I have a program that will run a set of commands against new server installs and I need to change an entry in a file for each install. We need to change the default DNS from 127.0.0.X (which it defaults to as it installs without an internet connection) to 8.8.8.8
I was using the following command:
sudo awk '{sub(/#DNS=/,"DNS=8.8.8.8")}' /etc/systemd/resolved.conf
however this doesn't appear to be working under gawk/new OS version.
sudo gawk '{gensub(/#DNS=/,"DNS=8.8.8.8")}' /etc/systemd/resolved.conf
What am I doing wrong? Is there a better way to change the default DNS entry?
Current Server OS: Ubuntu 24.04.2-live-server
Previous Server OS: Ubuntu 20.04.6-live-server
EDIT:
Sample line input file:
#DNS=
#FallbackDNS=
#Domains
The command should find the first line above and replace it with DNS=8.8.8.8 however it is not. When
Desired output:
DNS=8.8.8.8
#FallbackDNS=
#Domains
When I run the awk command the file still reads:
#DNS=
#FallbackDNS=
#Domains
Additionally, it should only find and replace an exact match of #DNS=
What command and syntax will replace #DNS= with DNS=8.8.8.8?
