Chapter 2. Configuring the Ceph Object Gateway

Configuring the Ceph Object Gateway to work with Keystone requires converting the OpenSSL certificates that Keystone uses for creating the requests to the nss db format, for example:

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"
openssl x509 -in /etc/keystone/ssl/certs/signing_cert.pem -pubkey | \
    certutil -A -d /var/ceph/nss -n signing_cert -t "P,P,P"

Openstack Keystone may also be terminated with a self-signed SSL certificate, in order for the Ceph Object Gateway to interact with Keystone. Either install Keystone’s SSL certificate in the node running the Ceph Object Gateway, or 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.

To configure the Ceph Object Gateway to use Keystone, open the Ceph configuration file on the admin node and navigate to the [client.radosgw.{instance-name}], where {instance-name} is the name of the Gateway instance to configure. For each gateway instance, set the rgw_s3_auth_use_keystone setting to true, and set the nss_db_path setting to the path where the NSS database is stored.

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. Red Hat recommends disabling authentication by admin token in production environments.

The service tenant credentials should have admin privileges. For more details see the Users and Identity Management Guide for Red Hat OpenStack Platform 13. The requisite configuration options for are:

rgw_keystone_admin_user = {keystone service tenant user name}
rgw_keystone_admin_password = {keystone service tenant user password}
rgw_keystone_admin_tenant = {keystone service 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/rejects the request according to the rgw_keystone_accepted_roles configurable.

A typical configuration might have the following settings:

[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 service tenant user name}
rgw_keystone_admin_password = {keystone service tenant user password}
rgw_keystone_admin_tenant = {keystone service tenant name}
rgw_keystone_accepted_roles = {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}

Save the changes to the Ceph configuration file. Then, copy the updated Ceph configuration file to each Ceph node. For example:

# scp /etc/ceph/ceph.conf <node-name>:/etc/ceph/

See below for a detailed description of the available Keystone integration configuration options:

Once you have saved the Ceph configuration file and distributed it to each Ceph node, restart the Ceph Object Gateway instances. Usage should be one of:

# systemctl restart ceph-radosgw
# systemctl restart ceph-radosgw@rgw.`hostname -s`