I have been playing with RaspberryPI for a while. There are several project I tried to do with RaspberryPI. These boards play a significant role in my home lab for different experiments like Docker Private Repository, Media Server, Ad Blocker with pi-hole, Secure Proxy for anonymity, secure network access with VPN, Home Security Camera/Surveillance, Data Collector or scraper etc. But This time, I did buy a “DHT-22” sensor for monitoring room temperature and humidity. Humidity is my main concern and wanted to see how it fluctuates.

So, my main plan was to get a DHT-22 to connect properly

I was trying explore some data in Google Sheet and stumble upon a unique problem. There were several columns and rows of data containing strings. I wanted to count specific string.

I wanted to find out how many “aD” in whole set.

One of the most basic things to do in a Linux Server. We can use just passwd <user> to change the password of a user. But to do that in 100s of server can be a tricky one. Ansible is the savior on that perspective.

I have always worked with Linux Systems and thus Bash was my go to tool for some specific tasks. But now I am much more aware with Python than Bash as it does give me better grasp on things. I am not saying that for server scripting, Bash can not do some tasks. It can be used in a vast area of things to solve. But I am now comfortable with Python more.

Recently, I did stumble upon of a task that was related to comparing two huge CSV files.

I have been trying to manage time to explore InfluxDB for observability. This article is one of many about InfluxDB and Telegraf. I will cover basic installation here.

I am recently playing the role as an SRE and that is why I have to deal with a lot of servers. Not only cloud once or clusters but also bare metals as well as Virtual Machines. For more systematic environment preparation, I have Gitlab pipeline. But for basic tasks like change the config on demand or check a specific directory or search something or any other unpredictable or repeated tasks, I need Ansible for better grasp from my local machine or Bastion server. So, what do I have to do?

• Create an entry to the .ssh/config file
• Create an entry ansible host file as inventory

Repeated tasks? For me, yes. I needed to manage these. So, created a python script

Recently been practicing TMUX for my day to day tasks. To be honest, I am late. I should have get used to it earlier. It is much more robust and well sorted than the other terminal multiplexers such as screen. How am I adapting?

Containerization gives us many benefits from packaging to distribution and others. Thus, Docker is widely used as a containerization tool which is designed for running specific tasks and processes, not for hosting operating systems or like other virtualization tools like VMWare, VirtualBox etc. You create a container to serve a single unit task. Once it completes the given task, it stops. The container life-cycle depends on the ongoing process inside of it. Once the process stops,

I have been working with redis and python for sometime. It is fun to play with python and redis. There are so many things can be solved by redis.

• Session persistency
• Caching
• Volatile Datastore
• Job or Message Queue
• Search

And many more. But recently I was thinking about using it as main database. I am not yet sure what kind of problem I might face or what things to optimize when it is about scalability or reliability. I will for sure share my experience.

Here I want to talk about –

Whether you have SSD with NVME Protocol or good old HDD, It is not going to make you feel superior than your Random Access Memory or RAM.

By creating a ramdisk, you can use your unused memory as a super fast disk space and work with it. I do need to use nginx and for caching, I always go to tmpfs which is filesystem type that typically uses ram. How do I create one?

I mostly use Python Flask when I need to develop a Web App or API.

Why? Because it is:

• lightweight
• Very Flexible
• Micro-Service Friendly
• Fast Development

These are one of the main reasons I choose Flask. But mostly I love to code with Flask. There are so many ways to run flask applications. I will write some of them here with code examples.

There are a lot of tools I need to work with. Installing some tools in my workstation and bloating the system is not an option with limited memory capacity, specially in MacBook Air M1 with 8GB of ram. So, I am using docker when using those tools. The day to day life depends on these DB tools –

According to the website, Apache Kafka is an open-source distributed event streaming platform used by thousands of companies for high-performance data pipelines, streaming analytics, data integration, and mission-critical applications.

In this post, I am going to share a basic way to start using Apache Kafka with python.

Recently I have been using a Raspberry Pi 3B+ bought from a classified advertisement site called Bikroy.com. A student wanted to sell this, as his final college project was done. It was cheaper with an acrylic casing and a fan. However, I wanted to use this Pi for several pet projects. Initially I did install Pi-Hole for network wide adblocker and along with samba with a spare portable hard disk. It was working OK. No extra pressure in this 1GB ram Pi. I thought Why not give it a little bit more pressure?

Thus, I planned to install docker registry in it for my “local private docker hub” type of need. Let me share what I had to do.

So, I have a log file that is not single line log. It is kind of java stack trace. What I needed to do is read those log files and create some actions depending on them. I could use already built tools. But I thought why not just do this as simply as printing strings.

This is an example of the log format I wanted to play with. It seems too simple to pile up the Filebeats or elastic stack.

Using git is somehow easier when you just stick into normal workflow or working all alone in a project. Also it is easier as there are many GUI available. But there are some possibility on falling into critical situations where GUI may not be the right tool to stick with. I will share some situations here and the right commands which will save you from doing useless commits.

I enjoy coding and solving problems. But as I go forward, I find myself in a sea of unknowns. Thus I decided to learn as much as possible to be confident. So, I am learning even the simplest it seems.

You have some data in MongoDB with date object in them. You want to delete data from certain date, then here it is:-

I am gonna talk about Git. We all somehow use git and thus it is important for us to better use .gitignore.

Let, you want to protect a page or any site in nginx by certain IP addresses access only. How would you do it in nginx? I will discuss some cases here about the situation.

লিনাক্স এর টার্মিনাল থেকে ফাইল খুজাটা প্রায়ই জরুরী হয়ে উঠে। বিশেষ করে যারা হেডলেস লিনাক্স সার্ভার ব্যবহার করেন তাদের তো এটা প্রতিদিন এর টাস্ক হয়ে উঠে। আমি সহজ এবং প্রতিদিন এর উপকারি কিছু কমান্ড

You might somehow face a huge traffic on your site which is not legitimate at all and kind of DOS. If you can identify the traffic which eventually lessen the site performance by the Basic HTTP Floods DOS, you can save yourself from being affected by mild DOS attack. I will show you how can lessen the chance of being easily affected by those attacks.

Whatever you say against Ubuntu, you can’t just make it less popular. It is the most popular Linux distribution. Many companies rely on this distribution. I personally use it on my laptop and in my servers. Normally people use windows, and when it comes to Linux it becomes a whole other matter. If someone use Ubuntu but later he wanted to install install latest windows or old alongside Ubuntu, he may face problem as loosing Ubuntu. That is what i am gong to explain “Ubuntu Recover Procedure”.

Load Balancing is the mechanism which will balance the load upon server towards several servers which ultimately can handle heavy traffic. I will show you the basic configurations with normal HTML based webpages only but it will help you to build for PHP based websites.

I am going to explain how you can bypass any firewall and become anonymous with the steps to install shadowsocks and then i will also show you how you can connect to one server/location but will show your public ip another. Shadowsocks is very fast tunnel proxy which can bypass the most dangerous firewall like “Great Firewall of China“.

I have Acer Aspire 5733 and i couldn’t change brightness of my laptop. This is annoying and painful. I have tried many things to do this but couldn’t solve it as there is no linux graphics driver. At last i have found a solution and i have written an script which will be helpful for you.

I have been trying to encrypt files and folders lately. It is fun but useful. You can encrypt any file which can take several years to decrypt for a hacker. That “Several” is not less. According to recent super computer “K Computer” which is the fastest can calculate 8,200,000,000,000,000 (8.2 quadrillion) calculations per second. Lets see how many seconds would take to decrypt an encrypted file by the way i am showing.

This article is about showing how to monitor any server or remote server by a tool named munin. Munin the monitoring tool surveys all your computers and remembers what it saw. It presents all the information in graphs through a web interface. Its emphasis is on plug and play capabilities. I will show you how to set it up with a remote server too.

In DOS, OS/2, and also Microsoft Windows, batch file is the name given to a type of script file, a text file containing a series of commands to be executed by the command interpreter. A batch file may contain any command the interpreter accepts interactively at the command prompt. A batch file may also have constructs (IF, GOTO, Labels, CALL, etc.) that enable conditional branching and looping within the batch file. Recently i was playing with it and got a cool script while playing with ping command which will output ping results in a text file in Desktop.

By definition, the first two Fibonacci numbers are 0 and 1, and each subsequent number is the sum of the previous two. I will show you two shell script to generate Fibonacci series recursively and iteratively. Also you will get idea about the application of Fibonacci series/numbers.

rsync is a free software computer program for Unix and Linux like systems which synchronizes files and directories from one location to another while minimizing data transfer using delta encoding when appropriate. An important feature of rsync not found in most similar programs/protocols is that the mirroring takes place with only one transmission in each direction. This tool is very appropriate to keep backup or setup mirror service. In this article you will get some clear idea.

Apache is the most used server. It is used to serve more than half of all active websites. It will be very helpful to understand Apache. Understanding the configuration of virtual host of Apache is important as sometime it will be a tough job to do. I will show you how to set default folder of a website other than root directory of Apache.

I have normally worked with linux servers but sometimes i used Windows too. I have faced password forgetting moments and then after searching and trying i have got the solution to reset Windows Server 2008 R2.

Lubuntu is good. Actually LXDE is good. I love its simplicity. One tricky thing is though how to add a keyboard layout on Lubuntu/LXDE (if you didn’t specify an additional language at installation).  To configure keyboard layouts a big flaw of LXDE. So here is what I did to add a new keyboard layout.

If you have linux server or linux operating system(distribution) in your pc then you are using bash. Bash is a command processor and Unix Shell, typically run in a text window, allowing the user to type commands which cause actions. Bash can also read commands from a file, called a script. Bash keep records of executing commands and all. Sometimes if you want to clean all your records you can follow this.

Me and also many people use WordPress to run website or blog. What is the most fascinating thing of WordPress ? Obviously its resources. It has so many plugins and themes that can make a simple WordPress website act like a super-platform. I am here to show you how to remove little smiley face on the bottom of Wordpres sites.

It is a pain to handle folder permission for new linux users or VPS users. Even some Pro-Linux users also face this problem. However, I will explain here how to give two users to read-write access of a same folder.

My dear readers. I am here again for your help with squid proxy server. I will show you today how to use squid server to work with several IP in a vps/system. This is very useful if you do Craigslist work or something like that. Proxy is interesting. Squid proxy is like a Swiss Army Knife which has numerous feature to make you comfortable with proxy.

Here are two ways of configuring squid’s proxy to use the other IPs assigned to your server (besides the default one).

This week i was trying to be familiar with node and ghost Blog. Launched a blog in my VPS. I will say Over whelming performance. As you can see i have posted how to install it with Apache server. I will now show you some benchmark report by Apache Benchmark tool. Lets see.

“Ghost Blog” is a blogging platform. Just blog. If you are into blogging and sharing your thoughts and nothing else, then you will definitely looking for this one. Very lightweight and super stylish with simplicity look. It is a platform where you will be motivated to write. But it is tricky to install. I will make it simple here.

We do use internet everyday for mailing,sharing thoughts,working,uploading files etc in several sites like Facebook,Twitter,Tumblr,Gmail etc. They are free. But we have to agree with their Terms of service and Privacy Policies. No one reads those i guess 🙂 . But i have found some interesting lines there. I am collecting those lines for fun.

Taking screenshot is now a days very important. This is used for many purpose like writing blog post, sharing problem facing in the system and much more things. There are many tools to take shot of your desktop but here i will show you how to take screenshot by terminal or command line interface in linux based machine.

I have created a script which will download and install 70 Bangla fonts(with variations of them) without searching. Just run this script in your Linux based PC/Laptops terminal and get all Bangla fonts instantly without hassle.

Monitoring server is very important. You can prevent many unwanted things by monitoring regularly. I am assuming that you own a VPS as you are reading this post. You are new happy owner of your personal VPS. So why don’t you take a look about some monitoring tools?

There are sometimes you will get some errors in /var/log/syslog.log saying IPV6 Neighbor Table Overflow and which are really annoying. For fixing this you should follow this.

Server lover like me and you will always try our best to get the full performance from our VPS/Server. Here is a script to show you some interesting thing about your server including download speed from popular Data Center, cpu model, frequency, ram, swap, Uptime I/O Speed etc.

The client API is a http based API that allows you and your clients to interact directly with a virtual server with security and ease. The client API can be disabled at any time and access is only granted with a key and hash on a per vps basis.Currently available options are:

Hello VPS user. Obviously you are or intend to a VPS user as you are reading this. I will share my own experience with you about choosing OS for your VPS. There are plenty of Operating system that can give you pleasure handling the VPS.

IspConfig is a very powerful free server control panel with many features. It has a interesting feature as it generate error pages and default index of each domain. Which you can easily edit and get all future generated pages by your choice.

Perform rsync asks for password on the remote server before starting the transfer. Sometimes we need to run rsync by crontab where it is not possible to give password.  Here is a solution to use crontab to execute rsync without any password.

This is helpful when you are scheduling a cron job for automatic backup using rsync.

Bangladesh decided to connect to world wide web in late 1995 by VSAT or Very Small Aperture Terminal. On June 4, 1996 the VSAT base data circuit was commissioned for the first time in the country. Upon VSAT commissioning, internet connectivity was established & its services were made available to the public. After internet was launched, the June 1996 National polls results were made available to the netizens of the world using World Wide Web. This was the first ever usage event of its kind in Bangladesh. The effort was appreciated in many corners especially among the Bangladeshis living abroad.

After the introduction of Internet,

As you are reading this post i can assume you are the victim of server system read-only. It happens when you messed up your fstab. But you can’t re-edit the /etc/fstab file as your system is in read-only state now. So what to do ? You need a

If you see that your newly created Squid proxy server can’t access Google, Facebook and other sites then you are right place to get the solution. Actually this problem arises when your ISP have no IPV6 for you. And Google,Facebook type giant sites has IPV6. So Squid just route you to access by IPV6 whether you have or not. As you have no IPV6 , you are facing problem.

Here we will learn how to redirect all http request to https in nginx server. Assuming you have success fully installed ssl and can access https manually.

If you have installed ispconfig by following http://www.howtoforge.com/  then you have also installed squirrel mail. You may face attachment problem, Saying data directory is not writable. Here is the solution.

VPN secures your computer’s internet connection to guarantee that all of the data you’re sending and receiving is encrypted and secured from prying eyes. You can get cheap vpn from many vpn providers. But i will show you how to get a private VPN maintained by yourself by less then 4$.

If you have a folder with huge contents and you want to get a list from them what will you do ? Write down one by one ? 😛

In Linux based distributions you can get a list by a simple command.

Lighttpd is one of the speediest webserver which will make you feel like you got a highspeed internet connection with low price. However , i will explain you how to create ssl certificate and use it in lighttpd vhost for accessing particular websites with particular certificate.

If you don’t have any additional disks, you can create a file somewhere on your filesystem, and use that file for swap space. Normally some vps providers don’t give swap. For those who has that type of vps will need this tutorial to get a swap to faster website or vps.

Lighttpd = Security, speed, compliance, and flexibility.

It is pronounced as “Lighty”. Lighttpd is rapidly redefining efficiency of a webserver . It is Designed and optimized for high performance environments. With a small memory footprint compared to other webservers. 128mb ram can run it like a mig29 with several wordpress(I will try two today). It has advanced feature set like FastCGI, SCGI, Auth, Output-Compression,URL Rewriting and many more. It is perfect for every server and also for VPSs with low memory. You will be amazed by its speed with low ram and swap. It is totally free.

This is annoying to get file exceeds the max size allowed when you try for uploading files. How can you be able to upload bigger files without any caution or error ? We have to find php.ini file from your system.

A test with a simple HTML page over a DSL connection shows that one big stylesheet or css of 50 KB can speed up load time by factor 2 compared to five stylesheets that are 10 KB each in size:

• 5 Stylesheets (10KB each): 1100ms
• 1 Stylesheet (50KB): 500ms

So , How to make them one without breaking or editing them ? I am going to show you how to do this .

Browser caching is a good idea to make/feel your site speedy . Your sites visitors will find it much speedier after first visit . If you test your page in pingdom and google speed analysis tool you will see a recommendation there to enable caching . That is why i am sharing this .

Sometimes we need to find file or folder . It is easy in graphical file manager . But in terminal you have to be tricky .

Varnish is an HTTP accelerator designed for content-heavy dynamic web sites. In contrast to other web accelerators, such as Squid, which began life as a client-side cache, or Apache and nginx, which are primarily origin servers, Varnish was designed as an HTTP accelerator. Varnish is focused exclusively on HTTP, unlike other proxy servers that often support FTP, SMTP and other network protocols.

Here , I will explain how to get varnish in front of apache2 or accelerate apache2 with varnish .

Websites are naturally geeks guinea pig . You will get much more spam if you get a website to comment or something . They just don’t stop . Try and try . You will find it very much annoying . You can pause them . Not stop but it will give you peace i think . Now open any text editor and