system.roles Collection¶
2.6 新版功能.
On this page
The system.roles collection in the admin database stores the user-defined roles. To create and manage these user-defined roles, MongoDB provides role management commands.
system.roles Schema¶
The documents in the system.roles collection have the following schema:
{
_id: <system-defined id>,
role: "<role name>",
db: "<database>",
privileges:
[
{
resource: { <resource> },
actions: [ "<action>", ... ]
},
...
],
roles:
[
{ role: "<role name>", db: "<database>" },
...
]
}
A system.roles document has the following fields:
- admin.system.roles.role¶
The role field is a string that specifies the name of the role.
- admin.system.roles.db¶
The db field is a string that specifies the database to which the role belongs. MongoDB uniquely identifies each role by the pairing of its name (i.e. role) and its database.
- admin.system.roles.privileges¶
The privileges array contains the privilege documents that define the privileges for the role.
A privilege document has the following syntax:
{ resource: { <resource> }, actions: [ "<action>", ... ] }
Each privilege document has the following fields:
- admin.system.roles.privileges[n].resource¶
A document that specifies the resources upon which the privilege actions apply. The document has one of the following form:
{ db: <database>, collection: <collection> }
or
{ cluster : true }
See Resource Document for more details.
- admin.system.roles.privileges[n].actions¶
An array of actions permitted on the resource. For a list of actions, see Privilege Actions.
- admin.system.roles.roles¶
The roles array contains role documents that specify the roles from which this role inherits privileges.
A role document has the following syntax:
{ role: "<role name>", db: "<database>" }
A role document has the following fields:
- admin.system.roles.roles[n].role¶
The name of the role. A role can be a built-in role provided by MongoDB or a user-defined role.
- admin.system.roles.roles[n].db¶
The name of the database where the role is defined.
Examples¶
Consider the following sample documents found in system.roles collection of the admin database.
A User-Defined Role Specifies Privileges¶
The following is a sample document for a user-defined role appUser defined for the myApp database:
{
_id: "myApp.appUser",
role: "appUser",
db: "myApp",
privileges: [
{ resource: { db: "myApp" , collection: "" },
actions: [ "find", "createCollection", "dbStats", "collStats" ] },
{ resource: { db: "myApp", collection: "logs" },
actions: [ "insert" ] },
{ resource: { db: "myApp", collection: "data" },
actions: [ "insert", "update", "remove", "compact" ] },
{ resource: { db: "myApp", collection: "system.js" },
actions: [ "find" ] },
],
roles: []
}
The privileges array lists the five privileges that the appUser role specifies:
- The first privilege permits its actions ( "find", "createCollection", "dbStats", "collStats") on all the collections in the myApp database excluding its system collections. See Specify a Database as Resource.
- The next two privileges permits additional actions on specific collections, logs and data, in the myApp database. See Specify a Collection of a Database as Resource.
- The last privilege permits actions on one system collections in the myApp database. While the first privilege gives database-wide permission for the find action, the action does not apply to myApp‘s system collections. To give access to a system collection, a privilege must explicitly specify the collection. See Resource Document.
As indicated by the empty roles array, appUser inherits no additional privileges from other roles.
User-Defined Role Inherits from Other Roles¶
The following is a sample document for a user-defined role appAdmin defined for the myApp database: The document shows that the appAdmin role specifies privileges as well as inherits privileges from other roles:
{
_id: "myApp.appAdmin",
role: "appAdmin",
db: "myApp",
privileges: [
{
resource: { db: "myApp", collection: "" },
actions: [ "insert", "dbStats", "collStats", "compact", "repairDatabase" ]
}
],
roles: [
{ role: "appUser", db: "myApp" }
]
}
The privileges array lists the privileges that the appAdmin role specifies. This role has a single privilege that permits its actions ( "insert", "dbStats", "collStats", "compact", "repairDatabase") on all the collections in the myApp database excluding its system collections. See Specify a Database as Resource.
The roles array lists the roles, identified by the role names and databases, from which the role appAdmin inherits privileges.