Imagine a scenario where you have a monolithic application which uses a config file to store information about log directories, cert dirs and other service information. As an example to it following config file (- it is taken and modified from Haaukins project which I work on- ) can be considered:

In this config file we have some set of keys which are defined to be used inside the application, however let’s say we would like to update some values from the config file. Then in normal cases (-if no hot reload kind of function implemented- ), user needs…

Build custom AMI on AWS


In this blog post, provisioning and customizing images using packer will be shown with a template repository.

If you are asking or wondering what is Packer, the official definition is :

Packer is a free and open source tool for creating golden images for multiple platforms from a single source configuration. (From Official Website).

This post includes provisioning of ubuntu image on AWS and local.

In an ideal repository of Packer template, it would be nice to have a skeleton where it includes uploads, http, scripts folders along packer configuration file with…

In this post, deployment process of an application with Ansible will be explained. Traditionally applications can be deployed in different ways, quite similar approach to deploy applications like in Ansible is executing bash script which has ssh commands. To give an example, Travis continuous integration has a feature where a bash script can be defined to deploy application and through given instructions within bash script, application can be successfully deployed.

Details regarding to deployment using Travis bash scripting can be found here

Travis Script Deployment

I would like to give an real case example from one of the project which I work on…

In this post, I will be describing to setup a workflow to build and release your Latex files through Github actions. First of all, keep in mind that this post is not about what is Latex and how to use it.

It is extremely nice to integrate daily development tools such as CI/CD to your preparation of paper, without any hassle. Why is that because it is cool to track of what has been changed on a paper over time. In fact, having a couple of people who are responsible in different parts of paper, sometimes blocks others. Therefore, having…

In this post, I am going to write demo for a tool which I have just met, it is called Evans. It is basically universal gRPC client. What it means ? Basically when you have gRPC server and would like to test gRPC calls without creating client, you can test server side calls with Evans. It is known that gRPC is very common communication method between microservices, it can be used for internal and external communication. I do not have intention to explain what gRPC is in this post since it is not the purpose. …

Originally posted at

In recent post, which is Setup Highly Available Kubernetes Cluster with HAProxy a highly available Kubernetes cluster is created. However, once I started to dig in and deploy some stuff to cluster, I realized that I am not able to connect any deployed application or services. For instance, when an web application is deployed using HAProxy load balancer (endpoint), and check from kubectl (on client side), its status is running. However, that application could not be reached from outside world although I re-patch an external IP address by following command

$ kubectl patch svc <application-name> -n…

Originally posted at

The main purpose of this blog post a simple walk through of setting up Kubernetes cluster with external HAProxy which will be the endpoint where our kubectl client communicates over. Node specifications for this setup is given as shown in the table below. Keep in mind that all of them has access to each other with password and without password. The environment which Kubernetes cluster will stay is running on OpenStack. It means that once a configuration (ssh keys, hosts, and etc) is done for example master1 then all other nodes could be initialized through snapshot…

Bugün sizlere kendinize ait VPN sistemi nasıl kurulur, onu anlatmak istiyorum, daha önce İngilizce olarak, yayınladım fakat Türkçe bir kaynağın da faydalı olabileceğini düşündüm. Burada anlatılanlar, ubuntu ailesine (16.04,18.04) ait sunucular üzerinde test edilmiştir.

İlk olarak bulut hizmeti sağlayan bir şirketten bu DigitalOcean, Google Cloud, Microsoft Azure veya Amazon olabilir, sunucu kiralıyorsunuz, en ucuzu ve makul olanı DigitalOcean tarafından sunulan aylık 5 dolar olan sunucu diyebilirim. Sunucuyu kiraladıktan ve ssh bağlantısını sağladıktan sonra VPN kurulumuna geçebiliriz.

VPN hakkında tam bilgisi olmayan arkadaşlar için şu şekilde özetlenebilir, sizin için oluşturulmuş sanal bir bağlantı noktası gibi düşünebilirsiniz. Yani VPN’e bağlandıktan sonra bilgisayarınızdan…

Ahmet Türkmen

Software Engineer at Aalborg University, Denmark

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