Using Keystone with the Ceph Object Gateway Guide

Red Hat Ceph Storage 4

Configuring OpenStack and the Ceph Object Gateway to use Keystone for user authentication.

Red Hat Ceph Storage Documentation Team

Abstract

This document describes how to configure OpenStack and the Ceph Object Gateway to use Keystone for user authentication.
Red Hat is committed to replacing problematic language in our code, documentation, and web properties. We are beginning with these four terms: master, slave, blacklist, and whitelist. Because of the enormity of this endeavor, these changes will be implemented gradually over several upcoming releases. For more details, see our CTO Chris Wright's message.

Chapter 1. Keystone authentication and the Ceph Object Gateway

Organizations using OpenStack Keystone to authenticate users can integrate Keystone with the Ceph Object Gateway. The Ceph Object Gateway enables the gateway to accept a Keystone token, authenticate the user and create a corresponding Ceph Object Gateway user. When Keystone validates a token, the gateway considers the user authenticated.

Benefits

  • Managing users with Keystone
  • Automatic User Creation in the Ceph Object Gateway
  • The Ceph Object Gateway will query Keystone periodically for a list of revoked tokens.

Chapter 2. Configuring OpenStack’s Keystone for the Ceph Object Gateway

As a storage administrator, you can use OpenStack’s Keystone authentication service to authenticate users through the Ceph Object Gateway. Before you can configure the Ceph Object Gateway, you must configure Keystone which will enable the Swift service and point to the Ceph Object Gateway.

2.1. Prerequisites

  • A running Red Hat OpenStack Platform environment.
  • A running Red Hat Ceph Storage environment.
  • A running Ceph Object Gateway environment.

2.2. Creating the Swift service

Before configuring the Ceph Object Gateway, configure Keystone so that the Swift service is enabled and pointing to the Ceph Object Gateway.

Prerequisites

  • A running Red Hat Ceph Storage cluster.
  • Access to the Ceph software repository.
  • Root-level access to OpenStack controller node.

Procedure

  1. Create the Swift service:

    [root@swift~]# openstack service create --name=swift --description="Swift Service" object-store

    Creating the service will echo the service settings.

    Table 2.1. Example

    FieldValue

    description

    Swift Service

    enabled

    True

    id

    37c4c0e79571404cb4644201a4a6e5ee

    name

    swift

    type

    object-store

2.3. Setting the Ceph Object Gateway endpoints

After creating the Swift service, point the service to a Ceph Object Gateway.

Prerequisites

  • A running Red Hat Ceph Storage cluster.
  • Access to the Ceph software repository.
  • A running Swift service on a Red Hat OpenStack Platform 13, 15, or 16 environment.

Procedure

  1. Create the OpenStack endpoints pointing to the Ceph Object Gateway:

    Syntax

    openstack endpoint create --region REGION_NAME swift admin "URL"
    openstack endpoint create --region REGION_NAME swift public "URL"
    openstack endpoint create --region REGION_NAME swift internal "URL"

    Replace REGION_NAME with the name of the gateway’s zone group name or region name. Replace URL with URLs appropriate for the Ceph Object Gateway.

    Example

    [root@osp ~]# openstack endpoint create --region us-west swift admin "http://radosgw.example.com:8080/swift/v1"
    [root@osp ~]# openstack endpoint create --region us-west swift public "http://radosgw.example.com:8080/swift/v1"
    [root@osp ~]# openstack endpoint create --region us-west swift internal "http://radosgw.example.com:8080/swift/v1"

    FieldValue

    adminurl

    http://radosgw.example.com:8080/swift/v1

    id

    e4249d2b60e44743a67b5e5b38c18dd3

    internalurl

    http://radosgw.example.com:8080/swift/v1

    publicurl

    http://radosgw.example.com:8080/swift/v1

    region

    us-west

    service_id

    37c4c0e79571404cb4644201a4a6e5ee

    service_name

    swift

    service_type

    object-store

    Setting the endpoints will output the service endpoint settings.

2.4. Verifying Openstack is using the Ceph Object Gateway endpoints

After creating the Swift service and setting the endpoints, show the endpoints to ensure that all settings are correct.

Prerequisites

  • A running Red Hat Ceph Storage cluster.
  • Access to the Ceph software repository.

Procedure

  1. Verify settings in the configuration file:
[root@swift~]# openstack endpoint show object-store

Showing the endpoints will echo the endpoints settings, and the service settings.

Table 2.2. Example

FieldValue

adminurl

http://radosgw.example.com:8080/swift/v1

enabled

True

id

e4249d2b60e44743a67b5e5b38c18dd3

internalurl

http://radosgw.example.com:8080/swift/v1

publicurl

http://radosgw.example.com:8080/swift/v1

region

us-west

service_id

37c4c0e79571404cb4644201a4a6e5ee

service_name

swift

service_type

object-store

Chapter 3. Configuring the Ceph Object Gateway

As a storage administrator, you must configure the Ceph Object Gateway to accept authentication requests from the Keystone service.

3.1. Prerequisites

  • A running Red Hat OpenStack Platform environment.
  • A running Red Hat Ceph Storage environment.
  • A running Ceph Object Gateway environment.

3.2. Configuring the Ceph Object Gateway to use Keystone SSL

Converting the OpenSSL certificates that Keystone uses configures the Ceph Object Gateway to work with Keystone. When the Ceph Object Gateway interacts with OpenStack’s Keystone authentication, Keystone will terminate with a self-signed SSL certificate.

Prerequisites

  • A running Red Hat Ceph Storage cluster.
  • Access to the Ceph software repository.

Procedure

  1. Convert the OpenSSL certificate to the nss db format:

    Example

    [root@osp ~]# mkdir /var/ceph/nss
    
    [root@osp ~]# mkdir /var/ceph/nss openssl x509 -in /etc/keystone/ssl/certs/ca.pem -pubkey | \
        certutil -d /var/ceph/nss -A -n ca -t "TCu,Cu,Tuw"
    [root@osp ~]# mkdir /var/ceph/nss openssl x509 -in /etc/keystone/ssl/certs/signing_cert.pem -pubkey | \
        certutil -A -d /var/ceph/nss -n signing_cert -t "P,P,P"

  2. Install Keystone’s SSL certificate in the node running the Ceph Object Gateway. Alternatively set the value of the configurable rgw_keystone_verify_ssl setting to false.

    Setting rgw_keystone_verify_ssl to false means that the gateway won’t attempt to verify the certificate.

3.3. Configuring the Ceph Object Gateway to use Keystone authentication

Configure the Red Hat Ceph Storage to use OpenStack’s Keystone authentication.

Prerequisites

  • A running Red Hat Ceph Storage cluster.
  • Access to the Ceph software repository.
  • admin privileges to the production environment.

Procedure

  1. Edit the Ceph configuration file on the admin node.
  2. Navigate to the [client.radosgw.INSTANCE_NAME], where INSTANCE_NAME is the name of the Gateway instance to configure.
  3. Do the following for each gateway instance:

    1. Set the rgw_s3_auth_use_keystone setting to true.
    2. Set the nss_db_path setting to the path where the NSS database is stored.
  4. Provide authentication credentials:

    It is possible to configure a Keystone service tenant, user and password for keystone for v2.0 version of the OpenStack Identity API, similar to the way system administrators tend to configure OpenStack services. Providing a username and password avoids providing the shared secret to the rgw_keystone_admin_token setting.

    Important

    Red Hat recommends disabling authentication by admin token in production environments. The service tenant credentials should have admin privileges.

    The necessary configuration options are:

    rgw_keystone_admin_user = KEYSTONE_TENANT_USER_NAME
    rgw_keystone_admin_password = KEYSTONE_TENANT_USER_PASSWORD
    rgw_keystone_admin_tenant = KEYSTONE_TENANT_NAME

    A Ceph Object Gateway user is mapped into a Keystone tenant. A Keystone user has different roles assigned to it on possibly more than a single tenant. When the Ceph Object Gateway gets the ticket, it looks at the tenant, and the user roles that are assigned to that ticket, and accepts or rejects the request according to the rgw_keystone_accepted_roles configurable.

    A typical configuration might have the following settings:

    Example

    [client.radosgw.gateway]
    rgw_keystone_url = {keystone server url:keystone server admin port}
    ##Authentication using an admin token. Not preferred.
    #rgw_keystone_admin_token = {keystone admin token}
    ##Authentication using username, password and tenant. Preferred.
    rgw_keystone_admin_user = _KEYSTONE_TENANT_USER_NAME_
    rgw_keystone_admin_password =  _KEYSTONE_TENANT_USER_PASSWORD_
    rgw_keystone_admin_tenant =  _KEYSTONE_TENANT_NAME_
    rgw_keystone_accepted_roles = _KEYSTONE_ACCEPTED_USER_ROLES_
    ##
    rgw_keystone_token_cache_size = _NUMBER_OF_TOKENS_TO_CACHE_
    rgw_keystone_revocation_interval = _NUMBER_OF_SECONDS_BEFORE_CHECKING_REVOKED_TICKETS_
    rgw_keystone_make_new_tenants = _TRUE_FOR_PRIVATE_TENANT_FOR_EACH_NEW_USER_
    rgw_s3_auth_use_keystone = true
    nss_db_path = _PATH_TO_NSS_DB_

Additional Resources

3.4. Restarting the Ceph Object Gateway daemon

Restarting the Ceph Object Gateway must be done to active configuration changes.

Prerequisites

  • A running Red Hat Ceph Storage cluster.
  • Access to the Ceph software repository.
  • admin privileges to the production environment.

Procedure

  1. Once you have saved the Ceph configuration file and distributed it to each Ceph node, restart the Ceph Object Gateway instances:
[root@ceph~]# systemctl restart ceph-radosgw
[root@ceph~]# systemctl restart ceph-radosgw@rgw.`hostname -s`

Appendix A. Keystone integration configuration options

You can integrate your configuration options into Keystone. See below for a detailed description of the available Keystone integration configuration options:

Important

After updating the Ceph configuration file, you must copy the new Ceph configuration file to all Ceph nodes in the storage cluster.

rgw_s3_auth_use_keystone

Description
If set to true, the Ceph Object Gateway will authenticate users using Keystone.
Type
Boolean
Default
false

nss_db_path

Description
The path to the NSS database.
Type
String
Default
""

rgw_keystone_url

Description
The URL for the administrative RESTful API on the Keystone server.
Type
String
Default
""

rgw_keystone_admin_token

Description
The token or shared secret that is configured internally in Keystone for administrative requests.
Type
String
Default
""

rgw_keystone_admin_user

Description
The keystone admin user name.
Type
String
Default
""

rgw_keystone_admin_password

Description
The keystone admin user password.
Type
String
Default
""

rgw_keystone_admin_tenant

Description
The Keystone admin user tenant for keystone v2.0.
Type
String
Default
""

rgw_keystone_admin_project

Description
The Keystone admin user project for keystone v3.
Type
String
Default
""

rgw_keystone_admin_domain

Description
The Keystone admin user domain.
Type
String
Default
""

rgw_keystone_api_version

Description
The version of the Keystone API to use. Valid options are 2 or 3.
Type
Integer
Default
2

rgw_keystone_accepted_roles

Description
The roles required to serve requests.
Type
String
Default
"Member, admin"

rgw_keystone_accepted_admin_roles

Description
The list of roles allowing a user to gain administrative privileges.
Type
String
Default
""

rgw_keystone_token_cache_size

Description
The maximum number of entries in the Keystone token cache.
Type
Integer
Default
10000

rgw_keystone_revocation_interval

Description
The number seconds between tokens revocation check.
Type
Integer
Default
15 * 60

rgw_keystone_verify_ssl

Description
If true Ceph will try to verify Keystone’s SSL certificate.
Type
Boolean
Default
true

rgw_keystone_implicit_tenants

Description
Create new users in their own tenants of the same name. Set this to true or false under most circumstances. For compatibility with previous versions of Red Hat Ceph Storage, it is also possible to set this to s3 or swift. This has the effect of splitting the identity space such that only the indicated protocol will use implicit tenants. Some older versions of Red Hat Ceph Storage only supported implicit tenants with Swift.
Type
String
Default
false

Legal Notice

Copyright © 2021 Red Hat, Inc.
The text of and illustrations in this document are licensed by Red Hat under a Creative Commons Attribution–Share Alike 3.0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available at http://creativecommons.org/licenses/by-sa/3.0/. In accordance with CC-BY-SA, if you distribute this document or an adaptation of it, you must provide the URL for the original version.
Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert, Section 4d of CC-BY-SA to the fullest extent permitted by applicable law.
Red Hat, Red Hat Enterprise Linux, the Shadowman logo, the Red Hat logo, JBoss, OpenShift, Fedora, the Infinity logo, and RHCE are trademarks of Red Hat, Inc., registered in the United States and other countries.
Linux® is the registered trademark of Linus Torvalds in the United States and other countries.
Java® is a registered trademark of Oracle and/or its affiliates.
XFS® is a trademark of Silicon Graphics International Corp. or its subsidiaries in the United States and/or other countries.
MySQL® is a registered trademark of MySQL AB in the United States, the European Union and other countries.
Node.js® is an official trademark of Joyent. Red Hat is not formally related to or endorsed by the official Joyent Node.js open source or commercial project.
The OpenStack® Word Mark and OpenStack logo are either registered trademarks/service marks or trademarks/service marks of the OpenStack Foundation, in the United States and other countries and are used with the OpenStack Foundation's permission. We are not affiliated with, endorsed or sponsored by the OpenStack Foundation, or the OpenStack community.
All other trademarks are the property of their respective owners.