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diff --git a/doc/rados/operations/user-management.rst b/doc/rados/operations/user-management.rst new file mode 100644 index 000000000..130c02002 --- /dev/null +++ b/doc/rados/operations/user-management.rst @@ -0,0 +1,840 @@ +.. _user-management: + +================= + User Management +================= + +This document describes :term:`Ceph Client` users, and describes the process by +which they perform authentication and authorization so that they can access the +:term:`Ceph Storage Cluster`. Users are either individuals or system actors +(for example, applications) that use Ceph clients to interact with the Ceph +Storage Cluster daemons. + +.. ditaa:: + +-----+ + | {o} | + | | + +--+--+ /---------\ /---------\ + | | Ceph | | Ceph | + ---+---*----->| |<------------->| | + | uses | Clients | | Servers | + | \---------/ \---------/ + /--+--\ + | | + | | + actor + + +When Ceph runs with authentication and authorization enabled (both are enabled +by default), you must specify a user name and a keyring that contains the +secret key of the specified user (usually these are specified via the command +line). If you do not specify a user name, Ceph will use ``client.admin`` as the +default user name. If you do not specify a keyring, Ceph will look for a +keyring via the ``keyring`` setting in the Ceph configuration. For example, if +you execute the ``ceph health`` command without specifying a user or a keyring, +Ceph will assume that the keyring is in ``/etc/ceph/ceph.client.admin.keyring`` +and will attempt to use that keyring. The following illustrates this behavior: + +.. prompt:: bash $ + + ceph health + +Ceph will interpret the command like this: + +.. prompt:: bash $ + + ceph -n client.admin --keyring=/etc/ceph/ceph.client.admin.keyring health + +Alternatively, you may use the ``CEPH_ARGS`` environment variable to avoid +re-entry of the user name and secret. + +For details on configuring the Ceph Storage Cluster to use authentication, see +`Cephx Config Reference`_. For details on the architecture of Cephx, see +`Architecture - High Availability Authentication`_. + +Background +========== + +No matter what type of Ceph client is used (for example: Block Device, Object +Storage, Filesystem, native API), Ceph stores all data as RADOS objects within +`pools`_. Ceph users must have access to a given pool in order to read and +write data, and Ceph users must have execute permissions in order to use Ceph's +administrative commands. The following concepts will help you understand +Ceph['s] user management. + +.. _rados-ops-user: + +User +---- + +A user is either an individual or a system actor (for example, an application). +Creating users allows you to control who (or what) can access your Ceph Storage +Cluster, its pools, and the data within those pools. + +Ceph has the concept of a ``type`` of user. For purposes of user management, +the type will always be ``client``. Ceph identifies users in a "period- +delimited form" that consists of the user type and the user ID: for example, +``TYPE.ID``, ``client.admin``, or ``client.user1``. The reason for user typing +is that the Cephx protocol is used not only by clients but also non-clients, +such as Ceph Monitors, OSDs, and Metadata Servers. Distinguishing the user type +helps to distinguish between client users and other users. This distinction +streamlines access control, user monitoring, and traceability. + +Sometimes Ceph's user type might seem confusing, because the Ceph command line +allows you to specify a user with or without the type, depending upon your +command line usage. If you specify ``--user`` or ``--id``, you can omit the +type. For example, ``client.user1`` can be entered simply as ``user1``. On the +other hand, if you specify ``--name`` or ``-n``, you must supply the type and +name: for example, ``client.user1``. We recommend using the type and name as a +best practice wherever possible. + +.. note:: A Ceph Storage Cluster user is not the same as a Ceph Object Storage + user or a Ceph File System user. The Ceph Object Gateway uses a Ceph Storage + Cluster user to communicate between the gateway daemon and the storage + cluster, but the Ceph Object Gateway has its own user-management + functionality for end users. The Ceph File System uses POSIX semantics, and + the user space associated with the Ceph File System is not the same as the + user space associated with a Ceph Storage Cluster user. + +Authorization (Capabilities) +---------------------------- + +Ceph uses the term "capabilities" (caps) to describe the permissions granted to +an authenticated user to exercise the functionality of the monitors, OSDs, and +metadata servers. Capabilities can also restrict access to data within a pool, +a namespace within a pool, or a set of pools based on their application tags. +A Ceph administrative user specifies the capabilities of a user when creating +or updating that user. + +Capability syntax follows this form:: + + {daemon-type} '{cap-spec}[, {cap-spec} ...]' + +- **Monitor Caps:** Monitor capabilities include ``r``, ``w``, ``x`` access + settings, and can be applied in aggregate from pre-defined profiles with + ``profile {name}``. For example:: + + mon 'allow {access-spec} [network {network/prefix}]' + + mon 'profile {name}' + + The ``{access-spec}`` syntax is as follows: :: + + * | all | [r][w][x] + + The optional ``{network/prefix}`` is a standard network name and prefix + length in CIDR notation (for example, ``10.3.0.0/16``). If + ``{network/prefix}`` is present, the monitor capability can be used only by + clients that connect from the specified network. + +- **OSD Caps:** OSD capabilities include ``r``, ``w``, ``x``, and + ``class-read`` and ``class-write`` access settings. OSD capabilities can be + applied in aggregate from pre-defined profiles with ``profile {name}``. In + addition, OSD capabilities allow for pool and namespace settings. :: + + osd 'allow {access-spec} [{match-spec}] [network {network/prefix}]' + + osd 'profile {name} [pool={pool-name} [namespace={namespace-name}]] [network {network/prefix}]' + + There are two alternative forms of the ``{access-spec}`` syntax: :: + + * | all | [r][w][x] [class-read] [class-write] + + class {class name} [{method name}] + + There are two alternative forms of the optional ``{match-spec}`` syntax:: + + pool={pool-name} [namespace={namespace-name}] [object_prefix {prefix}] + + [namespace={namespace-name}] tag {application} {key}={value} + + The optional ``{network/prefix}`` is a standard network name and prefix + length in CIDR notation (for example, ``10.3.0.0/16``). If + ``{network/prefix}`` is present, the OSD capability can be used only by + clients that connect from the specified network. + +- **Manager Caps:** Manager (``ceph-mgr``) capabilities include ``r``, ``w``, + ``x`` access settings, and can be applied in aggregate from pre-defined + profiles with ``profile {name}``. For example:: + + mgr 'allow {access-spec} [network {network/prefix}]' + + mgr 'profile {name} [{key1} {match-type} {value1} ...] [network {network/prefix}]' + + Manager capabilities can also be specified for specific commands, for all + commands exported by a built-in manager service, or for all commands exported + by a specific add-on module. For example:: + + mgr 'allow command "{command-prefix}" [with {key1} {match-type} {value1} ...] [network {network/prefix}]' + + mgr 'allow service {service-name} {access-spec} [network {network/prefix}]' + + mgr 'allow module {module-name} [with {key1} {match-type} {value1} ...] {access-spec} [network {network/prefix}]' + + The ``{access-spec}`` syntax is as follows: :: + + * | all | [r][w][x] + + The ``{service-name}`` is one of the following: :: + + mgr | osd | pg | py + + The ``{match-type}`` is one of the following: :: + + = | prefix | regex + +- **Metadata Server Caps:** For administrators, use ``allow *``. For all other + users (for example, CephFS clients), consult :doc:`/cephfs/client-auth` + +.. note:: The Ceph Object Gateway daemon (``radosgw``) is a client of the + Ceph Storage Cluster. For this reason, it is not represented as + a Ceph Storage Cluster daemon type. + +The following entries describe access capabilities. + +``allow`` + +:Description: Precedes access settings for a daemon. Implies ``rw`` + for MDS only. + + +``r`` + +:Description: Gives the user read access. Required with monitors to retrieve + the CRUSH map. + + +``w`` + +:Description: Gives the user write access to objects. + + +``x`` + +:Description: Gives the user the capability to call class methods + (that is, both read and write) and to conduct ``auth`` + operations on monitors. + + +``class-read`` + +:Descriptions: Gives the user the capability to call class read methods. + Subset of ``x``. + + +``class-write`` + +:Description: Gives the user the capability to call class write methods. + Subset of ``x``. + + +``*``, ``all`` + +:Description: Gives the user read, write, and execute permissions for a + particular daemon/pool, as well as the ability to execute + admin commands. + + +The following entries describe valid capability profiles: + +``profile osd`` (Monitor only) + +:Description: Gives a user permissions to connect as an OSD to other OSDs or + monitors. Conferred on OSDs in order to enable OSDs to handle replication + heartbeat traffic and status reporting. + + +``profile mds`` (Monitor only) + +:Description: Gives a user permissions to connect as an MDS to other MDSs or + monitors. + + +``profile bootstrap-osd`` (Monitor only) + +:Description: Gives a user permissions to bootstrap an OSD. Conferred on + deployment tools such as ``ceph-volume`` and ``cephadm`` + so that they have permissions to add keys when + bootstrapping an OSD. + + +``profile bootstrap-mds`` (Monitor only) + +:Description: Gives a user permissions to bootstrap a metadata server. + Conferred on deployment tools such as ``cephadm`` + so that they have permissions to add keys when bootstrapping + a metadata server. + +``profile bootstrap-rbd`` (Monitor only) + +:Description: Gives a user permissions to bootstrap an RBD user. + Conferred on deployment tools such as ``cephadm`` + so that they have permissions to add keys when bootstrapping + an RBD user. + +``profile bootstrap-rbd-mirror`` (Monitor only) + +:Description: Gives a user permissions to bootstrap an ``rbd-mirror`` daemon + user. Conferred on deployment tools such as ``cephadm`` so that + they have permissions to add keys when bootstrapping an + ``rbd-mirror`` daemon. + +``profile rbd`` (Manager, Monitor, and OSD) + +:Description: Gives a user permissions to manipulate RBD images. When used as a + Monitor cap, it provides the user with the minimal privileges + required by an RBD client application; such privileges include + the ability to blocklist other client users. When used as an OSD + cap, it provides an RBD client application with read-write access + to the specified pool. The Manager cap supports optional ``pool`` + and ``namespace`` keyword arguments. + +``profile rbd-mirror`` (Monitor only) + +:Description: Gives a user permissions to manipulate RBD images and retrieve + RBD mirroring config-key secrets. It provides the minimal + privileges required for the user to manipulate the ``rbd-mirror`` + daemon. + +``profile rbd-read-only`` (Manager and OSD) + +:Description: Gives a user read-only permissions to RBD images. The Manager cap + supports optional ``pool`` and ``namespace`` keyword arguments. + +``profile simple-rados-client`` (Monitor only) + +:Description: Gives a user read-only permissions for monitor, OSD, and PG data. + Intended for use by direct librados client applications. + +``profile simple-rados-client-with-blocklist`` (Monitor only) + +:Description: Gives a user read-only permissions for monitor, OSD, and PG data. + Intended for use by direct librados client applications. Also + includes permissions to add blocklist entries to build + high-availability (HA) applications. + +``profile fs-client`` (Monitor only) + +:Description: Gives a user read-only permissions for monitor, OSD, PG, and MDS + data. Intended for CephFS clients. + +``profile role-definer`` (Monitor and Auth) + +:Description: Gives a user **all** permissions for the auth subsystem, read-only + access to monitors, and nothing else. Useful for automation + tools. Do not assign this unless you really, **really** know what + you're doing, as the security ramifications are substantial and + pervasive. + +``profile crash`` (Monitor and MGR) + +:Description: Gives a user read-only access to monitors. Used in conjunction + with the manager ``crash`` module to upload daemon crash + dumps into monitor storage for later analysis. + +Pool +---- + +A pool is a logical partition where users store data. +In Ceph deployments, it is common to create a pool as a logical partition for +similar types of data. For example, when deploying Ceph as a back end for +OpenStack, a typical deployment would have pools for volumes, images, backups +and virtual machines, and such users as ``client.glance`` and ``client.cinder``. + +Application Tags +---------------- + +Access may be restricted to specific pools as defined by their application +metadata. The ``*`` wildcard may be used for the ``key`` argument, the +``value`` argument, or both. The ``all`` tag is a synonym for ``*``. + +Namespace +--------- + +Objects within a pool can be associated to a namespace: that is, to a logical group of +objects within the pool. A user's access to a pool can be associated with a +namespace so that reads and writes by the user can take place only within the +namespace. Objects written to a namespace within the pool can be accessed only +by users who have access to the namespace. + +.. note:: Namespaces are primarily useful for applications written on top of + ``librados``. In such situations, the logical grouping provided by + namespaces can obviate the need to create different pools. In Luminous and + later releases, Ceph Object Gateway uses namespaces for various metadata + objects. + +The rationale for namespaces is this: namespaces are relatively less +computationally expensive than pools, which (pools) can be a computationally +expensive method of segregating data sets between different authorized users. + +For example, a pool ought to host approximately 100 placement-group replicas +per OSD. This means that a cluster with 1000 OSDs and three 3R replicated pools +would have (in a single pool) 100,000 placement-group replicas, and that means +that it has 33,333 Placement Groups. + +By contrast, writing an object to a namespace simply associates the namespace +to the object name without incurring the computational overhead of a separate +pool. Instead of creating a separate pool for a user or set of users, you can +use a namespace. + +.. note:: + + Namespaces are available only when using ``librados``. + + +Access may be restricted to specific RADOS namespaces by use of the ``namespace`` +capability. Limited globbing of namespaces (that is, use of wildcards (``*``)) is supported: if the last character +of the specified namespace is ``*``, then access is granted to any namespace +starting with the provided argument. + +Managing Users +============== + +User management functionality provides Ceph Storage Cluster administrators with +the ability to create, update, and delete users directly in the Ceph Storage +Cluster. + +When you create or delete users in the Ceph Storage Cluster, you might need to +distribute keys to clients so that they can be added to keyrings. For details, see `Keyring +Management`_. + +Listing Users +------------- + +To list the users in your cluster, run the following command: + +.. prompt:: bash $ + + ceph auth ls + +Ceph will list all users in your cluster. For example, in a two-node +cluster, ``ceph auth ls`` will provide an output that resembles the following:: + + installed auth entries: + + osd.0 + key: AQCvCbtToC6MDhAATtuT70Sl+DymPCfDSsyV4w== + caps: [mon] allow profile osd + caps: [osd] allow * + osd.1 + key: AQC4CbtTCFJBChAAVq5spj0ff4eHZICxIOVZeA== + caps: [mon] allow profile osd + caps: [osd] allow * + client.admin + key: AQBHCbtT6APDHhAA5W00cBchwkQjh3dkKsyPjw== + caps: [mds] allow + caps: [mon] allow * + caps: [osd] allow * + client.bootstrap-mds + key: AQBICbtTOK9uGBAAdbe5zcIGHZL3T/u2g6EBww== + caps: [mon] allow profile bootstrap-mds + client.bootstrap-osd + key: AQBHCbtT4GxqORAADE5u7RkpCN/oo4e5W0uBtw== + caps: [mon] allow profile bootstrap-osd + +Note that, according to the ``TYPE.ID`` notation for users, ``osd.0`` is a +user of type ``osd`` and an ID of ``0``, and ``client.admin`` is a user of type +``client`` and an ID of ``admin`` (that is, the default ``client.admin`` user). +Note too that each entry has a ``key: <value>`` entry, and also has one or more +``caps:`` entries. + +To save the output of ``ceph auth ls`` to a file, use the ``-o {filename}`` option. + + +Getting a User +-------------- + +To retrieve a specific user, key, and capabilities, run the following command: + +.. prompt:: bash $ + + ceph auth get {TYPE.ID} + +For example: + +.. prompt:: bash $ + + ceph auth get client.admin + +To save the output of ``ceph auth get`` to a file, use the ``-o {filename}`` option. Developers may also run the following command: + +.. prompt:: bash $ + + ceph auth export {TYPE.ID} + +The ``auth export`` command is identical to ``auth get``. + +.. _rados_ops_adding_a_user: + +Adding a User +------------- + +Adding a user creates a user name (that is, ``TYPE.ID``), a secret key, and +any capabilities specified in the command that creates the user. + +A user's key allows the user to authenticate with the Ceph Storage Cluster. +The user's capabilities authorize the user to read, write, or execute on Ceph +monitors (``mon``), Ceph OSDs (``osd``) or Ceph Metadata Servers (``mds``). + +There are a few ways to add a user: + +- ``ceph auth add``: This command is the canonical way to add a user. It + will create the user, generate a key, and add any specified capabilities. + +- ``ceph auth get-or-create``: This command is often the most convenient way + to create a user, because it returns a keyfile format with the user name + (in brackets) and the key. If the user already exists, this command + simply returns the user name and key in the keyfile format. To save the output to + a file, use the ``-o {filename}`` option. + +- ``ceph auth get-or-create-key``: This command is a convenient way to create + a user and return the user's key and nothing else. This is useful for clients that + need only the key (for example, libvirt). If the user already exists, this command + simply returns the key. To save the output to + a file, use the ``-o {filename}`` option. + +It is possible, when creating client users, to create a user with no capabilities. A user +with no capabilities is useless beyond mere authentication, because the client +cannot retrieve the cluster map from the monitor. However, you might want to create a user +with no capabilities and wait until later to add capabilities to the user by using the ``ceph auth caps`` comand. + +A typical user has at least read capabilities on the Ceph monitor and +read and write capabilities on Ceph OSDs. A user's OSD permissions +are often restricted so that the user can access only one particular pool. +In the following example, the commands (1) add a client named ``john`` that has read capabilities on the Ceph monitor +and read and write capabilities on the pool named ``liverpool``, (2) authorize a client named ``paul`` to have read capabilities on the Ceph monitor and +read and write capabilities on the pool named ``liverpool``, (3) authorize a client named ``george`` to have read capabilities on the Ceph monitor and +read and write capabilities on the pool named ``liverpool`` and use the keyring named ``george.keyring`` to make this authorization, and (4) authorize +a client named ``ringo`` to have read capabilities on the Ceph monitor and read and write capabilities on the pool named ``liverpool`` and use the key +named ``ringo.key`` to make this authorization: + +.. prompt:: bash $ + + ceph auth add client.john mon 'allow r' osd 'allow rw pool=liverpool' + ceph auth get-or-create client.paul mon 'allow r' osd 'allow rw pool=liverpool' + ceph auth get-or-create client.george mon 'allow r' osd 'allow rw pool=liverpool' -o george.keyring + ceph auth get-or-create-key client.ringo mon 'allow r' osd 'allow rw pool=liverpool' -o ringo.key + +.. important:: Any user that has capabilities on OSDs will have access to ALL pools in the cluster + unless that user's access has been restricted to a proper subset of the pools in the cluster. + + +.. _modify-user-capabilities: + +Modifying User Capabilities +--------------------------- + +The ``ceph auth caps`` command allows you to specify a user and change that +user's capabilities. Setting new capabilities will overwrite current capabilities. +To view current capabilities, run ``ceph auth get USERTYPE.USERID``. +To add capabilities, run a command of the following form (and be sure to specify the existing capabilities): + +.. prompt:: bash $ + + ceph auth caps USERTYPE.USERID {daemon} 'allow [r|w|x|*|...] [pool={pool-name}] [namespace={namespace-name}]' [{daemon} 'allow [r|w|x|*|...] [pool={pool-name}] [namespace={namespace-name}]'] + +For example: + +.. prompt:: bash $ + + ceph auth get client.john + ceph auth caps client.john mon 'allow r' osd 'allow rw pool=liverpool' + ceph auth caps client.paul mon 'allow rw' osd 'allow rwx pool=liverpool' + ceph auth caps client.brian-manager mon 'allow *' osd 'allow *' + +For additional details on capabilities, see `Authorization (Capabilities)`_. + +Deleting a User +--------------- + +To delete a user, use ``ceph auth del``: + +.. prompt:: bash $ + + ceph auth del {TYPE}.{ID} + +Here ``{TYPE}`` is either ``client``, ``osd``, ``mon``, or ``mds``, +and ``{ID}`` is the user name or the ID of the daemon. + + +Printing a User's Key +--------------------- + +To print a user's authentication key to standard output, run the following command: + +.. prompt:: bash $ + + ceph auth print-key {TYPE}.{ID} + +Here ``{TYPE}`` is either ``client``, ``osd``, ``mon``, or ``mds``, +and ``{ID}`` is the user name or the ID of the daemon. + +When it is necessary to populate client software with a user's key (as in the case of libvirt), +you can print the user's key by running the following command: + +.. prompt:: bash $ + + mount -t ceph serverhost:/ mountpoint -o name=client.user,secret=`ceph auth print-key client.user` + +Importing a User +---------------- + +To import one or more users, use ``ceph auth import`` and +specify a keyring as follows: + +.. prompt:: bash $ + + ceph auth import -i /path/to/keyring + +For example: + +.. prompt:: bash $ + + sudo ceph auth import -i /etc/ceph/ceph.keyring + +.. note:: The Ceph storage cluster will add new users, their keys, and their + capabilities and will update existing users, their keys, and their + capabilities. + +Keyring Management +================== + +When you access Ceph via a Ceph client, the Ceph client will look for a local +keyring. Ceph presets the ``keyring`` setting with four keyring +names by default. For this reason, you do not have to set the keyring names in your Ceph configuration file +unless you want to override these defaults (which is not recommended). The four default keyring names are as follows: + +- ``/etc/ceph/$cluster.$name.keyring`` +- ``/etc/ceph/$cluster.keyring`` +- ``/etc/ceph/keyring`` +- ``/etc/ceph/keyring.bin`` + +The ``$cluster`` metavariable found in the first two default keyring names above +is your Ceph cluster name as defined by the name of the Ceph configuration +file: for example, if the Ceph configuration file is named ``ceph.conf``, +then your Ceph cluster name is ``ceph`` and the second name above would be +``ceph.keyring``. The ``$name`` metavariable is the user type and user ID: +for example, given the user ``client.admin``, the first name above would be +``ceph.client.admin.keyring``. + +.. note:: When running commands that read or write to ``/etc/ceph``, you might + need to use ``sudo`` to run the command as ``root``. + +After you create a user (for example, ``client.ringo``), you must get the key and add +it to a keyring on a Ceph client so that the user can access the Ceph Storage +Cluster. + +The `User Management`_ section details how to list, get, add, modify, and delete +users directly in the Ceph Storage Cluster. In addition, Ceph provides the +``ceph-authtool`` utility to allow you to manage keyrings from a Ceph client. + +Creating a Keyring +------------------ + +When you use the procedures in the `Managing Users`_ section to create users, +you must provide user keys to the Ceph client(s). This is required so that the Ceph client(s) +can retrieve the key for the specified user and authenticate that user against the Ceph +Storage Cluster. Ceph clients access keyrings in order to look up a user name and +retrieve the user's key. + +The ``ceph-authtool`` utility allows you to create a keyring. To create an +empty keyring, use ``--create-keyring`` or ``-C``. For example: + +.. prompt:: bash $ + + ceph-authtool --create-keyring /path/to/keyring + +When creating a keyring with multiple users, we recommend using the cluster name +(of the form ``$cluster.keyring``) for the keyring filename and saving the keyring in the +``/etc/ceph`` directory. By doing this, you ensure that the ``keyring`` configuration default setting +will pick up the filename without requiring you to specify the filename in the local copy +of your Ceph configuration file. For example, you can create ``ceph.keyring`` by +running the following command: + +.. prompt:: bash $ + + sudo ceph-authtool -C /etc/ceph/ceph.keyring + +When creating a keyring with a single user, we recommend using the cluster name, +the user type, and the user name, and saving the keyring in the ``/etc/ceph`` directory. +For example, we recommend that the ``client.admin`` user use ``ceph.client.admin.keyring``. + +To create a keyring in ``/etc/ceph``, you must do so as ``root``. This means +that the file will have ``rw`` permissions for the ``root`` user only, which is +appropriate when the keyring contains administrator keys. However, if you +intend to use the keyring for a particular user or group of users, be sure to use ``chown`` or ``chmod`` to establish appropriate keyring +ownership and access. + +Adding a User to a Keyring +-------------------------- + +When you :ref:`Add a user<rados_ops_adding_a_user>` to the Ceph Storage +Cluster, you can use the `Getting a User`_ procedure to retrieve a user, key, +and capabilities and then save the user to a keyring. + +If you want to use only one user per keyring, the `Getting a User`_ procedure with +the ``-o`` option will save the output in the keyring file format. For example, +to create a keyring for the ``client.admin`` user, run the following command: + +.. prompt:: bash $ + + sudo ceph auth get client.admin -o /etc/ceph/ceph.client.admin.keyring + +Notice that the file format in this command is the file format conventionally used when manipulating the keyrings of individual users. + +If you want to import users to a keyring, you can use ``ceph-authtool`` +to specify the destination keyring and the source keyring. +For example: + +.. prompt:: bash $ + + sudo ceph-authtool /etc/ceph/ceph.keyring --import-keyring /etc/ceph/ceph.client.admin.keyring + +Creating a User +--------------- + +Ceph provides the `Adding a User`_ function to create a user directly in the Ceph +Storage Cluster. However, you can also create a user, keys, and capabilities +directly on a Ceph client keyring, and then import the user to the Ceph +Storage Cluster. For example: + +.. prompt:: bash $ + + sudo ceph-authtool -n client.ringo --cap osd 'allow rwx' --cap mon 'allow rwx' /etc/ceph/ceph.keyring + +For additional details on capabilities, see `Authorization (Capabilities)`_. + +You can also create a keyring and add a new user to the keyring simultaneously. +For example: + +.. prompt:: bash $ + + sudo ceph-authtool -C /etc/ceph/ceph.keyring -n client.ringo --cap osd 'allow rwx' --cap mon 'allow rwx' --gen-key + +In the above examples, the new user ``client.ringo`` has been added only to the +keyring. The new user has not been added to the Ceph Storage Cluster. + +To add the new user ``client.ringo`` to the Ceph Storage Cluster, run the following command: + +.. prompt:: bash $ + + sudo ceph auth add client.ringo -i /etc/ceph/ceph.keyring + +Modifying a User +---------------- + +To modify the capabilities of a user record in a keyring, specify the keyring +and the user, followed by the capabilities. For example: + +.. prompt:: bash $ + + sudo ceph-authtool /etc/ceph/ceph.keyring -n client.ringo --cap osd 'allow rwx' --cap mon 'allow rwx' + +To update the user in the Ceph Storage Cluster, you must update the user +in the keyring to the user entry in the Ceph Storage Cluster. To do so, run the following command: + +.. prompt:: bash $ + + sudo ceph auth import -i /etc/ceph/ceph.keyring + +For details on updating a Ceph Storage Cluster user from a +keyring, see `Importing a User`_ + +You may also :ref:`Modify user capabilities<modify-user-capabilities>` directly in the cluster, store the +results to a keyring file, and then import the keyring into your main +``ceph.keyring`` file. + +Command Line Usage +================== + +Ceph supports the following usage for user name and secret: + +``--id`` | ``--user`` + +:Description: Ceph identifies users with a type and an ID: the form of this user identification is ``TYPE.ID``, and examples of the type and ID are + ``client.admin`` and ``client.user1``. The ``id``, ``name`` and + ``-n`` options allow you to specify the ID portion of the user + name (for example, ``admin``, ``user1``, ``foo``). You can specify + the user with the ``--id`` and omit the type. For example, + to specify user ``client.foo``, run the following commands: + + .. prompt:: bash $ + + ceph --id foo --keyring /path/to/keyring health + ceph --user foo --keyring /path/to/keyring health + + +``--name`` | ``-n`` + +:Description: Ceph identifies users with a type and an ID: the form of this user identification is ``TYPE.ID``, and examples of the type and ID are + ``client.admin`` and ``client.user1``. The ``--name`` and ``-n`` + options allow you to specify the fully qualified user name. + You are required to specify the user type (typically ``client``) with the + user ID. For example: + + .. prompt:: bash $ + + ceph --name client.foo --keyring /path/to/keyring health + ceph -n client.foo --keyring /path/to/keyring health + + +``--keyring`` + +:Description: The path to the keyring that contains one or more user names and + secrets. The ``--secret`` option provides the same functionality, + but it does not work with Ceph RADOS Gateway, which uses + ``--secret`` for another purpose. You may retrieve a keyring with + ``ceph auth get-or-create`` and store it locally. This is a + preferred approach, because you can switch user names without + switching the keyring path. For example: + + .. prompt:: bash $ + + sudo rbd map --id foo --keyring /path/to/keyring mypool/myimage + + +.. _pools: ../pools + +Limitations +=========== + +The ``cephx`` protocol authenticates Ceph clients and servers to each other. It +is not intended to handle authentication of human users or application programs +that are run on their behalf. If your access control +needs require that kind of authentication, you will need to have some other mechanism, which is likely to be specific to the +front end that is used to access the Ceph object store. This other mechanism would ensure that only acceptable users and programs are able to run on the +machine that Ceph permits to access its object store. + +The keys used to authenticate Ceph clients and servers are typically stored in +a plain text file on a trusted host. Appropriate permissions must be set on the plain text file. + +.. important:: Storing keys in plaintext files has security shortcomings, but + they are difficult to avoid, given the basic authentication methods Ceph + uses in the background. Anyone setting up Ceph systems should be aware of + these shortcomings. + +In particular, user machines, especially portable machines, should not +be configured to interact directly with Ceph, since that mode of use would +require the storage of a plaintext authentication key on an insecure machine. +Anyone who stole that machine or obtained access to it could +obtain a key that allows them to authenticate their own machines to Ceph. + +Instead of permitting potentially insecure machines to access a Ceph object +store directly, you should require users to sign in to a trusted machine in +your environment, using a method that provides sufficient security for your +purposes. That trusted machine will store the plaintext Ceph keys for the +human users. A future version of Ceph might address these particular +authentication issues more fully. + +At present, none of the Ceph authentication protocols provide secrecy for +messages in transit. As a result, an eavesdropper on the wire can hear and understand +all data sent between clients and servers in Ceph, even if the eavesdropper cannot create or +alter the data. Similarly, Ceph does not include options to encrypt user data in the +object store. Users can, of course, hand-encrypt and store their own data in the Ceph +object store, but Ceph itself provides no features to perform object +encryption. Anyone storing sensitive data in Ceph should consider +encrypting their data before providing it to the Ceph system. + + +.. _Architecture - High Availability Authentication: ../../../architecture#high-availability-authentication +.. _Cephx Config Reference: ../../configuration/auth-config-ref |