Chapter 34. Using Ansible to configure HBAC and sudo rules in IdM

Procedure

1. Create your Ansible playbook file add-hbac-and-sudo-rules-to-idm.yml with the following content:

   ---
   - 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

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2. Run the playbook:

   $ ansible-playbook --vault-password-file=password_file -i inventory add-hbac-and-sudo-rules-to-idm.yml

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Verification

1. Connect to client01 as the jane user:

   ~]$ ssh jane@client01
   Password:
   
   Last login: Fri Aug 11 15:32:18 2023 from 192.168.122.1
   [jane@client01 ~]$

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   The output verifies that jane has logged in to client01.

2. Try to connect to client02 as the jane user:

   ~]$ ssh jane@client02
   Password:
   Connection closed by 192.168.122.47 port 22

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   The output verifies that jane cannot log in to client02.

3. Connect to client02 as the alice user:

   ~]$ ssh alice@client02
   Password:
   
   Last login: Fri Aug 10 16:13:43 2023 from 192.168.122.1

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   The output verifies that alice has logged in to client02.

4. Try to view the contents of the /etc/sssd/sssd.conf file using less without invoking the superuser privileges:

   [alice@client02 ~]$ less /etc/sssd/sssd.conf
   /etc/sssd/sssd.conf: Permission denied

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   The attempt fails as the file is not readable by anyone except the owner of the file, which is root.

5. Invoke the root privileges to view the contents of the /etc/sssd/sssd.conf file using less:

   [alice@client02 ~]$ sudo less /etc/sssd/sssd.conf
   [sudo] password for alice:
   
   [domain/idm.example.com]
   
   id_provider = ipa
   ipa_server_mode = True
   [...]

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   The output verifies that alice can execute the less command on the /etc/sssd/sssd.conf file.