Petrosian

Active Directory

In this guide we will cover how to manually configure a 7.1 Appliance’s external authentication to work against Active Directory. This provides AD users access to the Appliance UI as well as the REST API.

  1. Enabling Network Manager

  2. Discovering AD Domain

  3. Joining AD Domain

  4. Allowing AD Users to Login to appliance

  5. Configure SSSD

  6. Configure Apache

  7. Configure Administrative UI

In these examples, the AD Domain shown will be EXAMPLE.COM

Enabling Network Manager

By default, the appliance is configured with Network Manager enabled. Having Network Manager enabled allows the realm command to discover the available Active Directory domains that can be joined. If not enabled, one can still join an AD domain if known by the domain name.

If the appliance has Network Manager disabled, it can be enabled as follows:

# systemctl enable NetworkManager
# systemctl start NetworkManager

Discovering AD Domains

This only works if Network Manager is enabled.

# realm discover
example.com
  type: kerberos
  realm-name: EXAMPLE.COM
  domain-name: example.com
  configured: kerberos-member
  server-software: active-directory
  client-software: sssd
  required-package: oddjob
  required-package: oddjob-mkhomedir
  required-package: sssd
  required-package: adcli
  required-package: samba-common
  login-formats: %U@example.com
  login-policy: allow-realm-logins

Joining AD Domain

When joining an AD domain, specify a user that has enough permission to be able to browse the directory.

# realm join example.com -U user
Password for user: xxxxxxxx
#

Allowing AD Users to Login

# realm permit --all

Configure SSSD

Update the /etc/sssd/sssd.conf file as follows:

Note: Starting with SSSD version 1.15.2, which will be available in CentOS version 7.4, SSSD will provide the domain name as a user attribute. The below examples show how to set ldap_user_extra_attrs and user_attributes to take advantage of this new feature. If running an appliance built with CentOS version prior to CentOS 7.4 do not include domainname for these attributes.

    [domain/example.com]
    ad_domain = example.com
    krb5_realm = EXAMPLE.COM
    realmd_tags = manages-system joined-with-samba
    cache_credentials = True
    id_provider = ad
    krb5_store_password_if_offline = True
    default_shell = /bin/bash
    ldap_id_mapping = True
    use_fully_qualified_names = True
    fallback_homedir = /home/%d/%u
    access_provider = ad
=>  ad_gpo_map_permit = +httpd-auth
=>  ldap_user_extra_attrs = mail, givenname, sn, displayname, domainname

=>  [sssd]
=>  domains = example.com
=>  config_file_version = 2
=>  services = nss, pam, ifp
=>  default_domain_suffix = example.com

=>  [nss]
=>  homedir_substring = /home

=>  [pam]
=>  default_domain_suffix = example.com

=>  [ifp]
=>  default_domain_suffix = example.com
=>  allowed_uids = apache, root, manageiq
=>  user_attributes = +mail, +givenname, +sn, +displayname, +domainname

Configure Apache

Make sure the Kerberos keytab created by realm join above is readable by Apache.

# chgrp apache /etc/krb5.keytab
# chmod 640    /etc/krb5.keytab

Create the Apache configuration files

# TEMPLATE_DIR="/opt/manageiq/manageiq-appliance/TEMPLATE"
# cp ${TEMPLATE_DIR}/etc/pam.d/httpd-auth                         \
                    /etc/pam.d/httpd-auth
# cp ${TEMPLATE_DIR}/etc/httpd/conf.d/manageiq-remote-user.conf       \
                    /etc/httpd/conf.d/
# cp ${TEMPLATE_DIR}/etc/httpd/conf.d/manageiq-external-auth.conf.erb \
                    /etc/httpd/conf.d/manageiq-external-auth.conf

Update the Apache configuration file /etc/httpd/conf.d/manageiq-external-auth.conf as follows to reference the Kerberos keytab appropriately.

...
    <Location /dashboard/kerberos_authenticate>
      AuthType           GSSAPI
      AuthName           "GSSAPI Single Sign On Login"
=>    GssapiCredStore    keytab:/etc/krb5.keytab
      GssapiLocalName    on
      Require            pam-account httpd-auth

      ErrorDocument 401 /proxy_pages/invalid_sso_credentials.js
    </Location>

...

Set appropriate SELinux permissions:

# setsebool -P allow_httpd_mod_auth_pam on
# setsebool -P httpd_dbus_sssd          on

Restart Services

# systemctl restart sssd
# systemctl restart httpd

Configure Administrative UI

Login as admin, then in Configure→Configuration→Authentication

  • Set mode to External (httpd)

  • Check: Get User Groups from External Authentication (httpd)

  • Check: Enable Single Signon if you want to allow Kerberos SSO to AD.

  • Click Save.

The above steps need to be done on each UI and WebService enabled appliance.

in Configure→Configuration→Access Control

  • Make sure the user’s AD group for the appliance are created and appropriate roles assigned to those groups.