try to use CoreDNS

I get CoreDNS binary file.

[root@cent7devops ~]# wget https://github.com/coredns/coredns/releases/download/v1.2.0/coredns_1.2.0_linux_amd64.tgz
*snip*
[root@cent7devops ~]# ls coredns_1.2.0_linux_amd64.tgz
coredns_1.2.0_linux_amd64.tgz
[root@cent7devops ~]#
[root@cent7devops ~]# tar xfz coredns_1.2.0_linux_amd64.tgz
[root@cent7devops ~]# ls -1 coredns*
coredns
coredns_1.2.0_linux_amd64.tgz
[root@cent7devops ~]#

I check version.

[root@cent7devops ~]# coredns --version
CoreDNS-1.2.0
linux/amd64, go1.10.3, 2e322f6
[root@cent7devops ~]#

Next, I prepare Corefile. Corefile is configuration file of CoreDNS.

[root@cent7devops ~]# vi Corefile
[root@cent7devops ~]# cat Corefile
. {
    whoami
    errors
    log
}
[root@cent7devops ~]#

I run CoreDNS. Default port for CoreDNS is "53".

[root@cent7devops ~]# coredns -conf Corefile
.:53
2018/07/13 01:49:41 [INFO] CoreDNS-1.2.0
2018/07/13 01:49:41 [INFO] linux/amd64, go1.10.3, 2e322f6
CoreDNS-1.2.0
linux/amd64, go1.10.3, 2e322f6

[root@cent7devops ~]# ss -antp | grep 53
LISTEN     0      128         :::53                      :::*                   users:(("coredns",pid=5596,fd=3))
[root@cent7devops ~]#

I set firewall configuration to DNS.

[root@cent7devops ~]# firewall-cmd --list-services
dhcpv6-client ssh
[root@cent7devops ~]# firewall-cmd --add-service dns
success
[root@cent7devops ~]# firewall-cmd --add-service dns --permanent
success
[root@cent7devops ~]# firewall-cmd --list-services
dhcpv6-client ssh dns
[root@cent7devops ~]#

I got response to dig commnad.

[root@cent7devops ~]# dig -p 53 @localhost AAA .

; <<>> DiG 9.9.4-RedHat-9.9.4-61.el7 <<>> -p 53 @localhost AAA .
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 25187
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
*snip*

[root@cent7devops ~]#

When I execute dig command, CoreDNS output the following log in STDOUT.

[::1]:37018 - [13/Jul/2018:01:50:05 +0900] 58016 "A IN aaa. udp 33 false 4096" NOERROR qr,aa,rd 92 0.00010228s
[::1]:43725 - [13/Jul/2018:01:50:05 +0900] 13554 "A IN . udp 30 false 4096" NOERROR qr,aa,rd 82 0.000038707s