kubernetes

OpenShift Cluster Metrics and Cassandra Troubleshooting

November 14, 2016

OpenShift gathers cluster metrics such as CPU, memory, and network bandwidth per pod which can assist in troubleshooting and capacity planning. The metrics are also used to support horizontal pod autoscaling, which makes the metrics service not just helpful, but critical to operation. Missing Liveness Probes There are 3 major components in the metrics collection process. Heapster gathers stats from Docker and feeds them to Hawkular Metrics to tuck away for safe keeping in Cassandra.

Deploy Hawkular Metrics in CDK 2.1 OpenShift 3.2

June 16, 2016

Update! I failed with CDK 2.0, but CDK 2.1 works with some fiddling. In my last post I installed Red Hat Container Developer Kit to deploy OpenShift Enterprise using Vagrant. But now I want to add Hawkular Metrics to that deployment. Deploy Metrics Refer to the docs for deploying metrics in OSE. Login to the vagrant CDK VM before continuing $ cd ~/cdk/components/rhel/rhel-ose/ $ vagrant ssh $ oc login Authentication required for https://127.

Getting Started With RedHat Container Development Kit

June 16, 2016

The RedHat Container Developer Kit allows you to deploy OpenShift on your laptop for easier testing and development. Here is how to deploy it. Register as a RedHat Developer Obtain a RH login Place credentials in ~/.vagrant.d/Vagrantfile to enable updates for VMs by automatically registering with RedHat Subscription Manager Vagrant.configure('2') do |config| config.registration.username = '<your Red Hat username>' config.registration.password = '<your Red Hat password>' end Mac OS X Prereqs Install pre-reqs:

Upgrading OpenShift Enterprise from 3.1 to 3.2

May 17, 2016

Upgrading from OSE 3.1 to 3.2 using the playbook went quite well for me, but there were a few issues to sort out. The issues were related to: ip failover had to be updated manually there was about 5 minutes downtime during the upgrade updates to image streams docker error messages updated policy and role bindings build strategy Source is not allowed hawkular metrics Upgrade Process Following the directions is pretty straight forward.

Changing the SSL Certificate for OpenShift Console

March 24, 2016

OpenShift has an internal CA for generating certificates to authenticate intra-cluster communication, but your browser doesn’t trust this CA. Perhaps you want to fix that without mucking with the internal SSL communication? I did. Here is how. This OpenShift doc explains how to do this, but it isn’t very clear, to me at least. Overview An outline of the steps: Only make changes to the public URLs and not any internal URLs.

OpenShift High Availability - Routing

March 1, 2016

Highly availabile containers in OpenShift are baked into the cake thanks to replication controllers and service load balancing, but there are plenty of other single points of failure. Here is how to eliminate many of those. Single Points of Failure The components of OpenShift include: Master controller manager server and API endpoint Etcd configuration and state storage Docker Registry Router haproxy This post is mostly about adding high availability to the routing layer.