port 53: Address already in use when installing Streisand on Ubuntu 20.04
Whilst installing Streisand on Ubuntu 20.04 I came across this error related to dnsmasq. Luckily it's simple to solve.
See what's listening:
sudo netstat -tulpn | grep ":53 "
There's something hogging our port! Result:
tcp 0 0 127.0.0.53:53 0.0.0.0:* LISTEN 582/systemd-resolve
udp 0 0 127.0.0.53:53 0.0.0.0:* 582/systemd-resolve
Kill this out of the box Ubuntu service:
# sudo systemctl disable systemd-resolved
Removed /etc/systemd/system/multi-user.target.wants/systemd-resolved.service.
Removed /etc/systemd/system/dbus-org.freedesktop.resolve1.service.
# sudo systemctl stop systemd-resolved
Since you've nuked the built in DNS service head over to /etc/resolv.conf
and change nameserver 127.0.0.53
to something else, such as your local router's IP or 8.8.8.8 (Google) or 1.1.1.1 (Cloudflare).
Retry streisand install, done