As part of some work to resolve a kubernetes application deployment.
The particular application i\u2019m working with has hard dependencies on DNS, particularity, A, TXT and SRV records.
For each kubernetes pod that spins up, i need it to register itself into DNS.
Then the other services can discover themselves.
Here is a basic excerpt of enabling DDNs updates on example.com
Install the basics
apt-get install bind bind9utils dnsutilsForward Lookup Zone
cat > /etc/named/db.example.com.conf <<EOF
$ORIGIN .
$TTL 86400 ; 1 day
example.com IN SOA example.com. root.example.com. (
3 ; serial
604800 ; refresh (1 week)
86400 ; retry (1 day)
2419200 ; expire (4 weeks)
86400 ; minimum (1 day)
)
NS ns1.example.com.
$ORIGIN example.com.
ns1 A 10.1.1.6 ; replace with your server IP address.
EOFReverse Lookup Zone
cat > /etc/named/db.10.1.1.conf <<EOF
$TTL 86400
@ IN SOA example.com. root.example.com. (
1 ; Serial
604800 ; Refresh
86400 ; Retry
2419200 ; Expire
86400 ) ; Negative Cache TTL
;
@ IN NS ns1.example.com.
6 IN PTR ns1.example.com. ; replace 6 with your server ip last octet
EOFNamed local config (should be included from named.conf)
cat > /etc/named/named.conf.local <<EOF
zone "example.com" IN
{
type master;
file "/etc/bind/db.example.com.conf";
notify no;
allow-query {any;};
allow-update { key "rndc-key"; };
};
zone "1.1.10.in-addr.arpa" {
type master;
notify no;
file "/etc/bind/db.10.1.1.conf";
allow-update { key "rndc-key"; };
};
key "rndc-key" {
algorithm hmac-md5;
secret "VBJev6+xzhFVXXYY7tAq4A=="; // this came from the rndc-key file /etc/bind
};
EOFKey file
cat > /etc/named/rndc-key <<EOF
key "rndc-key" {
algorithm hmac-md5;
secret "VBJev6+xzhFVXXYY7tAq4A==";
};
EOFFix any permissions issues and restart the server
chown root:bind /etc/bind/*
chmod g+w /etc/bind
systemctl restart bind9.serviceTest the DDNS updates works
(
echo "server 127.0.0.1"
echo "zone example.com"
echo "update delete xyz.example.com A"
echo "update add xyz.example.com 120 A 192.0.2.1"
echo "send"
) | /usr/bin/nsupdate -k "/etc/bind/rndc.key"Nslookup for good measure
nslookup xyz.example.com 127.0.0.1
