CoreDNS

Service Management

Check CoreDNS status:

systemctl status coredns

Restart CoreDNS:

systemctl restart coredns

Reload CoreDNS:

systemctl reload coredns

Stop CoreDNS:

systemctl stop coredns

Start CoreDNS:

systemctl start coredns

View CoreDNS logs:

journalctl -u coredns -f

DNS Configuration

The primary CoreDNS configuration is:

/etc/coredns/Corefile

The default configuration forwards DNS queries to:

1.1.1.1 8.8.8.8

Configure the Corefile according to your specific needs and use case.

After changing the Corefile, restart CoreDNS:

systemctl restart coredns

DNS Endpoints

• DNS: 53/tcp and 53/udp
• Health: http://127.0.0.1:8080/health
• Ready: http://127.0.0.1:8181/ready
• Metrics: http://127.0.0.1:9153/metrics

Important Files & Directories

• Binary: /usr/bin/coredns
• Corefile: /etc/coredns/Corefile
• Service: /etc/systemd/system/coredns.service
• Sysusers: /usr/lib/sysusers.d/coredns.conf
• Tmpfiles: /usr/lib/tmpfiles.d/coredns.conf
• Logrotate: /etc/logrotate.d/coredns
• Data Directory: /var/lib/coredns
• Log File: /var/log/coredns.log
• Error Log: /var/log/coredns.err.log
• Resolver Override: /etc/systemd/resolved.conf.d/99-coredns.conf

Test DNS Resolution

Query CoreDNS directly:

dig @127.0.0.1 example.com

Or query it using the server's IP:

dig @<SERVER-IP> example.com

The host's /etc/resolv.conf is configured to use:

nameserver 127.0.0.1

Notes

• CoreDNS uses systemd-resolved configuration changes to free port 53.
• The host resolver is pointed to 127.0.0.1.
• DNS queries are forwarded to the configured upstream resolvers.
• CoreDNS runs under the dedicated coredns system user.