Ubuntu EOL distribution update process

update.sh

#get codename 

echo "Getting ubuntu codename..."
CODENAME=$(lsb_release -c)

#add patched eol sources to list /etc/apt/sources.list

echo "Patching sources.list..."
echo "## EOL upgrade sources.list \
# Required \
deb http://old-releases.ubuntu.com/ubuntu/ $CODENAME main restricted universe multiverse \
deb http://old-releases.ubuntu.com/ubuntu/ $CODENAME-updates main restricted universe multiverse \
deb http://old-releases.ubuntu.com/ubuntu/ $CODENAME-security main restricted universe multiverse \
\
# Optional \
#deb http://old-releases.ubuntu.com/ubuntu/ $CODENAME-backports main restricted universe multiverse \
" >> /etc/apt/sources.list

#update lists again

sudo apt update
sudo apt-get -y dist-upgrade
sudo do-release-upgrade