[role="xpack"]
[[defining-roles]]
=== Defining roles

A role is defined by the following JSON structure:

[source,js]
-----
{
  "run_as": [ ... ], <1>
  "cluster": [ ... ], <2>
  "global": { ... }, <3>
  "indices": [ ... ], <4>
  "applications": [ ... ] <5>

}
-----
// NOTCONSOLE

<1> A list of usernames the owners of this role can <<run-as-privilege, impersonate>>.
<2> A list of cluster privileges. These privileges define the
    cluster level actions users with this role are able to execute. This field
    is optional (missing `cluster` privileges effectively mean no cluster level
    permissions).
<3> An object defining global privileges. A global privilege is a form of
    cluster privilege that is request sensitive. A standard cluster privilege
    makes authorization decisions based solely on the action being executed.
    A global privilege also considers the parameters included in the request.
    Support for global privileges is currently limited to the management of
    application privileges. This field is optional.
<4> A list of indices permissions entries. This field is optional (missing `indices`
    privileges effectively mean no index level permissions).
<5> A list of application privilege entries. This field is optional.

[[valid-role-name]]
NOTE: Role names must be at least 1 and no more than 1024 characters. They can
      contain alphanumeric characters (`a-z`, `A-Z`, `0-9`), spaces,
      punctuation, and printable symbols in the {wikipedia}/Basic_Latin_(Unicode_block)[Basic Latin (ASCII) block].
      Leading or trailing whitespace is not allowed.

[[roles-indices-priv]]
==== Indices Privileges

The following describes the structure of an indices permissions entry:

[source,js]
-------
{
  "names": [ ... ], <1>
  "privileges": [ ... ], <2>
  "field_security" : { ... }, <3>
  "query": "..." <4>
  "allow_restricted_indices": false <5>
}
-------
// NOTCONSOLE

<1> A list of data streams, indices, and aliases to which the permissions
    in this entry apply. Supports wildcards (`*`).
<2> The index level privileges the owners of the role have on the associated
    data streams and indices specified in the `names` argument.
<3> Specification for document fields the owners of the role have read access to.
    See <<field-and-document-access-control>> for details.
<4> A search query that defines the documents the owners of the role have read
    access to. A document within the associated data streams and indices must match this query
    in order for it to be accessible by the owners of the role.
<5> Restricted indices are a special category of indices that are used
    internally to store configuration data. Only internal system
    roles should normally grant privileges over the restricted indices.
    **Toggling this flag is most discouraged because it could effectively grant
    superuser privileges.** If however, for administrative purposes, you need to
    create a role with privileges covering restricted indices, you must set
    this field to `true` (default is `false`), and then the `names` field will
    cover the restricted indices as well.

[TIP]
==============================================================================
The `names` parameter accepts wildcard and regular expressions that may refer to
multiple data streams, indices, and aliases.

* Wildcard (default) - simple wildcard matching where `*` is a placeholder
  for zero or more characters, `?` is a placeholder for a single character
  and `\` may be used as an escape character.

* Regular Expressions - A more powerful syntax for matching more complex
  patterns. This regular expression is based on Lucene's regexp automaton
  syntax. To enable this syntax, it must be wrapped within a pair of
  forward slashes (`/`). Any pattern starting with `/` and not ending with
  `/` is considered to be malformed.

.Example Regular Expressions
[source,yaml]
------------------------------------------------------------------------------
"foo-bar":               # match the literal `foo-bar`
"foo-*":                 # match anything beginning with "foo-"
"logstash-201?-*":       # ? matches any one character
"/.*-201[0-9]-.*/":      # use a regex to match anything containing 2010-2019
"/foo":                  # syntax error - missing final /
------------------------------------------------------------------------------
==============================================================================

[[roles-global-priv]]
==== Global Privileges
The following describes the structure of a global privileges entry:

[source,js]
-------
{
  "application": {
    "manage": {    <1>
        "applications": [ ... ] <2>
    }
  }
}
-------
// NOTCONSOLE

<1> The only supported global privilege is the ability to manage application
    privileges
<2> The list of application names that may be managed. This list supports
    wildcards (e.g. `"myapp-*"`) and regular expressions (e.g.
    `"/app[0-9]*/"`)

[[roles-application-priv]]
==== Application Privileges
The following describes the structure of an application privileges entry:

[source,js]
-------
{
  "application": "my_app", <1>
  "privileges": [ ... ],   <2>
  "resources": [ ... ]     <3>
}
-------
// NOTCONSOLE

<1> The name of the application.
<2> The list of the names of the application privileges to grant to this role.
<3> The resources to which those privileges apply. These are handled in the same
    way as index name pattern in `indices` permissions. These resources do not
    have any special meaning to the {es} {security-features}.

For details about the validation rules for these fields, see the
{ref}/security-api-put-privileges.html[add application privileges API].

A role may refer to application privileges that do not exist - that is, they
have not yet been defined through the add application privileges API (or they
were defined, but have since been deleted). In this case, the privilege has
no effect, and will not grant any actions in the
{ref}/security-api-has-privileges.html[has privileges API].

==== Example

The following snippet shows an example definition of a `clicks_admin` role:

[source,console]
-----------
POST /_security/role/clicks_admin
{
  "run_as": [ "clicks_watcher_1" ],
  "cluster": [ "monitor" ],
  "indices": [
    {
      "names": [ "events-*" ],
      "privileges": [ "read" ],
      "field_security" : {
        "grant" : [ "category", "@timestamp", "message" ]
      },
      "query": "{\"match\": {\"category\": \"click\"}}"
    }
  ]
}
-----------

Based on the above definition, users owning the `clicks_admin` role can:

  * Impersonate the `clicks_watcher_1` user and execute requests on its behalf.
  * Monitor the {es} cluster
  * Read data from all indices prefixed with `events-`
  * Within these indices, only read the events of the `click` category
  * Within these document, only read the `category`, `@timestamp` and `message`
    fields.

TIP:  For a complete list of available <<security-privileges, cluster and indices privileges>>

There are two available mechanisms to define roles: using the _Role Management APIs_
or in local files on the {es} nodes. You can also implement
custom roles providers. If you need to integrate with another system to retrieve
user roles, you can build a custom roles provider plugin. For more information,
see <<custom-roles-authorization, Customizing Roles and Authorization>>.

[discrete]
[[roles-management-ui]]
=== Role management UI

You can manage users and roles easily in {kib}. To
manage roles, log in to {kib} and go to *Management / Security / Roles*. 

[discrete]
[[roles-management-api]]
=== Role management API

The _Role Management APIs_ enable you to add, update, remove and retrieve roles
dynamically. When you use the APIs to manage roles in the `native` realm, the
roles are stored in an internal {es} index. For more information and examples, 
see {ref}/security-api.html#security-role-apis[role management APIs]. 

[discrete]
[[roles-management-file]]
=== File-based role management

Apart from the _Role Management APIs_, roles can also be defined in local
`roles.yml` file located in `ES_PATH_CONF`. This is a YAML file where each
role definition is keyed by its name.

[IMPORTANT]
==============================
If the same role name is used in the `roles.yml` file and through the
_Role Management APIs_, the role found in the file will be used.
==============================

While the _Role Management APIs_ is the preferred mechanism to define roles,
using the `roles.yml` file becomes useful if you want to define fixed roles that
no one (beside an administrator having physical access to the {es} nodes)
would be able to change. Please note however, that the `roles.yml` file is provided as a
minimal administrative function and is not intended to cover and be used
to define roles for all use cases.

[IMPORTANT]
==============================
You cannot view, edit, or remove any roles that are defined in `roles.yml` by
using the <<roles-management-ui,role management UI>> or the
<<roles-management-api,role management APIs>>.
==============================

[IMPORTANT]
==============================
The `roles.yml` file is managed locally by the node and is not globally by the
cluster. This means that with a typical multi-node cluster, the exact same
changes need to be applied on each and every node in the cluster.

A safer approach would be to apply the change on one of the nodes and have the
`roles.yml` distributed/copied to all other nodes in the cluster (either
manually or using a configuration management system such as Puppet or Chef).
==============================

The following snippet shows an example of the `roles.yml` file configuration:

[source,yaml]
-----------------------------------
click_admins:
  run_as: [ 'clicks_watcher_1' ]
  cluster: [ 'monitor' ]
  indices:
    - names: [ 'events-*' ]
      privileges: [ 'read' ]
      field_security:
        grant: ['category', '@timestamp', 'message' ]
      query: '{"match": {"category": "click"}}'
-----------------------------------

{es} continuously monitors the `roles.yml` file and automatically picks
up and applies any changes to it.
