Thoughts on Performance Tuning

Tuning an application for performance is like finding a needle in a haystack. If someone asks you “Is my web server parameters correct?” “Is my connection pool settings correct?”, “How do I even know my application needs to be tuned or shall I put more resources?” The correct answer is “I don’t know”. An application does not exist in isolation. ... Read more 20 Mar 2019 - 3 minute read

Howto Install SSL Certificates to your Openshift route

Assumptions You have OpenShift 3.9 or above You are using Openshift on Centos 7 You have shell access and able to install software. You have access to your DNS to add a TXT record Obtain SSL certificat from LetsEncrypt Install certbot using the instructions here: https://certbot.eff.org/lets-encrypt/centosrhel7-other Define t... Read more 22 Nov 2018 - 1 minute read

How to install Wildcard SSL certificates from Letsencrypt to your OpenShift Router

Assumptions You are using Openshift on Centos 7 You have shell access and able to install software. You have access to your DNS to add a TXT record You are using the default HAProxy router of OpenShift. WildCard certificate Install certbot using the instructions here: https://certbot.eff.org/lets-encrypt/centosrhel7-other Let’s ... Read more 22 Nov 2018 - 1 minute read

How to Build s2i images

How to Build s2i images In this HOWTO, we will create an s2i builder image for spring boot. Download the s2i binary curl -L https://github.com/openshift/source-to-image/releases/download/v1.1.10/source-to-image-v1.1.10-27f0729d-linux-amd64.tar.gz -o s2i.tar.gz Clone the s2i project cd $HOME git clone https://github.com/ope... Read more 05 Sep 2018 - 3 minute read

How to build a docker image from a Dockerfile in OpenShift

Suppose you have the following Dockerfile: #==== BEGIN DOCKER FILE FROM centos:latest RUN yum install -y java-1.8.0-openjdk-devel RUN yum install -y unzip RUN adduser tomcat USER tomcat RUN cd /home/tomcat && curl -L http://www-us.apache.org/dist/tomcat/tomcat-9/v9.0.8/bin/apache-tomcat-9.0.8.zip -o apache-tomcat-9.0.8.zip #COPY apache-t... Read more 27 Jul 2018 - less than 1 minute read