Chapter 34. Using Ansible to configure HBAC and sudo rules in IdM Using host-based access control (HBAC) in Identity Management (IdM), you can define policies that restrict access to hosts or services based on the following: The user attempting to log in and this user's groups The host that a user is trying to access and the host groups to which that host belongs The service that is being used to access a host Using sudo , a user can run programs as another user, with different privileges, for example root privileges. In IdM, you can manage sudo rules centrally. You can define sudo rules based on user groups, host groups and command groups, as well as individual users, hosts and commands. Complete this procedure to ensure the presence of the following HBAC and sudo rules for IdM users: jane can only access host client01.idm.example.com . john can only access host client02.idm.example.com . Members of the admins group, which includes the default admin user as well as the regular alice user, can access any IdM host. Members of the admins group can run sudo with the following commands on any IdM host: /usr/sbin/reboot /usr/bin/less /usr/sbin/setenforce The following diagram represents the desired configuration described above: Figure 34.1. IdM HBAC and SUDO rules diagram Prerequisites On the control node: You are using Ansible version 2.14 or later. You have installed the ansible-freeipa package. You have created an Ansible inventory file with the fully-qualified domain name (FQDN) of the IdM server in the ~/ MyPlaybooks / directory. You have stored your ipaadmin_password in the secret.yml Ansible vault. The users jane , john and alice exist in IdM. Passwords are configured for these accounts. Procedure Create your Ansible playbook file add-hbac-and-sudo-rules-to-idm.yml with the following content: Run the playbook: Verification Connect to client01 as the jane user: The output verifies that jane has logged in to client01. Try to connect to client02 as the jane user: The output verifies that jane cannot log in to client02. Connect to client02 as the alice user: The output verifies that alice has logged in to client02. Try to view the contents of the /etc/sssd/sssd.conf file using less without invoking the superuser privileges: The attempt fails as the file is not readable by anyone except the owner of the file, which is root . Invoke the root privileges to view the contents of the /etc/sssd/sssd.conf file using less : The output verifies that alice can execute the less command on the /etc/sssd/sssd.conf file. Additional resources Host-based access control rules in IdM Sudo access on an IdM client

Commands:
--- - name: Playbook to manage IPA HBAC and SUDO rules hosts: ipaserver become: false gather_facts: false vars_files: - /home/<user_name>/MyPlaybooks/secret.yml module_defaults: ipahbacrule: ipaadmin_password: "{{ ipaadmin_password }}" ipagroup: ipaadmin_password: "{{ ipaadmin_password }}" ipasudocmd: ipaadmin_password: "{{ ipaadmin_password }}" ipasudocmdgroup: ipaadmin_password: "{{ ipaadmin_password }}" ipasudorule: ipaadmin_password: "{{ ipaadmin_password }}" tasks: - name: HBAC Rule for Jane - can log in to client01 ipahbacrule: # Creates the rule name: Jane_rule hbacsvc: - sshd - login host: # Host name - client01.idm.example.com user: - jane - name: HBAC Rule for John - can log in to client02 ipahbacrule: # Creates the rule name: john_rule hbacsvc: - sshd - login host: # Host name - client02.idm.example.com user: - john - name: Add user member alice to group admins ipagroup: name: admins action: member user: - alice - name: HBAC Rule for IdM administrators ipahbacrule: # Rule to allow admins full access name: admin_access # Rule name servicecat: all # All services hostcat: all # All hosts group: # User group - admins - name: Add reboot command to SUDO ipasudocmd: name: /usr/sbin/reboot state: present - name: Add less command to SUDO ipasudocmd: name: /usr/bin/less state: present - name: Add setenforce command to SUDO ipasudocmd: name: /usr/sbin/setenforce state: present - name: Create a SUDO command group ipasudocmdgroup: name: cmd_grp_1 description: "Group of important commands" sudocmd: - /usr/sbin/setenforce - /usr/bin/less - /usr/sbin/reboot action: sudocmdgroup state: present - name: Create a SUDO rule with a SUDO command group ipasudorule: name: sudo_rule_1 allow_sudocmdgroup: - cmd_grp_1 group: admins state: present - name: Disable allow_all HBAC Rule ipahbacrule: # Rule to allow admins full access name: allow_all # Rule name state: disabled # Disables rule to allow everyone the ability to login
ansible-playbook --vault-password-file=password_file -i inventory add-hbac-and-sudo-rules-to-idm.yml
~]USD ssh jane@client01 Password: Last login: Fri Aug 11 15:32:18 2023 from 192.168.122.1 [jane@client01 ~]USD
~]USD ssh jane@client02 Password: Connection closed by 192.168.122.47 port 22
~]USD ssh alice@client02 Password: Last login: Fri Aug 10 16:13:43 2023 from 192.168.122.1
[alice@client02 ~]USD less /etc/sssd/sssd.conf /etc/sssd/sssd.conf: Permission denied
[alice@client02 ~]USD sudo less /etc/sssd/sssd.conf [sudo] password for alice: [domain/idm.example.com] id_provider = ipa ipa_server_mode = True [...]