
| 892585 | True | alice@example.com | alice |
+--------+---------+-------------------+--------+</computeroutput></screen>
<screen><prompt>$</prompt> <userinput>keystone role-list</userinput></screen>
<screen><computeroutput>+--------+--------------+
| id | name |
+--------+--------------+
| 9a764e | compute-user |
+--------+--------------+</computeroutput></screen>
<screen><prompt>$</prompt> <userinput>keystone tenant-list</userinput></screen>
<screen><computeroutput>+--------+------+---------+
| id | name | enabled |
+--------+------+---------+
| 6b8fd2 | acme | True |
+--------+------+---------+</computeroutput></screen>
<screen><prompt>$</prompt> <userinput>keystone user-role-add --user=892585 --role=9a764e --tenant-id=6b8fd2</userinput> </screen>
<para>A user can be assigned different roles in different
tenants: for example, Alice may also have the "admin" role
in the "Cyberdyne" tenant. A user can also be assigned
multiple roles in the same tenant.</para>
<para>The
<filename>/etc/<replaceable>[SERVICE_CODENAME]</replaceable>/policy.json</filename>
file controls what users are allowed to do for a given service.
For example, <filename>/etc/nova/policy.json</filename>
specifies the access policy for the Compute service,
<filename>/etc/glance/policy.json</filename> specifies
the access policy for the Image service, and
<filename>/etc/keystone/policy.json</filename>
specifies the access policy for the Identity service.</para>
<para>The default <filename>policy.json</filename> files in
the Compute, Identity, and Image service recognize only
the <literal>admin</literal> role: all operations that do
not require the <literal>admin</literal> role will be
accessible by any user that has any role in a tenant.</para>
<para>If you wish to restrict users from performing operations
in, say, the Compute service, you need to create a role in
the Identity service and then modify
<filename>/etc/nova/policy.json</filename> so that
this role is required for Compute operations.</para>
<para>For example, this line in
<filename>/etc/nova/policy.json</filename> specifies
that there are no restrictions on which users can create
volumes: if the user has any role in a tenant, they will
be able to create volumes in that tenant.</para>
<programlisting language="json">"volume:create": [],</programlisting>
<para>If we wished to restrict creation of volumes to users
who had the <literal>compute-user</literal> role in a
particular tenant, we would add
<literal>"role:compute-user"</literal>, like so:</para>
<programlisting language="json">"volume:create": ["role:compute-user"],</programlisting>
<para>
If we wished to restrict all Compute service requests to require
this role, the resulting file would look like:
</para>
<programlisting language="json">{
"admin_or_owner": [["role:admin"], ["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"],
"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_api"]],
"compute_extension:admin_actions:unlock": [["rule:admin_api"]],
"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"]
}</programlisting>
</section>
<section xml:id="keystone-service-mgmt">
<title>Service management</title>
<para>The Identity Service provides the following service
management functions:</para>
<itemizedlist>
<listitem>
<para>Services</para>
</listitem>
<listitem>
<para>Endpoints</para>
</listitem>
</itemizedlist>
<para>The Identity Service also maintains a user that
corresponds to each service (such as, a user named
<emphasis>nova</emphasis>, for the Compute service)
and a special service tenant, which is called
<emphasis>service</emphasis>.</para>
<para>The commands for creating services and endpoints are
described in a later section.</para>
</section>
</section>