How to write multiple line string using Bash with variables?

 Solution:

For one record in config file: 

#!/bin/bash
var1="abc"
var2="xyz"
cat >/etc/config.conf <<EOL
line 1, ${var1}
line 2, 
line 3, ${var2}
line 4 line
... 
EOL
cat /etc/config.conf

For multiple  record in config file: 

#!/bin/bash
var1="abc"
var2="xyz"
for i in `cat sometext.txt`
do
cat >>/etc/config.conf <<EOL
line 1, ${var1}
line 2, 
line 3, ${var2}
line 4 line
... 
EOL
done