Cratus

Cratus is a simple library, primarily used by KnuEdge to query, report on, and manage Active Directory users and groups via LDAP. The intention is to simplify this interaction and modularize it for use across several of our tools. We've open-sourced it because we think it might be useful to others, and to give back to the community from whence all of its capabilities are derived.

Why not just use Net::LDAP? Well, in fact, this library does use Net::LDAP, but does so making some assumptions based on how we (and arguably most people) use LDAP with Active Directory. By building linkages between users and groups, baking in recursion (supporting so-called nested groups), and making just the right things configurable, Cratus provides a simple interface for common LDAP admin tasks. That said, it isn't meant to be general-purpose LDAP libary, so it hides a lot and is opinionated. If you're using Active Directory and not doing strange things with it, this library might be helpful.

Add this line to your application's Gemfile:

gem 'cratus'

And then execute:

$ bundle

Or install it yourself as:

$ gem install cratus

Make sure your application has required the gem:

require 'cratus'

Cratus supports configuration settings, controlled via the following keys with the following default values:

  {
    group_dn_attribute: :cn,
    group_member_attribute: :member,
    group_description_attribute: :description,
    group_objectclass: :group,
    group_basedn: 'ou=groups,dc=example,dc=com',
    group_memberof_attribute: :memberOf,
    user_dn_attribute: :samaccountname,
    user_objectclass: :user,
    user_basedn: 'ou=users,dc=example,dc=com',
    user_account_control_attribute: :userAccountControl,
    user_department_attribute: :department,
    user_lockout_attribute: :lockouttime,
    user_mail_attribute: :mail,
    user_displayname_attribute: :displayName,
    user_memberof_attribute: :memberOf,
    host: 'ldap.example.com',
    port: 389,
    basedn: 'dc=example,dc=com',
    username: 'username',
    password: 'p@assedWard!',
    include_distribution_groups: true
  }

These keys can be set in the following ways:

• A YAML Config file at ~/.cratus.yml in the form of:

---
:basedn: ou=internal,dc=mycompany,dc=com
:host: ad1.mycompany.com
:username: cn=ldapUser,ou=serviceAccounts,ou=users,ou=internal,dc=mycompany,dc=com
:password: 'mySuperSecretP@ssw0rd'
:user_basedn: ou=users,ou=internal,dc=mycompany,dc=com
:group_basedn: ou=groups,ou=internal,dc=mycompany,dc=com

• Environment variables (all uppercase with CRATUS_ prepended) in the form of:

export CRATUS_BASEDN="ou=internal,dc=mycompany,dc=com"
export CRATUS_HOST="ad1.mycompany.com"
...

• In code, by calling setter methods on the Config singleton:

Cratus.config.basedn = 'ou=internal,dc=mycompany,dc=com'
Cratus.config.host   = 'ad1.mycompany.com'

With Cratus configured, you'll need to connect to LDAP:

Cratus::LDAP.connect

After connecting, using Cratus involves using the model classes User and Group.

The Group class supports the following finder methods:

• Cratus::Group.all returns an Array<Cratus::Group> of all groups scoped at or below the group_basedn.
• Cratus::Group.new('name') creates a new instance populated with details from LDAP (or raises Cratus::Exceptions::FailedLDAPSearch if the group can't be found).

Instances of Group have the following read-only attributes and methods:

• #members provides an Array<Cratus::User> of all users that are a member of the group. It does this recursively, so it supports nested groups.
• #member_groups provides an Array<Cratus::Group> of all groups that are a member of the group. It does this recursively, so it supports nested groups.
• #member_of provides an Array<Cratus::Group> of all groups that this group is a member of. It does this recursively, so it supports nested groups.
• #dn returns the distinguished name (dn) of the LDAP object
• #description returns the configurable LDAP "description" attribute as stored in LDAP if it exists. Otherwise it returns nil.

Instances of Group have the following methods that can change the underlying LDAP object:

• #add_user(user) allows adding individual LDAP users to a group. This method takes as input an instance of Cratus::User. It is idempotent and will add users as direct members of the group unless the user is already a member (directly or indirectly).
• #remove_user(user) allows removing individual LDAP users from a group. This method takes as input an instance of Cratus::User. It is idempotent and will remove users that are direct members of the group.

The Group class also implements Comparable, so it supports common comparison methods, most notably ==.

The User class supports the following finder methods:

• Cratus::User.all returns an Array of all users scoped at or below the user_basedn.
• Cratus::User.new('name') creates a new instance populated with details from LDAP (or raises Cratus::Exceptions::FailedLDAPSearch if the group can't be found).

Instances of User have the following read-only attributes and methods:

• #department returns the LDAP "department" attribute as stored in LDAP if it exists. Otherwise it returns nil.
• #disabled? returns true of false to indicate whether the User is fully disabled in LDAP.
• #email returns the configurable LDAP "mail" attribute as stored in LDAP if it exists. Otherwise it returns nil.
• #enabled? returns true of false to indicate whether the User is fully enabled in LDAP.
• #fullname returns the configurable LDAP "displayName" attribute as stored in LDAP if it exists. Otherwise it returns nil.
• #lockouttime returns the configurable LDAP "lockouttime" attribute as stored in LDAP if it exists. Otherwise it returns 0.
• #lockoutduration queries the Active Directory basedn for the lockoutDuration attribute for use in calculations with #lockouttime.
• #locked? returns true or false based on #lockouttime and #lockoutduration.
• #member_of provides an Array<Cratus::Group> of all groups that this user is a member of. It does this recursively, so it supports nested groups.
• #dn returns the distinguished name (dn) of the LDAP object

Instances of User have the following methods that can change the underlying LDAP object:

• #add_to_group(group) allows adding an LDAP user to a group. This method takes as input an instance of Cratus::Group. It is idempotent and will add users as direct members of the group unless the user is already a member (directly or indirectly).
• #remove_from_group(group) allows removing an LDAP user from a group. This method takes as input an instance of Cratus::Group. It is idempotent and will remove the user if it is a direct members of the group.
• #disable changes the User Account Control (usually userAccountControl) attribute to 514, signifying that logins are not allowed.
• #enable changes the User Account Control (usually userAccountControl) attribute to 512, signifying that logins are allowed.
• #unlock changes the lockouttime atrribute to 0, signifying that the account is not locked out.

The User class also implements Comparable, so it supports common comparison methods, most notably ==.

See CONTRIBUTING for additional information.

This project and all code contained within it are released under the MIT License. As stated in CONTRIBUTING:

All contributions to this project will be released under the MIT License. By submitting a pull request, you are agreeing to comply with this license and for any contributions to be released under it.