Site to site with OpenVPN with TLS and FirewallD on Debian

So I needed to setup a site to site transport between our two datacenters, so our internal network will be able to communicate between the two datacenters easily.

There are a lot of ways to setup site to site VPN link between two networks, in our case let’s take a look at one way using OpenVPN.

This is quite long tutorial so get yourself a bit comfortable so we can get started.

Confirm before executing shutdown/reboot command on linux

I was rushing to leave and was still logged into a server so I wanted to shutdown my laptop, but what I didn’t notice is that I was still connected to the remote server. Luckily before pressing enter I noticed I’m not on my machine but on a remote server. So I was thinking there should be a very easy way to prevent it from happening again, to me or to anyone else.

Compiling Redis Desktop Manager on Debian

So I’ve used redis desktop manager in the past, but suddenly I can’t use it anymore it’s not compiling on debian, and there are no packages for the application. So I decided to find a way to to compile it on my machine, which uses Debian Stretch.

Codility - OddOccurrencesInArray

A non-empty zero-indexed array A consisting of N integers is given. The array contains an odd number of elements, and each element of the array can be paired with another element that has the same value, except for one element that is left unpaired.

Codility - CyclicRotation

A zero-indexed array A consisting of N integers is given. Rotation of the array means that each element is shifted right by one index, and the last element of the array is also moved to the first place. For example, the rotation of array A = [3, 8, 9, 7, 6] is [6, 3, 8, 9, 7]. The goal is to rotate array A K times; that is, each element of A will be shifted to the right by K indexes.

Codility - BinaryGap

A binary gap within a positive integer N is any maximal sequence of consecutive zeros that is surrounded by ones at both ends in the binary representation of N.

For example, number 9 has binary representation 1001 and contains a binary gap of length 2. The number 529 has binary representation 1000010001 and contains two binary gaps: one of length 4 and one of length 3. The number 20 has binary representation 10100 and contains one binary gap of length 1. The number 15 has binary representation 1111 and has no binary gaps.