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Chapter 9. Configuring SElinux using System Roles

9.1. Introduction to the SELinux System Role

RHEL System Roles is a collection of Ansible roles and modules that provide a consistent configuration interface to remotely manage multiple RHEL systems. The SELinux System Role enables the following actions:

  • Cleaning local policy modifications related to SELinux booleans, file contexts, ports, and logins.
  • Setting SELinux policy booleans, file contexts, ports, and logins.
  • Restoring file contexts on specified files or directories.
  • Managing SELinux modules.

The following table provides an overview of input variables available in the SELinux System Role.

Table 9.1. SELinux System Role variables

Role variableDescriptionCLI alternative

selinux_policy

Chooses a policy protecting targeted processes or Multi Level Security protection.

SELINUXTYPE in /etc/selinux/config

selinux_state

Switches SELinux modes.

setenforce and SELINUX in /etc/selinux/config.

selinux_booleans

Enables and disables SELinux booleans.

setsebool

selinux_fcontexts

Adds or removes a SELinux file context mapping.

semanage fcontext

selinux_restore_dirs

Restores SELinux labels in the file-system tree.

restorecon -R

selinux_ports

Sets SELinux labels on ports.

semanage port

selinux_logins

Sets users to SELinux user mapping.

semanage login

selinux_modules

Installs, enables, disables, or removes SELinux modules.

semodule

The /usr/share/doc/rhel-system-roles/selinux/example-selinux-playbook.yml example playbook installed by the rhel-system-roles package demonstrates how to set the targeted policy in enforcing mode. The playbook also applies several local policy modifications and restores file contexts in the /tmp/test_dir/ directory.

For a detailed reference on SELinux role variables, install the rhel-system-roles package, and see the README.md or README.html files in the /usr/share/doc/rhel-system-roles/selinux/ directory.

Additional resources

9.2. Using the SELinux System Role to apply SELinux settings on multiple systems

Follow the steps to prepare and apply an Ansible playbook with your verified SELinux settings.

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the SELinux System Role.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core and rhel-system-roles packages are installed.
    • An inventory file which lists the managed nodes.
Important

RHEL 8.0-8.5 provided access to a separate Ansible repository that contains Ansible Engine 2.9 for automation based on Ansible. Ansible Engine contains command-line utilities such as ansible, ansible-playbook, connectors such as docker and podman, and many plugins and modules. For information on how to obtain and install Ansible Engine, see the How to download and install Red Hat Ansible Engine Knowledgebase article.

RHEL 8.6 and 9.0 have introduced Ansible Core (provided as the ansible-core package), which contains the Ansible command-line utilities, commands, and a small set of built-in Ansible plugins. RHEL provides this package through the AppStream repository, and it has a limited scope of support. For more information, see the Scope of support for the Ansible Core package included in the RHEL 9 and RHEL 8.6 and later AppStream repositories Knowledgebase article.

  • An inventory file which lists the managed nodes.

Procedure

  1. Prepare your playbook. You can either start from the scratch or modify the example playbook installed as a part of the rhel-system-roles package:

    # cp /usr/share/doc/rhel-system-roles/selinux/example-selinux-playbook.yml my-selinux-playbook.yml
    # vi my-selinux-playbook.yml
  2. Change the content of the playbook to fit your scenario. For example, the following part ensures that the system installs and enables the selinux-local-1.pp SELinux module:

    selinux_modules:
    - { path: "selinux-local-1.pp", priority: "400" }
  3. Save the changes, and exit the text editor.
  4. Run your playbook on the host1, host2, and host3 systems:

    # ansible-playbook -i host1,host2,host3 my-selinux-playbook.yml

Additional resources

  • For more information, install the rhel-system-roles package, and see the /usr/share/doc/rhel-system-roles/selinux/ and /usr/share/ansible/roles/rhel-system-roles.selinux/ directories.