Month: November 2023

by

Change Runlevel of Rocky Linux 8 without rebooting

You may use the command “telinit” to change the SysV system runlevel without the need to reboot. You will need root access to run the command

Use 1: Single User Mode

# telinit S

Use 2: To go to Graphical.Target

# telinit 5

Use 3: To go to Multi-User.Target

# telinit 3

Use 4: To Reload daemon configuration. This is equivalent to systemctl daemon-reload.

# telinit q

To verify, you can use the command systemctl get-default

# systemctl get-default
graphical.target
by

Optimizing Firewalld Configuration with Ansible’s with_items Parameter

Ansible is great for configuring host-based firewall like Firewalld. One thing you will note is that we are using with_items parameter a lot and it is very useful in this case since we have a number of parameters within items. 

- name: FirewallD Rules (Ports)
  firewalld:
    permanent: yes
    immediate: yes
    port: "{{item.port}}/{{item.proto}}"
    state: "{{item.state}}"
    zone: "{{item.zone}}"
  with_items:
    - {port: "80", proto: "tcp", state: "enabled", zone: "public" }
    - {port: "80", proto: "udp", state: "enabled", zone: "public" }
    - {port: "443", proto: "tcp", state: "disabled", zone: "public" }
    - {port: "443", proto: "udp", state: "disabled", zone: "public" }


- name: FirewallD Rules (Services)
  firewalld:
    permanent: yes
    immediate: yes
    service: "{{item.service}}"
    state: "{{item.state}}"
    zone: "{{item.zone}}"
  with_items:
    - {service: "cockpit", state: "disabled", zone: "public" }

- name: Turn on Firewalld.service on Compute Nodes
  systemd:
    name: firewalld
    state: started
    enabled: yes
  when:
    - ansible_os_family == "RedHat"
    - ansible_distribution_major_version == "8"

References:

by

Updating ANSYS 2023R2 License Server Information for Linux Client using the command line

If you are updating ANSYS License Server Information for ANSYS Client using only the command line, do the following

# vim usr/local/ansys_inc/shared_files/licensing/ansyslmd.ini
SERVER=1055@IP_Address_Of_ANSYS_LIC_SVR
ANSYSLI_SERVERS=2325@IP_Address_Of_ANSYS_LIC_SVR

Make sure the 1055, 1056, 2325 Ports of the License Server are opened.

by

Enterprise Container Management Solutions – SuSE Rancher

What is SuSE Rancher?

Website: https://www.rancher.com/ (by SuSE)

Rancher Labs builds innovative, open source container management solutions for enterprises leveraging containers to accelerate software development and improve IT operations. The flagship product, Rancher, is a complete container management platform that makes it easy to manage all aspects of running containers in development and production environments, on any infrastructure. RancherOS is a minimalist Linux distribution which is perfect for running Docker containers at scale.

View on-demand recordings of past Rancher demos, online meetups, and Kubernetes tutorials at Rancher Youtube Channel. ( Rancher Labs )

This guide walks you through the process of adopting an enterprise container management platform (Dummies e-copy).

This guide will help security teams understand the attack surface for Kubernetes deployments and how attackers can exploit vulnerabilities. Get the e-copy of the Ultimate Guide to Kubernetes Security

by

Could not load the Qt platform plugin “xcb” in “” even though it was found in Rocky Linux 8

I was installing ANSYS 2023 R2 on Rocky Linux 8 and I encoutnered the error

qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: xcb.

Solution

# dnf install python3-qt5
by

Mounting NTFS on Rocky Linux 8

If you are planning to mount like a portable drive using Windows NTFS File System on the Rocky Linux 8, what you will see immediately when you issue the command after you plug the portable drive in

# mount /dev/sdd1 /data1
mount: /data1: unknown filesystem type 'ntfs'.

Step 1: Enable EPEL Repo

# dnf install epel-release

Step 2: Install NTFS-3g

# dnf install ntfs-3g

In some blogs written elsewhere, these 2 packages are more than enough, but I was still having issues. In my situation, I need to put in 5 packages

Step 3: Install all NTFS-3g packages

# dnf install *ntfs*

This time it works for me.

Step 4: Simply mount (Hooray!)

 # mount /dev/sdd1 /data1