Installing multiple versions of python on linux using pyenv and create virtual environment.

Environment: Debian12 

Default python version on debian12 is 3.11 but I need 3.10 to run my flask based back end.

1. Check default python version

python3 --version

 

 2. Install version 3.10.13 (chose the version you need)

cd
sudo apt install curl git gcc make libssl-dev libbz2-dev
curl https://pyenv.run | bash
cd .pyenv/bin
./pyenv install --list
./pyenv install 3.10.13
cd ~/.pyenv/versions/3.10.13/bin/
./python3.10 --version

 

3.  Create Virtual Environment

cd ~/.pyenv/versions/3.10.13/bin/
./python3.10 -m venv ~/.venv310

4. To activate virtual environment

cd
source .venv310/bin/activate
(.venv310):~$

 

 

 

Top 4 steps to secure debian / ubuntu

1. Security Update

grep security /etc/apt/sources.list > /tmp/security.list
sudo apt-get upgrade -oDir::Etc::Sourcelist=/tmp/security.list'
 

2. IPS/IDS using fail2ban

apt-get install rsyslog
apt-get install fail2ban
 

3. Install and enable firewall using ufw

vi /etc/myufw.sh

#!/bin/bash
ufw=/usr/sbin/ufw
$ufw disable
$ufw default deny incoming
$ufw default allow outgoing
$ufw allow ssh
$ufw allow https 
$ufw allow 5000 
$ufw allow 3000 
$ufw allow 7000
$ufw - force enable

$sudo chmod +x /etc/myufw.sh

$ sudo chmod /etc/myufw.sh

$ sudo iptables -L -n 
 

4. Enable only key based authentication:

vi /etc/ssh/sshd_config and check following 2 lines
PasswordAuthentication no
PermitRootLogin no

$sudo systemctl restart ssh