diff --git a/doc/Pacemaker_Explained/en-US/Ch-ACLs.txt b/doc/Pacemaker_Explained/en-US/Ch-ACLs.txt index 178a2949e6..0fa34c9a9e 100644 --- a/doc/Pacemaker_Explained/en-US/Ch-ACLs.txt +++ b/doc/Pacemaker_Explained/en-US/Ch-ACLs.txt @@ -1,334 +1,337 @@ :compat-mode: legacy = Access Control Lists (ACLs) = //// We prefer [[ch-acls]], but older versions of asciidoc don't deal well with that construct for chapter headings //// anchor:ch-acls[Chapter 13, ACLs] indexterm:[access control list] indexterm:[ACL] By default, the +root+ user or any user in the +haclient+ group can modify Pacemaker's CIB without restriction. Pacemaker offers 'access control lists (ACLs)' to provide more fine-grained authorization. == ACL Prerequisites == In order to use ACLs: * The Pacemaker software must have been compiled with ACL support. If the output of the command `pacemakerd --features` contains `acls`, your installation supports ACLs. * Desired users must have user accounts in the +haclient+ group on all nodes in the cluster. * If your CIB was created before Pacemaker 1.1.12, it may need to be updated to the current schema using `cibadmin --upgrade` in order to use the syntax documented here. * The +enable-acl+ <> must be set to true. == ACL Configuration == ACLs are specified within an +acls+ element of the CIB. The +acls+ element may contain any number of +acl_role+, +acl_target+, and +acl_group+ elements. == ACL Roles == An ACL role is a collection of permissions allowing or denying access to particular portions of the CIB. .Properties of an ACL Role [width="95%",cols="1m,<3",options="header",align="center"] |==== |Attribute |Description |id |A unique name for the role (required) indexterm:[id,acl_role] indexterm:[access control list,acl_role,id] |description |Arbitrary text (not used by Pacemaker) indexterm:[description,acl_role] indexterm:[access control list,acl_role,description] |==== An +acl_role+ element may contain any number of +acl_permission+ elements. .Properties of an ACL Permission [width="95%",cols="1m,<3",options="header",align="center"] |==== |Attribute |Description |id |A unique name for the permission (required) indexterm:[id,acl_permission] indexterm:[access control list,acl_permission,id] |description |Arbitrary text (not used by Pacemaker) indexterm:[description,acl_permission] indexterm:[access control list,acl_permission,description] |kind |The access being granted. Allowed values are +read+, +write+, and +deny+. A value of +write+ grants both read and write access. indexterm:[kind,acl_permission] indexterm:[access control list,acl_permission,kind] |object-type |The name of an XML element in the CIB to which the permission applies. (Exactly one of +object-type+, +xpath+, and +reference+ must be specified for a permission.) indexterm:[object-type,acl_permission] indexterm:[access control list,acl_permission,object-type] |attribute |If specified, the permission applies only to +object-type+ elements that have this attribute set (to any value). If not specified, the permission applies to all +object-type+ elements. May only be used with +object-type+. indexterm:[attribute,acl_permission] indexterm:[access control list,acl_permission,attribute] |reference |The ID of an XML element in the CIB to which the permission applies. (Exactly one of +object-type+, +xpath+, and +reference+ must be specified for a permission.) indexterm:[reference,acl_permission] indexterm:[access control list,acl_permission,reference] |xpath |An https://www.w3.org/TR/xpath-10/[XPath] specification selecting an XML element in the CIB to which the permission applies. Attributes may be specified in the XPath to select particular elements, but the permissions apply to the entire element. (Exactly one of +object-type+, +xpath+, and +reference+ must be specified for a permission.) indexterm:[xpath,acl_permission] indexterm:[access control list,acl_permission,xpath] |==== [IMPORTANT] ==== * Permissions are applied to the selected XML element's entire XML subtree (all elements enclosed within it). * Write permission grants the ability to create, modify, or remove the element and its subtree, and also the ability to create any "scaffolding" elements (enclosing elements that do not have attributes other than an ID). * Permissions for more specific matches (more deeply nested elements) take precedence over more general ones. * If multiple permissions are configured for the same match (for example, in different roles applied to the same user), any +deny+ permission takes precedence, then +write+, then lastly +read+. ==== == ACL Targets and Groups == ACL targets correspond to user accounts on the system. .Properties of an ACL Target [width="95%",cols="1m,<3",options="header",align="center"] |==== |Attribute |Description |id |The name of a user on the system (required) indexterm:[id,acl_target] indexterm:[access control list,acl_target,id] |==== ACL groups may be specified, but are not currently used by Pacemaker. This is expected to change in a future version. .Properties of an ACL Group [width="95%",cols="1m,<3",options="header",align="center"] |==== |Attribute |Description |id |The name of a group on the system (required) indexterm:[id,acl_group] indexterm:[access control list,acl_group,id] |==== Each +acl_target+ and +acl_group+ element may contain any number of +role+ elements. .Properties of an ACL Role Reference [width="95%",cols="1m,<3",options="header",align="center"] |==== |Attribute |Description |id |The +id+ of an +acl_role+ element that specifies permissions granted to the enclosing target or group indexterm:[id,role] indexterm:[access control list,role,id] |==== [IMPORTANT] ==== The +root+ and +hacluster+ user accounts always have full access to the CIB, regardless of ACLs. For other user accounts, when +enable-acl+ is true, permission to all parts of the CIB is denied by default (permissions must be explicitly granted). ==== == ACL Examples == [source,XML] ---- - + + + xpath="//resources//meta_attributes/nvpair[@name='target-role']" /> + xpath="//nvpair[@name='maintenance']"/> + xpath="//resources//meta_attributes/nvpair[@name='target-role']"/> + xpath="//resources//meta_attributes/nvpair[@name='is-managed']"/> ---- In the above example, the user +alice+ has the minimal permissions necessary to run basic Pacemaker CLI tools, including using `crm_mon` to view the cluster status, without being able to modify anything. The user +bob+ can view the entire configuration and status of the cluster, but not make any changes. The user +carol+ can read everything, and change selected cluster properties as well as resource roles and location constraints. Finally, +dave+ has full read and write access to the entire CIB. Looking at the +minimal+ role in more depth, it is designed to allow read access to the +cib+ tag itself, while denying access to particular portions of its subtree (which is the entire CIB). This is because the DC node is indicated in the +cib+ tag, so `crm_mon` will not be able to report the DC otherwise. However, this does change the security model to allow by default, since any portions of the CIB not explicitly denied will be readable. The +cib+ read access could be removed and replaced with read access to just the +crm_config+ and +status+ sections, for a safer approach at the cost of not seeing the DC in status output. For a simpler configuration, the +minimal+ role allows read access to the entire +crm_config+ section, which contains cluster properties. It would be possible to allow read access to specific properties instead (such as +stonith-enabled+, +dc-uuid+, +have-quorum+, and +cluster-name+) to restrict access further while still allowing status output, but cluster properties are unlikely to be considered sensitive.