Ubuntu/Debian (clean box)

sudo apt-get update
sudo apt-get install -y build-essential libssl-dev git zlib1g-dev
sudo git clone https://github.com/giltene/wrk2.git
cd wrk2
sudo make
# move the executable to somewhere in your PATH
sudo cp wrk /usr/local/bin

Installs the build tools, open ssl dev libs (including headers), and git. Then uses git to download wrk and build.

CentOS / RedHat / Fedora

sudo yum -y groupinstall 'Development Tools'
sudo yum -y install openssl-devel git zlib-devel
git clone https://github.com/giltene/wrk2.git
cd wrk2
make
# move the executable to somewhere in your PATH
# to find your PATH
sudo echo $PATH
# Select appropriate PATH
# CentOS 7 with cPanel PATH example: sudo cp wrk /usr/local/bin
sudo cp wrk /somewhere/in/your/PATH

Installs the build tools, open ssl dev libs (including headers), and git. Then uses git to download wrk and build.