Latest Posts

• Configuring systemd-resolved to Work with dnsmasq on Ubuntu

  Overview

  While attempting to run the openshift-installer locally using libvirt, I ran into a peculiar problem with NetworkManager’s packaged version of dnsmasq and systemd-resolved. After a good amount of troubleshooting (most of it spent trying to understand the relationship between all three components), I was able to work it out such that I could get the OpenShift installer running on Ubuntu.

• Using IAM Roles for Node Bootstrapping

  Overview

  OpenShift clusters are typically deployed all at once. To scale these up or down, you must re-run the Ansible installer or you must configure the cluster auto-scaler. But what if we wanted to scale nodes up and down without using the auto-scaler? For instance, you know you will require a certain number of pods and a specific amount of compute power, but you want to pre-warm it without having to wait for the auto-scaler to kick in. Or you want to bootstrap new nodes without storing the bootstrap kubeconfig. For this, we can use IAM roles to allow the new compute nodes to connect to the Masters and bootstrap.

• Creating an OpenShift Cluster with Terraform

  Overview

  There are many examples of how to create an OpenShift cluster in AWS. Most of these examples use CloudFormation for orchestrating the creation of infrastructure and deploying the cluster. This post walks through how to do it using Terraform.

• Wait for AutoScaling Groups with Terraform

  When using Terraform, it’s not possible to know when the EC2 instances that are part of an AutoScaling Group are completely ready without using an ELB. And by completely ready, I mean we know the instances have finished running their cloud-init process (AKA userdata). See this Github issue for more details. But if we have access to the instances in the VPC, there’s a workaround!

• Setting Up a Gitlab Runner on OpenShift

  Overview

  As a followup to my previous post, Setting Up a Personal GitLab Runner, we’re going to set up a GitLab runner in OpenShift. No longer will you have to make sure your PC is running to get builds working and executing. As long as you have an account and project on the Red Hat IT Open Platform OpenShift (requires VPN) instance, you can run builds on commit from GitLab. Prerequisites: