Chapter 7. Introduction to RHEL system roles By using RHEL system roles, you can remotely manage the system configurations of multiple RHEL systems across major versions of RHEL. Important terms and concepts The following describes important terms and concepts in an Ansible environment: Control node A control node is the system from which you run Ansible commands and playbooks. Your control node can be an Ansible Automation Platform, Red Hat Satellite, or a RHEL 9, 8, or 7 host. For more information, see Preparing a control node on RHEL 9 . Managed node Managed nodes are the servers and network devices that you manage with Ansible. Managed nodes are also sometimes called hosts. Ansible does not have to be installed on managed nodes. For more information, see Preparing a managed node . Ansible playbook In a playbook, you define the configuration you want to achieve on your managed nodes or a set of steps for the system on the managed node to perform. Playbooks are Ansible's configuration, deployment, and orchestration language. Inventory In an inventory file, you list the managed nodes and specify information such as IP address for each managed node. In the inventory, you can also organize the managed nodes by creating and nesting groups for easier scaling. An inventory file is also sometimes called a hostfile. Available roles on a Red Hat Enterprise Linux 9 control node On a Red Hat Enterprise Linux 9 control node, the rhel-system-roles package provides the following roles: Role name Role description Chapter title certificate Certificate Issuance and Renewal Requesting certificates by using RHEL system roles cockpit Web console Installing and configuring web console with the cockpit RHEL system role crypto_policies System-wide cryptographic policies Setting a custom cryptographic policy across systems firewall Firewalld Configuring firewalld by using system roles ha_cluster HA Cluster Configuring a high-availability cluster by using system roles kdump Kernel Dumps Configuring kdump by using RHEL system roles kernel_settings Kernel Settings Using Ansible roles to permanently configure kernel parameters logging Logging Using the logging system role metrics Metrics (PCP) Monitoring performance by using RHEL system roles network Networking Using the network RHEL system role to manage InfiniBand connections nbde_client Network Bound Disk Encryption client Using the nbde_client and nbde_server system roles nbde_server Network Bound Disk Encryption server Using the nbde_client and nbde_server system roles postfix Postfix Variables of the postfix role in system roles postgresql PostgreSQL Installing and configuring PostgreSQL by using the postgresql RHEL system role selinux SELinux Configuring SELinux by using system roles ssh SSH client Configuring secure communication with the ssh system roles sshd SSH server Configuring secure communication with the ssh system roles storage Storage Managing local storage by using RHEL system roles tlog Terminal Session Recording Configuring a system for session recording by using the tlog RHEL system role timesync Time Synchronization Configuring time synchronization by using RHEL system roles vpn VPN Configuring VPN connections with IPsec by using the vpn RHEL system role Additional resources Automating system administration by using RHEL system roles Red Hat Enterprise Linux (RHEL) system roles /usr/share/ansible/roles/rhel-system-roles. <role_name> /README.md file /usr/share/doc/rhel-system-roles/ <role_name> / directory

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