Cephx Config Reference¶

The cephx protocol is enabled by default. Cryptographic authentication has some computational costs, though they should generally be quite low. If the network environment connecting your client and server hosts is very safe and you cannot afford authentication, you can turn it off. This is not generally recommended.

Note

If you disable authentication, you are at risk of a man-in-the-middle attack altering your client/server messages, which could lead to disastrous security effects.

For creating users, see User Management. For details on the architecture of Cephx, see Architecture - High Availability Authentication.

Deployment Scenarios¶

There are two main scenarios for deploying a Ceph cluster, which impact how you initially configure Cephx. Most first time Ceph users use ceph-deploy to create a cluster (easiest). For clusters using other deployment tools (e.g., Chef, Juju, Puppet, etc.), you will need to use the manual procedures or configure your deployment tool to bootstrap your monitor(s).

ceph-deploy¶

When you deploy a cluster with ceph-deploy, you do not have to bootstrap the monitor manually or create the client.admin user or keyring. The steps you execute in the Storage Cluster Quick Start will invoke ceph-deploy to do that for you.

When you execute ceph-deploy new {initial-monitor(s)}, Ceph will create a monitor keyring for you (only used to bootstrap monitors), and it will generate an initial Ceph configuration file for you, which contains the following authentication settings, indicating that Ceph enables authentication by default:

auth_cluster_required = cephx
auth_service_required = cephx
auth_client_required = cephx

When you execute ceph-deploy mon create-initial, Ceph will bootstrap the initial monitor(s), retrieve a ceph.client.admin.keyring file containing the key for the client.admin user. Additionally, it will also retrieve keyrings that give ceph-deploy and ceph-volume utilities the ability to prepare and activate OSDs and metadata servers.

When you execute ceph-deploy admin {node-name} (note: Ceph must be installed first), you are pushing a Ceph configuration file and the ceph.client.admin.keyring to the /etc/ceph directory of the node. You will be able to execute Ceph administrative functions as root on the command line of that node.

Manual Deployment¶

When you deploy a cluster manually, you have to bootstrap the monitor manually and create the client.admin user and keyring. To bootstrap monitors, follow the steps in Monitor Bootstrapping. The steps for monitor bootstrapping are the logical steps you must perform when using third party deployment tools like Chef, Puppet, Juju, etc.

Enabling/Disabling Cephx¶

Enabling Cephx requires that you have deployed keys for your monitors, OSDs and metadata servers. If you are simply toggling Cephx on / off, you do not have to repeat the bootstrapping procedures.

Enabling Cephx¶

When cephx is enabled, Ceph will look for the keyring in the default search path, which includes /etc/ceph/$cluster.$name.keyring. You can override this location by adding a keyring option in the [global] section of your Ceph configuration file, but this is not recommended.

Execute the following procedures to enable cephx on a cluster with authentication disabled. If you (or your deployment utility) have already generated the keys, you may skip the steps related to generating keys.

Create a client.admin key, and save a copy of the key for your client host:
```
ceph auth get-or-create client.admin mon 'allow *' mds 'allow *' mgr 'allow *' osd 'allow *' -o /etc/ceph/ceph.client.admin.keyring
```
Warning: This will clobber any existing /etc/ceph/client.admin.keyring file. Do not perform this step if a deployment tool has already done it for you. Be careful!

Create a keyring for your monitor cluster and generate a monitor secret key.

ceph-authtool --create-keyring /tmp/ceph.mon.keyring --gen-key -n mon. --cap mon 'allow *'

Copy the monitor keyring into a ceph.mon.keyring file in every monitor’s mon data directory. For example, to copy it to mon.a in cluster ceph, use the following:
```
cp /tmp/ceph.mon.keyring /var/lib/ceph/mon/ceph-a/keyring
```

Generate a secret key for every MGR, where {$id} is the MGR letter:

ceph auth get-or-create mgr.{$id} mon 'allow profile mgr' mds 'allow *' osd 'allow *' -o /var/lib/ceph/mgr/ceph-{$id}/keyring

Generate a secret key for every OSD, where {$id} is the OSD number:

ceph auth get-or-create osd.{$id} mon 'allow rwx' osd 'allow *' -o /var/lib/ceph/osd/ceph-{$id}/keyring

Generate a secret key for every MDS, where {$id} is the MDS letter:

ceph auth get-or-create mds.{$id} mon 'allow rwx' osd 'allow *' mds 'allow *' mgr 'allow profile mds' -o /var/lib/ceph/mds/ceph-{$id}/keyring

Enable cephx authentication by setting the following options in the [global] section of your Ceph configuration file:
```
auth cluster required = cephx
auth service required = cephx
auth client required = cephx
```
Start or restart the Ceph cluster. See Operating a Cluster for details.

For details on bootstrapping a monitor manually, see Manual Deployment.

Disabling Cephx¶

The following procedure describes how to disable Cephx. If your cluster environment is relatively safe, you can offset the computation expense of running authentication. We do not recommend it. However, it may be easier during setup and/or troubleshooting to temporarily disable authentication.

Disable cephx authentication by setting the following options in the [global] section of your Ceph configuration file:
```
auth cluster required = none
auth service required = none
auth client required = none
```
Start or restart the Ceph cluster. See Operating a Cluster for details.

Configuration Settings¶

Enablement¶

auth cluster required

Description: If enabled, the Ceph Storage Cluster daemons (i.e., ceph-mon, ceph-osd, ceph-mds and ceph-mgr) must authenticate with each other. Valid settings are cephx or none.
Type: String
Required: No
Default: cephx.

auth service required

Description: If enabled, the Ceph Storage Cluster daemons require Ceph Clients to authenticate with the Ceph Storage Cluster in order to access Ceph services. Valid settings are cephx or none.
Type: String
Required: No
Default: cephx.

auth client required

Description: If enabled, the Ceph Client requires the Ceph Storage Cluster to authenticate with the Ceph Client. Valid settings are cephx or none.
Type: String
Required: No
Default: cephx.

Keys¶

When you run Ceph with authentication enabled, ceph administrative commands and Ceph Clients require authentication keys to access the Ceph Storage Cluster.

The most common way to provide these keys to the ceph administrative commands and clients is to include a Ceph keyring under the /etc/ceph directory. For Cuttlefish and later releases using ceph-deploy, the filename is usually ceph.client.admin.keyring (or $cluster.client.admin.keyring). If you include the keyring under the /etc/ceph directory, you don’t need to specify a keyring entry in your Ceph configuration file.

We recommend copying the Ceph Storage Cluster’s keyring file to nodes where you will run administrative commands, because it contains the client.admin key.

You may use ceph-deploy admin to perform this task. See Create an Admin Host for details. To perform this step manually, execute the following:

sudo scp {user}@{ceph-cluster-host}:/etc/ceph/ceph.client.admin.keyring /etc/ceph/ceph.client.admin.keyring

Tip

Ensure the ceph.keyring file has appropriate permissions set (e.g., chmod 644) on your client machine.

You may specify the key itself in the Ceph configuration file using the key setting (not recommended), or a path to a keyfile using the keyfile setting.

keyring

Description: The path to the keyring file.
Type: String
Required: No
Default: /etc/ceph/$cluster.$name.keyring,/etc/ceph/$cluster.keyring,/etc/ceph/keyring,/etc/ceph/keyring.bin

keyfile

Description: The path to a key file (i.e,. a file containing only the key).
Type: String
Required: No
Default: None

key

Description: The key (i.e., the text string of the key itself). Not recommended.
Type: String
Required: No
Default: None

Daemon Keyrings¶

Administrative users or deployment tools (e.g., ceph-deploy) may generate daemon keyrings in the same way as generating user keyrings. By default, Ceph stores daemons keyrings inside their data directory. The default keyring locations, and the capabilities necessary for the daemon to function, are shown below.

ceph-mon

Location: $mon_data/keyring
Capabilities: mon 'allow *'

ceph-osd

Location: $osd_data/keyring
Capabilities: mgr 'allow profile osd' mon 'allow profile osd' osd 'allow *'

ceph-mds

Location: $mds_data/keyring
Capabilities: mds 'allow' mgr 'allow profile mds' mon 'allow profile mds' osd 'allow rwx'

ceph-mgr

Location: $mgr_data/keyring
Capabilities: mon 'allow profile mgr' mds 'allow *' osd 'allow *'

radosgw

Location: $rgw_data/keyring
Capabilities: mon 'allow rwx' osd 'allow rwx'

Note

The monitor keyring (i.e., mon.) contains a key but no capabilities, and is not part of the cluster auth database.

The daemon data directory locations default to directories of the form:

/var/lib/ceph/$type/$cluster-$id

For example, osd.12 would be:

/var/lib/ceph/osd/ceph-12

You can override these locations, but it is not recommended.

Signatures¶

Ceph performs a signature check that provides some limited protection against messages being tampered with in flight (e.g., by a “man in the middle” attack).

Like other parts of Ceph authentication, Ceph provides fine-grained control so you can enable/disable signatures for service messages between the client and Ceph, and you can enable/disable signatures for messages between Ceph daemons.

Note that even with signatures enabled data is not encrypted in flight.

cephx require signatures

Description

If set to true, Ceph requires signatures on all message traffic between the Ceph Client and the Ceph Storage Cluster, and between daemons comprising the Ceph Storage Cluster.

Ceph Argonaut and Linux kernel versions prior to 3.19 do not support signatures; if such clients are in use this option can be turned off to allow them to connect.

Type

Boolean

Required

No

Default

false

cephx cluster require signatures

Description: If set to true, Ceph requires signatures on all message traffic between Ceph daemons comprising the Ceph Storage Cluster.
Type: Boolean
Required: No
Default: false

cephx service require signatures

Description: If set to true, Ceph requires signatures on all message traffic between Ceph Clients and the Ceph Storage Cluster.
Type: Boolean
Required: No
Default: false

cephx sign messages

Description: If the Ceph version supports message signing, Ceph will sign all messages so they are more difficult to spoof.
Type: Boolean
Default: true

Time to Live¶

auth service ticket ttl

Description: When the Ceph Storage Cluster sends a Ceph Client a ticket for authentication, the Ceph Storage Cluster assigns the ticket a time to live.
Type: Double
Default: 60*60