Mohammad Ahmad, Author at Red Hat Developer

Mohammad's primary area of interest is open source system development, and draws from several areas in IT to build upon this interest. This include web developement (LAMP), system administration, software automation, infrastructure as code, scripting (bash), containerised services.

Areas of Expertise

Ansible, Openshift, Software Automation

Customizing and tuning the Kuryr SDN for Red Hat OpenShift 3.11 on Red Hat OpenStack 13

By Mohammad Ahmad and Luis Tomas Bolivar October 2, 2020

In a previous article, I showed you how to customize Red Hat OpenShift software-defined networking (SDN) for your organization’s requirements and restrictions. In this article, we’ll look at using the Kuryr SDN instead. Using Kuryr with OpenShift 3.11 on Red Hat OpenStack 13 changes the customization requirements because Kuryr works directly with OpenStack Neutron and Octavia.

Note: This article builds on the discussion and examples from my previous one. I recommend reading the previous one first.

Background

Traditional OpenShift installations leverage openshift-sdn, which is specific to OpenShift. Using openshift-sdn means that your containers run on a network within a network. This setup, known as double encapsulation, introduces an additional layer of complexity, which becomes apparent when troubleshooting network issues. Double encapsulation also affects network performance due to the overhead of running a network within a network.

Continue reading “Customizing and tuning the Kuryr SDN for Red Hat OpenShift 3.11 on Red Hat OpenStack 13”

Testing memory-based horizontal pod autoscaling on OpenShift

By Mohammad Ahmad March 19, 2020June 29, 2020

Red Hat OpenShift offers horizontal pod autoscaling (HPA) primarily for CPUs, but it can also perform memory-based HPA, which is useful for applications that are more memory-intensive than CPU-intensive. In this article, I demonstrate how to use OpenShift’s memory-based horizontal pod autoscaling feature (tech preview) to autoscale your pods if the demands on memory increase. The test performed in this article might not necessarily reflect a real application. The tests only aim to demonstrate memory-based HPA in the simplest way possible.

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How to customize the Red Hat OpenShift 3.11 SDN

By Mohammad Ahmad November 1, 2019July 1, 2020

In this article, I’ll highlight a practical case for customizing the Red Hat OpenShift software-defined network (SDN). To achieve this, I will identify the OpenShift-Ansible inventory parameters that configure different aspects of the OpenShift SDN, specifically the cluster, portal, and docker networks.

Why customize the SDN?

An important question I am often asked is: Why do you need to customize the SDN? Isn’t it completely internal? Users generally assume there is no need to customize the SDN because OpenShift’s SDN has no impact on networks outside the OpenShift cluster; therefore, IP conflicts should not be a concern. However, this is not always the case.

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How to configure LDAP user authentication and RBAC in Red Hat OpenShift 3.11

By Mohammad Ahmad August 2, 2019September 3, 2019

In this article, I demonstrate a systematic method to configure LDAP user and group synchronization in Red Hat OpenShift, as well as OpenShift role-based access control (RBAC) for these LDAP users and groups. Following these steps makes the management of your LDAP users and groups within OpenShift much easier. I achieve this goal by demonstrating:

How to validate your ldap parameters with ldaptool prior to installing OpenShift.
How to enable LDAP authentication in OpenShift for specific LDAP groups and organization units.
The scripts and commands that let you synchronize members of your LDAP groups to OpenShift, which in turn lets you apply custom OpenShift RBAC rules on specific users or groups.

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How to install Red Hat OpenShift 3.11 on OpenStack 13

By Mohammad Ahmad April 9, 2019May 1, 2019

Red Hat OpenShift Container Platform is a platform-as-a-service (PaaS). It orchestrates and manages containerized applications through Kubernetes. Although OpenShift Container Platform supports cloud-native applications, it also supports custom-built applications. OpenShift Container Platform can run on a hybrid cloud configuration providing the flexibility to expand and grow.

Red Hat OpenStack Platform is an infrastructure-as-a-service (IaaS). This means it is a cloud-based platform that provides virtual servers and other resources. Users either manage it through a web-based dashboard, through command-line tools, or through RESTful web services.

If you are considering Red Hat OpenShift Container Platform on OpenStack Platform, there are several advantages, including easily increasing the number of compute nodes and using dynamic storage.

In this article, I will outline the main points required to successfully install Red Hat OpenShift Container Platform on OpenStack Platform. Because my OpenStack knowledge is limited, I reached out to my colleagues for help and will not address too many OpenStack technical details here.

Continue reading “How to install Red Hat OpenShift 3.11 on OpenStack 13”

Red Hat OpenShift 3.11 disconnected installation using Satellite Docker registry

By Mohammad Ahmad April 8, 2019April 3, 2019

In this article, I will discuss the prerequisites and requirements for the successful implementation of Red Hat OpenShift 3.11 disconnected installation using Red Hat Satellite as the local Docker registry, which I have been able to do with the support of my colleagues. I also discuss adjustments that may be required post install.

This work is based on the following references:

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RPM packaging: A simplified guide to creating your first RPM

By Mohammad Ahmad March 18, 2019March 15, 2019

The concept of RPM packaging can be overwhelming for first-timers because of the impression a steep learning curve is involved. In this article, I will demonstrate that building an RPM with minimal knowledge and experience is possible. Note that this article is meant as a starting point, not a complete guide to RPM packaging.

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Blog Articles

Mohammad Ahmad

Consultant, Red Hat