Docker with Oracle database: install patches automatically

Recently I had to install the patch for fixing cross-platform PDB transport bug onto the docker images with Oracle, so these are easy way how to do it:

1. create directory “patches” and create “”:


unzip  -u ./*.zip

for D in *; do
    if [ -d "${D}" ]; then
        echo =================================================
        echo " *** Processing patch # ${D}... "   # your processing here
        cd "${D}"
        opatch apply -silent
    cd  (more...)

From locally running Node application to Cloud based Kubernetes Deployment

In this article I will discuss the steps I had to go through in order to take my locally running Node application – with various hard coded and sometimes secret values – and deploy it on a cloud based Kubernetes cluster.  I will discuss the containerization of the application, the replacement of hard coded values with references to environment variables, the Docker container image manipulation, the creation of the Kubernetes yaml files for creating (more...)

Docker summary

Today just a summary posting of all my docker activities:

Monitoring Spring Boot applications with Prometheus and Grafana

In order to compare the performance of different JDKs for reactive Spring Boot services, I made a setup in which a Spring Boot application is wrapped in a Docker container. This makes it easy to create different containers for different JDKs with the same Spring Boot application running in it. The Spring Boot application exposes metrics to Prometheus. Grafana can read these metrics and allows to make nice visualizations from it. This blog post describes (more...)

Running Reactive Spring Boot on GraalVM in Docker

GraalVM is an open source polyglot VM which makes it easy to mix and match different languages such as Java, Javascript and R. It has the ability (with some restrictions) to compile code to native executables. This of course offers great performance benefits. Recently, GraalVM Docker files and images have become available. See here.

Since Spring Boot is a popular Java framework and reactive (non blocking) RESTful services/clients implemented in Spring Boot are also interesting (more...)

Quick Start with Eclipse Che – Browser based IDE, running on Docker

One of the nice discoveries I made last week during CodeOne 2018 was Eclipse Che. This is a browser based polyglot IDE that runs in a Docker container – either locally, on a central server or in the cloud, on a stand alone Docker engine, a Kubernetes or an OpenShift cluster. Running Eclipse Che is quite easy, upgrading and removing Eclipse Che is just as easy. Working in a browser based IDE does not have (more...)

How to use node-red to interact with twitter

Recently I had to setup an application that was able to read twitter and, based on some predefined keywords,  had to reply to specific tweets. I decided to have a look at node-red to set this stuff up. It proofed to be rather straightforward and easy to implement. The hardest part was to get approval for a twitter developer account. In this post I describe how I used node-red and how I

Docker on Oracle Linux

It occurred to me that if you want to start using Docker there are plenty examples that use Ubuntu as a base platform. I read a book called Learning Docker that assumes Ubuntu for the examples. I know I am quite stubborn, a "know-it-better" person, but I want to be able to do the same on Oracle Linux.

Docker on Oracle Linux turns out not too complicated. But I ran in to a caveat that (more...)

Could RedHat’s absolute commitment to OpenShift put them into difficult waters?

As a middleware (to use a fading term) or technical architect, I preferred not to get too involved in the detailed OS layer considerations when it can be helped (my Infrastructure Architect colleagues will always know more about NICs, port bonding, kernel versions etc etc than I ever will) and why I prefer to work with PaaS over IaaS.

But there is an undeniable trend where having a greater understanding of the OS is necessary, (more...)

Setting up Docker on Oracle Linux 7

Docker has become widely popular in the last couple of years. I use it on a regular basis these days for running Oracle databases on my laptop. Docker is available on all popular Linux distributions, as well as Mac and Windows, and of course Oracle Linux is no exception. Since a long time Docker ships … Continue reading "Setting up Docker on Oracle Linux 7"

Docker: Networking with docker swarm: creating new subnets/gateways/…

In this posting i explained how to configure the network for a container on a docker machine.
If you want to do this for a docker swarm, you have to change the commands. The network driver "bridge" does not work in swarm mode:
(How to run a container inside a swarm take a look here)

docker service create  --network mybrigde --name helloworld alpine ping

Error: No such network: mybrigde
Even (more...)

Docker: Network configuration: How to customize the network bridge and use my own subnet / netmask / CiDR

In my last posting i described how to configure the network settings of a container via docker command line:
--net none
--net bridge
Now i want to try to change the subnet from the standard to another ip range.

There are some tutorials out there which say:

docker run -it  --net bridge  --fixed-cidr ""  alpine /bin/ash
unknown flag: --fixed-cidr
but this doesa not work any more.

First you (more...)

Docker: Network configuration – none / brigde / hostname / dns entries

If you are starting your docker container you can add some network configuration details via command line.
Let's start with the easiest network setting:
docker run -it  --net none alpine /bin/ash
This setting starts the container without any connectivity to the network:
# ip addr show
1: lo: mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet scope host lo
       valid_lft forever preferred_lft forever

Docker: How to limit memory

By starting your container you can limit the RAM usage simply by adding
-m 4M

(this limits the memory to 4 megabytes).

To check this simply run:

docker run -it -m=4M  --rm alpine /bin/ash

and on your docker machine check the following entry:

alpine:~# cat /sys/fs/cgroup/memory/docker/4ce0403caf667e7a6d446eac3820373aefafe4e73463357f680d7b38a392ba62/memory.limit_in_bytes 

Docker: Lessons learned – Logging

After some time working with docker here my experiences:

Some days ago i created my own container with a minimal web service.

Here the
sed -i  's/Hostname:.*/Hostname: '$HOSTNAME'/g' index.html
while true; do { echo -e 'HTTP/1.1 200 OK\r\n'; cat index.html;}  | nc  -l -p 8080  2>&1 >> logfile; done
This is the Dockerfile:
FROM alpine


RUN mkdir ncweb

ADD .  /tmp

ENTRYPOINT [ "/tmp/" (more...)

ADF on Docker – Java Memory Limit Tuning for JVM

It might look like a challenge to run Java in Docker environment, by default Java is not aware of Docker memory limits. Check this article for example - Java inside docker: What you must know to not FAIL.  I was able to run WebLogic and ADF (Essential WebLogic Tuning to Run on Docker and Avoid OOM) on Docker previously without Java memory issues, using JAVA_OPTIONS=-XX:+UnlockCommercialFeatures -XX:+ResourceManagement -XX:+UseG1GC. However after Docker upgrade (more...)

Docker Oracle and local installs

| Mar 14, 2018
So you want Docker and to install and Oracle Database locally.  So did I and while I have VirtualBox and the Oracle Developer Day VM, I wanted to setup docker and the Oracle Database
Well Colm Divilly (@cdivilly) has cleared it up for me.  His Gist on on Github had me up and running. Very little work on my part here, following Colm's detailed instructions, (barring time for downloads) I had docker (more...)

Get going with Project Fn on a remote Kubernetes Cluster from a Windows laptop–using Vagrant, VirtualBox, Docker, Helm and kubectl

| Mar 4, 2018


The challenge I describe in this article is quite specific. I have a Windows laptop. I have access to a remote Kubernetes cluster (on Oracle Cloud Infrastructure). I want to create Fn functions and deploy them to an Fn server running on that Kubernetes (k8s from now on) environment and I want to be able to execute functions running on k8s from my laptop. That’s it.

In this article I will take you on a (more…)

Using SQL*Plus to Seed your Dockerized Oracle Database

In my last blog, you learned  to create a containerized Oracle database for your development/testing purpose. You also know how to connect to your container and run command in the container.

Most applications require some reference data e.g. example,my  OrderApp application based on Apache Tom EE  requires catalog data to be pre-populated before I can test my application. 

One of the readers asked me how can we run a SQL (more...)

Dockerizing Your Development and Test Oracle databases

You are probably reading this blog because your application depends on Oracle database. Most enterprises in the world depend on Oracle database to run their business. If you are a developer using Oracle database and getting started with Docker, you must be wondering how can you use a containerized Oracle database. 

In my last blog, I outlined how you can use a Dockerized Tomcat /Tom EE with an Oracle database. In this blog, (more...)