External Authentication System

Salt's External Authentication System (eAuth) allows for Salt to pass through command authorization to any external authentication system, such as PAM or LDAP.


eAuth using the PAM external auth system requires salt-master to be run as root as this system needs root access to check authentication.

Access Control System

The external authentication system allows for specific users to be granted access to execute specific functions on specific minions. Access is configured in the master configuration file and uses the access control system:

      - 'web*':
        - test.*
        - network.*
      - .*

The above configuration allows the user thatch to execute functions in the test and network modules on the minions that match the web* target. User steve is given unrestricted access to minion commands.


The PAM module does not allow authenticating as root.

To allow access to wheel modules or runner modules the following @ syntax must be used:

      - '@wheel'   # to allow access to all wheel modules
      - '@runner'  # to allow access to all runner modules
      - '@jobs'    # to allow access to the jobs runner and/or wheel module


The runner/wheel markup is different, since there are no minions to scope the acl to.


Globs will not match wheel or runners! They must be explicitly allowed with @wheel or @runner.

The external authentication system can then be used from the command-line by any user on the same system as the master with the -a option:

$ salt -a pam web\* test.ping

The system will ask the user for the credentials required by the authentication system and then publish the command.

To apply permissions to a group of users in an external authentication system, append a % to the ID:

      - '*':
        - 'pkg.*'


With external authentication alone, the authentication credentials will be required with every call to Salt. This can be alleviated with Salt tokens.

Tokens are short term authorizations and can be easily created by just adding a -T option when authenticating:

$ salt -T -a pam web\* test.ping

Now a token will be created that has a expiration of 12 hours (by default). This token is stored in a file named salt_token in the active user's home directory.

Once the token is created, it is sent with all subsequent communications. User authentication does not need to be entered again until the token expires.

Token expiration time can be set in the Salt master config file.

LDAP and Active Directory


LDAP usage requires that you have installed python-ldap.

Salt supports both user and group authentication for LDAP (and Active Directory accessed via its LDAP interface)

LDAP configuration happens in the Salt master configuration file.

Server configuration values and their defaults:

auth.ldap.server: localhost
auth.ldap.port: 389
auth.ldap.tls: False
auth.ldap.scope: 2
auth.ldap.uri: ''
auth.ldap.tls: False
auth.ldap.no_verify: False
auth.ldap.anonymous: False
auth.ldap.groupou: 'Groups'
auth.ldap.groupclass: 'posixGroup'
auth.ldap.accountattributename: 'memberUid'

# These are only for Active Directory
auth.ldap.activedirectory: False
auth.ldap.persontype: 'person'

Salt also needs to know which Base DN to search for users and groups and the DN to bind to:

auth.ldap.basedn: dc=saltstack,dc=com
auth.ldap.binddn: cn=admin,dc=saltstack,dc=com

To bind to a DN, a password is required

auth.ldap.bindpw: mypassword

Salt uses a filter to find the DN associated with a user. Salt substitutes the {{ username }} value for the username when querying LDAP

auth.ldap.filter: uid={{ username }}

For OpenLDAP, to determine group membership, one can specify an OU that contains group data. This is prepended to the basedn to create a search path. Then the results are filtered against auth.ldap.groupclass, default posixGroup, and the account's 'name' attribute, memberUid by default.

auth.ldap.groupou: Groups

Active Directory handles group membership differently, and does not utilize the groupou configuration variable. AD needs the following options in the master config:

auth.ldap.activedirectory: True
auth.ldap.filter: sAMAccountName={{username}}
auth.ldap.accountattributename: sAMAccountName
auth.ldap.groupclass: group
auth.ldap.persontype: person

To determine group membership in AD, the username and password that is entered when LDAP is requested as the eAuth mechanism on the command line is used to bind to AD's LDAP interface. If this fails, then it doesn't matter what groups the user belongs to, he or she is denied access. Next, the distinguishedName of the user is looked up with the following LDAP search:

(&(<value of auth.ldap.accountattributename>={{username}})
  (objectClass=<value of auth.ldap.persontype>)

This should return a distinguishedName that we can use to filter for group membership. Then the following LDAP quey is executed:

(&(member=<distinguishedName from search above>)
  (objectClass=<value of auth.ldap.groupclass>)
      - '*':
        - test.ping

To configure an LDAP group, append a % to the ID:

      - '*':
        - test.echo