k8s.github.io

Pre-requisite CoreDNS

• Take me to Lecture

In this section, we will take a look at CoreDNS

Installation of CoreDNS

$ wget https://github.com/coredns/coredns/releases/download/v1.7.0/coredns_1.7.0_linux_amd64.tgz
coredns_1.7.0_linux_amd64.tgz

Extract tar file

$ tar -xzvf coredns_1.7.0_linux_amd64.tgz
coredns

Run the executable file

• Run the executable file to start a DNS server. By default, it’s listen on port 53, which is the default port for a DNS server.

$ ./coredns

Configuring the hosts file

• Adding entries into the /etc/hosts file.
• CoreDNS will pick the ips and names from the /etc/hosts file on the server.

$ cat > /etc/hosts
192.168.1.10    web
192.168.1.11    db
192.168.1.15    web-1
192.168.1.16    db-1
192.168.1.21    web-2
192.168.1.22    db-2

Adding into the Corefile

$ cat > Corefile
. {
	hosts   /etc/hosts
}

Run the executable file

$ ./coredns

References Docs

• https://github.com/kubernetes/dns/blob/master/docs/specification.md
• https://coredns.io/plugins/kubernetes/
• https://github.com/coredns/coredns/releases