clarify that privileges are always part of roles

[pve-docs.git] / pveum.adoc

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================
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NAME
----

pveum - Proxmox VE User Manager


SYNOPSYS
--------

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DESCRIPTION
-----------
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User Management
===============
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// Copied from pve wiki: Revision as of 16:10, 27 October 2015

Proxmox VE supports multiple authentication sources, e.g. Linux PAM,
an integrated Proxmox VE authentication server, LDAP, Microsoft Active
Directory.

By using the role based user- and permission management for all
objects (VMs, storages, nodes, etc.) granular access can be defined.


Users
-----

{pve} stores user attributes in `/etc/pve/user.cfg`.
Passwords are not stored here, users are instead associated with
<<authentication-realms,authentication realms>> described below.
Therefore a user is internally often identified by its name and
realm in the form `<userid>@<realm>`.

Each user entry in this file contains the following information:

* First name
* Last name
* E-mail address
* Group memberships
* An optional Expiration date
* A comment or note about this user
* Whether this user is enabled or disabled
* Optional two factor authentication keys


System administrator
~~~~~~~~~~~~~~~~~~~~

The system's root user can always log in via the Linux PAM realm and is an
unconfined administrator. This user cannot be deleted, but attributes can
still be changed and system mails will be sent to the email address
assigned to this user.


Groups
~~~~~~

Each user can be member of several groups. Groups are the preferred
way to organize access permissions. You should always grant permission
to groups instead of using individual users. That way you will get a
much shorter access control list which is easier to handle.


[[authentication-realms]]
Authentication Realms
---------------------

As {pve} users are just counterparts for users existing on some external
realm, the realms have to be configured in `/etc/pve/domains.cfg`.
The following realms (authentication methods) are available:

Linux PAM standard authentication::
In this case a system user has to exist (eg. created via the `adduser`
command) on all nodes the user is allowed to login, and the user
authenticates with their usual system password.
+
[source,bash]
----
useradd heinz
passwd heinz
groupadd watchman
usermod -a -G watchman heinz
----

Proxmox VE authentication server::
This is a unix like password store (`/etc/pve/priv/shadow.cfg`).
Password are encrypted using the SHA-256 hash method.
This is the most convenient method for for small (or even medium)
installations where users do not need access to anything outside of
{pve}. In this case users are fully managed by {pve} and are able to
change their own passwords via the GUI.

LDAP::
It is possible to authenticate users via an LDAP server (eq.
openldap). The server and an optional fallback server can be
configured and the connection can be encrypted via SSL.
+
Users are searched under a 'Base Domain Name' (`base_dn`), with the
user name found in the attribute specified in the 'User Attribute Name'
(`user_attr`) field.
+
For instance, if a user is represented via the
following ldif dataset:
+
----
# user1 of People at ldap-test.com
dn: uid=user1,ou=People,dc=ldap-test,dc=com
objectClass: top
objectClass: person
objectClass: organizationalPerson
objectClass: inetOrgPerson
uid: user1
cn: Test User 1
sn: Testers
description: This is the first test user.
----
+
The 'Base Domain Name' would be `ou=People,dc=ldap-test,dc=com` and the user
attribute would be `uid`.
+
If {pve} needs to authenticate (bind) to the ldap server before being
able to query and authenticate users, a bind domain name can be
configured via the `bind_dn` property in `/etc/pve/domains.cfg`. Its
password then has to be stored in `/etc/pve/priv/ldap/<realmname>.pw`
(eg. `/etc/pve/priv/ldap/my-ldap.pw`). This file should contain a
single line containing the raw password.

Microsoft Active Directory::

A server and authentication domain need to be specified. Like with
ldap an optional fallback server, optional port, and SSL
encryption can be configured.


Two factor authentication
-------------------------

Each realm can optionally be secured additionally by two factor
authentication. This can be done by selecting one of the available methods
via the 'TFA' dropdown box when adding or editing an Authentication Realm.
When a realm has TFA enabled it becomes a requirement and only users with
configured TFA will be able to login.

Currently there are two methods available:

Time based OATH (TOTP)::
This uses the standard HMAC-SHA1 algorithm where the current time is hashed
with the user's configured key. The time step and password length
parameters are configured.
+
A user can have multiple keys configured (separated by spaces), and the
keys can be specified in Base32 (RFC3548) or hexadecimal notation.
+
{pve} provides a key generation tool (`oathkeygen`) which prints out a
random key in Base32 notation which can be used directly with various OTP
tools, such as the `oathtool` command line tool, the Google authenticator
or FreeOTP Android apps.

YubiKey OTP::
For authenticating via a YubiKey a Yubico API ID, API KEY and validation
server URL must be configured, and users must have a YubiKey available. In
order to get the key ID from a YubiKey, you can trigger the YubiKey once
after connecting it to USB and copy the first 12 characters of the typed
password into the user's 'Key IDs' field.
+
Please refer to the
https://developers.yubico.com/OTP/[YubiKey OTP] documentation for how to use the
https://www.yubico.com/products/services-software/yubicloud/[YubiCloud] or
https://developers.yubico.com/Software_Projects/YubiKey_OTP/YubiCloud_Validation_Servers/[
host your own verification server].


Permission Management
---------------------

In order for a user to perform an action (such as listing, modifying or
deleting a parts of a VM configuration), the user needs to have the
appropriate permissions.

{pve} uses a role and path based permission management system. An entry in
the permissions table allows a user or group to take on a specific role
when accessing an 'object' or 'path'. This means an such an access rule can
be represented as a triple of '(path, user, role)' or '(path, group,
role)', with the role containing a set of allowed actions, and the path
representing the target of these actions.


Roles
~~~~~

A role is simply a list of privileges. Proxmox VE comes with a number
of predefined roles which satisfies most needs.

* `Administrator`: has all privileges
* `NoAccess`: has no privileges (used to forbid access)
* `PVEAdmin`: can do most things, but miss rights to modify system settings (`Sys.PowerMgmt`, `Sys.Modify`, `Realm.Allocate`).
* `PVEAuditor`: read only access
* `PVEDatastoreAdmin`: create and allocate backup space and templates
* `PVEDatastoreUser`: allocate backup space and view storage
* `PVEPoolAdmin`: allocate pools
* `PVESysAdmin`: User ACLs, audit, system console and system logs
* `PVETemplateUser`: view and clone templates
* `PVEUserAdmin`: user administration
* `PVEVMAdmin`: fully administer VMs
* `PVEVMUser`: view, backup, config CDROM, VM console, VM power management

You can see the whole set of predefined roles on the GUI.

Adding new roles can currently only be done from the command line, like
this:

[source,bash]
----
pveum roleadd PVE_Power-only -privs "VM.PowerMgmt VM.Console"
pveum roleadd Sys_Power-only -privs "Sys.PowerMgmt Sys.Console"
----


Objects and Paths
~~~~~~~~~~~~~~~~~

Access permissions are assigned to objects, such as a virtual machines
(`/vms/{vmid}`) or a storage (`/storage/{storeid}`) or a pool of
resources (`/pool/{poolname}`). We use file system like paths to
address those objects. Those paths form a natural tree, and
permissions can be inherited down that hierarchy.


Privileges
~~~~~~~~~~

A privilege is the right to perform a specific action. To simplify
management, lists of privileges are grouped into roles, which can then
be used in the permission table. Note that privileges cannot directly be
assigned to users and paths without being part of a role.

We currently use the following privileges:

Node / System related privileges::

* `Permissions.Modify`: modify access permissions
* `Sys.PowerMgmt`: Node power management (start, stop, reset, shutdown, ...)
* `Sys.Console`: console access to Node
* `Sys.Syslog`: view Syslog
* `Sys.Audit`: view node status/config
* `Sys.Modify`: create/remove/modify node network parameters
* `Group.Allocate`: create/remove/modify groups
* `Pool.Allocate`: create/remove/modify a pool
* `Realm.Allocate`: create/remove/modify authentication realms
* `Realm.AllocateUser`: assign user to a realm
* `User.Modify`: create/remove/modify user access and details.

Virtual machine related privileges::

* `VM.Allocate`: create/remove new VM to server inventory
* `VM.Migrate`: migrate VM to alternate server on cluster
* `VM.PowerMgmt`: power management (start, stop, reset, shutdown, ...)
* `VM.Console`: console access to VM
* `VM.Monitor`: access to VM monitor (kvm)
* `VM.Backup`: backup/restore VMs
* `VM.Audit`: view VM config
* `VM.Clone`: clone/copy a VM
* `VM.Config.Disk`: add/modify/delete Disks 
* `VM.Config.CDROM`: eject/change CDROM
* `VM.Config.CPU`: modify CPU settings
* `VM.Config.Memory`: modify Memory settings
* `VM.Config.Network`: add/modify/delete Network devices
* `VM.Config.HWType`: modify emulated HW type
* `VM.Config.Options`: modify any other VM configuration
* `VM.Snapshot`: create/remove VM snapshots

Storage related privileges::

* `Datastore.Allocate`: create/remove/modify a data store, delete volumes
* `Datastore.AllocateSpace`: allocate space on a datastore
* `Datastore.AllocateTemplate`: allocate/upload templates and iso images 
* `Datastore.Audit`: view/browse a datastore


Permissions
~~~~~~~~~~~

Permissions are the way we control access to objects. In technical
terms they are simply a triple containing `<path,user,role>`. This
concept is also known as access control lists. Each permission
specifies a subject (user or group) and a role (set of privileges) on
a specific path.

When a subject requests an action on an object, the framework looks up
the roles assigned to that subject (using the object path). The set of
roles defines the granted privileges.


Inheritance
^^^^^^^^^^^

As mentioned earlier, object paths form a file system like tree, and
permissions can be inherited down that tree (the propagate flag is set
by default). We use the following inheritance rules:

* Permissions for individual users always replace group permissions.
* Permissions for groups apply when the user is member of that group.
* Permissions replace the ones inherited from an upper level.


Pools
~~~~~

Pools can be used to group a set of virtual machines and data
stores. You can then simply set permissions on pools (`/pool/{poolid}`),
which are inherited to all pool members. This is a great way simplify
access control.


What permission do I need?
~~~~~~~~~~~~~~~~~~~~~~~~~~

The required API permissions are documented for each individual
method, and can be found at http://pve.proxmox.com/pve-docs/api-viewer/

The permissions are specified as a list which can be interpreted as a
tree of logic and access-check functions:

`["and", <subtests>...]` and `["or", <subtests>...]`::
Each(`and`) or any(`or`) further element in the current list has to be true.

`["perm", <path>, [ <privileges>... ], <options>...]`::
The `path` is a templated parameter (see <<templated-paths,Objects and
Paths>>). All (or , if the `any` option is used, any) of the listed
privileges must be allowed on the specified path. If a `require-param`
option is specified, then its specified parameter is required even if the
API call's schema otherwise lists it as being optional.

`["userid-group", [ <privileges>... ], <options>...]`::
The callermust have any of the listed privileges on `/access/groups`. In
addition there are two possible checks depending on whether the
`groups_param` option is set:
+
* `groups_param` is set: The API call has a non-optional `groups` parameter
and the caller must have any of the listed privileges on all of the listed
groups.
* `groups_param` is not set: The user passed via the `userid` parameter
must exist and be part of a group on which the caller has any of the listed
privileges (via the `/access/groups/<group>` path).

`["userid-param", "self"]`::
The value provided for the API call's `userid` parameter must refer to the
user performing the action. (Usually in conjunction with `or`, to allow
users to perform an action on themselves even if they don't have elevated
privileges.)

`["userid-param", "Realm.AllocateUser"]`::
The user needs `Realm.AllocateUser` access to `/access/realm/<realm>`, with
`<realm>` refering to the realm of the user passed via the `userid`
parameter. Note that the user does not need to exist in order to be
associated with a realm, since user IDs are passed in the form of
`<username>@<realm>`.

`["perm-modify", <path>]`::
The `path` is a templated parameter (see <<templated-paths,Objects and
Paths>>). The user needs either the `Permissions.Modify` privilege, or,
depending on the path, the following privileges as a possible substitute:
+
* `/storage/...`: additionally requires 'Datastore.Allocate`
* `/vms/...`: additionally requires 'VM.Allocate`
* `/pool/...`: additionally requires 'Pool.Allocate`
+
If the path is empty, `Permission.Modify` on `/access` is required.

Command Line Tool
-----------------

Most users will simply use the GUI to manage users. But there is also
a full featured command line tool called `pveum` (short for ``**P**roxmox
**VE** **U**ser **M**anager''). Please note that all Proxmox VE command
line tools are wrappers around the API, so you can also access those
function through the REST API.

Here are some simple usage examples. To show help type:

[source,bash]
 pveum

or (to show detailed help about a specific command)

[source,bash]
 pveum help useradd

Create a new user:

[source,bash]
 pveum useradd testuser@pve -comment "Just a test"

Set or Change the password (not all realms support that):

[source,bash]
 pveum passwd testuser@pve

Disable a user:

[source,bash]
 pveum usermod testuser@pve -enable 0

Create a new group:

[source,bash]
 pveum groupadd testgroup

Create a new role:

[source,bash]
 pveum roleadd PVE_Power-only -privs "VM.PowerMgmt VM.Console"


Real World Examples
-------------------


Administrator Group
~~~~~~~~~~~~~~~~~~~

One of the most wanted features was the ability to define a group of
users with full administrator rights (without using the root account).

Define the group:

[source,bash]
 pveum groupadd admin -comment "System Administrators"

Then add the permission:

[source,bash]
 pveum aclmod / -group admin -role Administrator

You can finally add users to the new 'admin' group:

[source,bash]
 pveum usermod testuser@pve -group admin


Auditors
~~~~~~~~

You can give read only access to users by assigning the `PVEAuditor`
role to users or groups.

Example1: Allow user `joe@pve` to see everything

[source,bash]
 pveum aclmod / -user joe@pve -role PVEAuditor

Example1: Allow user `joe@pve` to see all virtual machines

[source,bash]
 pveum aclmod /vms -user joe@pve -role PVEAuditor


Delegate User Management
~~~~~~~~~~~~~~~~~~~~~~~~

If you want to delegate user managenent to user `joe@pve` you can do
that with:

[source,bash]
 pveum aclmod /access -user joe@pve -role PVEUserAdmin

User `joe@pve` can now add and remove users, change passwords and
other user attributes. This is a very powerful role, and you most
likely want to limit that to selected realms and groups. The following
example allows `joe@pve` to modify users within realm `pve` if they
are members of group `customers`:

[source,bash]
 pveum aclmod /access/realm/pve -user joe@pve -role PVEUserAdmin
 pveum aclmod /access/groups/customers -user joe@pve -role PVEUserAdmin

NOTE: The user is able to add other users, but only if they are
members of group `customers` and within realm `pve`.


Pools
~~~~~

An enterprise is usually structured into several smaller departments,
and it is common that you want to assign resources to them and
delegate management tasks. A pool is simply a set of virtual machines
and data stores. You can create pools on the GUI. After that you can
add resources to the pool (VMs, Storage).

You can also assign permissions to the pool. Those permissions are
inherited to all pool members.

Lets assume you have a software development department, so we first
create a group

[source,bash]
 pveum groupadd developers -comment "Our software developers"

Now we create a new user which is a member of that group

[source,bash]
 pveum useradd developer1@pve -group developers -password

NOTE: The -password parameter will prompt you for a password

I assume we already created a pool called ``dev-pool'' on the GUI. So we can now assign permission to that pool:

[source,bash]
 pveum aclmod /pool/dev-pool/ -group developers -role PVEAdmin

Our software developers can now administrate the resources assigned to
that pool.


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