#!/bin/bash

# install snmp monitoring and configures it

# createUser <username> SHA "<auth password>" AES "<priv password>"
# rouser <username>
# #rwuser <username>

# make sure we are running as sudo
if [ "$EUID" -ne 0 ]; then
  echo "Please run as root"
  exit
fi

if [ -f /etc/debian_version ]; then
    apt update
    apt install -y snmpd curl
elif [ -f /etc/redhat-release ]; then
    dnf install -y net-snmp net-snmp-utils curl
    firewall-cmd --zone=public --add-service=snmp --permanent
    firewall-cmd --reload
else
    echo "You are running an unsupported OS"
    echo "Support OSes: Debian, Ubuntu, CentOS/Rocky 8/9"
    echo "Your OS: ${OS} ${OS_VER}"
    exit
fi


# back the original config file
mv /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.bak

# generate useranme/auth/enc passwords
username=$(openssl rand -hex 8)
authPassword=$(openssl rand -hex 32)
encPassword=$(openssl rand -hex 32)

# create new config file
cat <<EOF >> /etc/snmp/snmpd.conf
CreateUser ${username} SHA ${authPassword} AES ${encPassword}

rouser ${username} priv .1

syslocation Rack, Room, Building, City, Country [GPSX,Y]
syscontact Your Name <your@email.address>

#Distro Detection
extend .1.3.6.1.4.1.2021.7890.1 distro /usr/bin/distro
EOF

# download distro script 
curl -o /usr/bin/distro https://raw.githubusercontent.com/librenms/librenms-agent/master/snmp/distro
chmod +x /usr/bin/distro

systemctl restart snmpd 

systemctl enable snmpd

echo "#########################################################################"
echo "##                        Encryption Details                           ##"
echo "## Please enter the Username and Auth/Enc Passwords on Libernms Server ##"
echo "#########################################################################"
echo "Username = ${username}"
echo "Auth (SHA) Password = ${authPassword}"
echo "Enc (AES) Password = ${encPassword}"