Skip to main content

Managing Kubernetes Cluster in Ubuntu

There are several tools and services in the market that we can use to deploy and manage Kubernetes clusters. Some tools allow us to self-manage the cluster without charge, some require us to subscribe for the license, and some services are provided as a Kubernetes as a Service such as Amazon EKS and Red Hat OpenShift Dedicated. For development purposes or small-scale service, there is a free tool to manage Kubernetes clusters named minikube which is available for Windows, Linux, and MacOS.

To build the cluster, Minikube supports several virtualization technologies such as Hypervisor, KVM, Docker, and so on. In this writing, we will try to utilize Docker as the virtualization solution and run it in Ubuntu 22.04. In general, we will run through the following steps.

  1. Install Minikube
  2. Install Docker
  3. Allow a non-root user to access Docker
  4. Start Minikube
  5. Enable Ingress extension
  6. Install Kubectl

Install Minikube

First, we need to install Minikube's dependencies and then download the binary to our machine.

sudo apt install -y curl wget apt-transport-https
wget https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64

Then, we can store the executable file in the appropriate directory for binary files.

sudo cp minikube-linux-amd64 /usr/local/bin/minikube
sudo chmod +x /usr/local/bin/minikube
minikube version

Before we can start the Minikube, we need a virtualization tool in our machine, in this case, we utilize Docker.


Install Docker

We can follow the installation instructions available on the Docker website HERE.


Allow a non-root user to access Docker

This step is necessary because Minikube requires a non-root user to start the service while Docker needs otherwise. We can add an existing user to the docker group.

sudo usermod -aG docker $USER

After running the above command, we need to leave the current user session and then re-enter the session to apply the change.


Start Minikube

Minikube will find the available driver automatically. Because we only have Docker in our machine, Minikube will use Docker by default.

minikube start

Enable Ingress extension

Ingress extension is useful to allow Minikube to direct requests into the Kubernetes cluster. Our machine will have an additional network driver with a specific IP that can be accessed by other services in our machine to go into the Kubernetes cluster.

minikube addons enable ingress
minikube ip

Install Kubectl

This tool is used to control and interact with the clusters. In Ubuntu, this tool is available in the package manager. For installing this tool, we can follow the instructions provided on the Kubernetes.io website HERE.


Comments

Popular posts from this blog

Configuring Swap Memory on Ubuntu Using Ansible

If we maintain a Linux machine with a low memory capacity while we are required to run an application with high memory consumption, enabling swap memory is an option. Ansible can be utilized as a helper tool to automate the creation of swap memory. A swap file can be allocated in the available storage of the machine. The swap file then can be assigned as a swap memory. Firstly, we should prepare the inventory file. The following snippet is an example, you must provide your own configuration. [server] 192.168.1.2 [server:vars] ansible_user=root ansible_ssh_private_key_file=~/.ssh/id_rsa Secondly, we need to prepare the task file that contains not only the tasks but also some variables and connection information. For instance, we set /swapfile  as the name of our swap file. We also set the swap memory size to 2GB and the swappiness level to 60. - hosts: server become: true vars: swap_vars: size: 2G swappiness: 60 For simplicity, we only check the exi

Master Slave Replication to Automatically Backup Your MySQL Database

We can make backup for some databases by periodically running a kind of dump query, like mysqldump in MySQL. That's the simplest method but it can drain our server resources and it's not suitable for large databases. MySQL comes up with master-slave features that allow you to replicate your database to another location (slave). This mechanism enables MySQL to generate a log file which records any action performed to the database. Then, that action will be run in slave database too. For example, we have two database servers with IP address 192.168.0.1 (Master) and 192.168.0.2 (Slave). 1) Configure my.cnf in master server # Master Settings # locate where the changes record will be stored log-bin = /var/log/mysql/mysql-bin.log # set unique ID for master database in master-slave network (up to you) server-id = 111 innodb_flush_log_at_trx_commit = 1 sync_binlog = 1 # select database which will be replicated # by default system will log all databases binlog-do-db =

Installing VSCode Server Manually on Ubuntu

I've ever gotten stuck on updating the VSCode server on my remote server because of an unstable connection between my remote server and visualstudio.com that host the updated server source codes. The download and update process failed over and over so I couldn't remotely access my remote files through VSCode. The solution is by downloading the server source codes through a host with a stable connection which in my case I downloaded from a cloud VPS server. Then I transfer the downloaded source codes as a compressed file to my remote server through SCP. Once the file had been on my remote sever, I extracted them and align the configuration. The more detailed steps are as follows. First, we should get the commit ID of our current VSCode application by clicking on the About option on the Help menu. The commit ID is a hexadecimal number like  92da9481c0904c6adfe372c12da3b7748d74bdcb . Then we can download the compressed server source codes as a single file from the host.

Rangkaian Sensor Infrared dengan Photo Dioda

Keunggulan photodioda dibandingkan LDR adalah photodioda lebih tidak rentan terhadap noise karena hanya menerima sinar infrared, sedangkan LDR menerima seluruh cahaya yang ada termasuk infrared. Rangkaian yang akan kita gunakan adalah seperti gambar di bawah ini. Pada saat intensitas Infrared yang diterima Photodiode besar maka tahanan Photodiode menjadi kecil, sedangkan jika intensitas Infrared yang diterima Photodiode kecil maka tahanan yang dimiliki photodiode besar. Jika  tahanan photodiode kecil  maka tegangan  V- akan kecil . Misal tahanan photodiode mengecil menjadi 10kOhm. Maka dengan teorema pembagi tegangan: V- = Rrx/(Rrx + R2) x Vcc V- = 10 / (10+10) x Vcc V- = (1/2) x 5 Volt V- = 2.5 Volt Sedangkan jika  tahanan photodiode besar  maka tegangan  V- akan besar  (mendekati nilai Vcc). Misal tahanan photodiode menjadi 150kOhm. Maka dengan teorema pembagi tegangan: V- = Rrx/(Rrx + R2) x Vcc V- = 150 / (150+10) x Vcc V- = (150/160) x 5

Resize VirtualBox LVM Storage

VirtualBox is a free solution to host virtual machines on your computer. It provides configuration options for many components on our machine such as memory, storage, networking, etc. It also allows us to resize our machine storage after its operating system is installed. LVM is a volume manager in a Linux platform that helps us to allocate partitions in the system and configure the storage size that will be utilized for a specific volume group. There are some points to be noticed when we work with LVM on VirtualBox to resize our storage. These are some steps that need to be performed. 1. Stop your machine before resizing the storage. 2. Set new storage size using GUI by selecting " File > Virtual Media Manager > Properties " then find the desired virtual hard disk name that will be resized. OR , by running a CLI program located in " Program Files\Oracle\VirtualBox\VBoxManage.exe ".  cd "/c/Program Files/Oracle/VirtualBox" ./VBoxManage.exe list

Setting Up Next.js Project With ESLint, Typescript, and AirBnB Configuration

If we initiate a Next.js project using the  create-next-app tool, our project will be included with ESLint configuration that we can apply using yarn run lint . By default, the tool installs eslint-config-next and extends next/core-web-vitals in the ESLint configuration. The Next.js configuration has been integrated with linting rules for React and several other libraries and tools. yarn create next-app --typescript For additional configuration such as AirBnB, it is also possible. First, we need to install the peer dependencies of eslint-config-airbnb . We also add support for Typescript using eslint-config-airbnb-typescript . yarn add --dev eslint-config-airbnb eslint-plugin-import eslint-plugin-jsx-a11y eslint-plugin-react eslint-plugin-react-hooks yarn add --dev eslint-config-airbnb-typescript @typescript-eslint/eslint-plugin @typescript-eslint/parser After that, we can update the .eslintrc.json file for the new configuration. { "extends": [ "airb