dhcp-configuration

DHCP Configuration for OpenShift 4

The DHCP Server is used to assign coreos nodes with the correct ip address. Note the machine name below will name the RHCOS machine with the name name upon boot.

Install dhcp package

sudo yum install -y  dhcp-server

Update dhcp.conf file

authoritative;
ddns-update-style interim;
default-lease-time 14400;
max-lease-time 14400;

option routers                  192.168.1.1;
option broadcast-address        192.168.1.255;
option subnet-mask              255.255.255.0;
option domain-name-servers      192.168.1.245; # your dns server
option domain-name              "example.com"; # your domain fqdn


subnet 192.168.1.0 netmask 255.255.255.0 {
   	pool {
      	range 192.168.1.75 192.168.1.90; # this can be changed to the range you would like dhcp to use

      	# Static entries
      	host bootstrap-0 { hardware ethernet 52:54:00:x:x:x; fixed-address 192.168.1.76; }
      	host master-01 { hardware ethernet 52:54:00:x:x:x; fixed-address 192.168.1.77; }
      	host master-02 { hardware ethernet 52:54:00:x:x:x; fixed-address 192.168.1.78; }
      	host master-03 { hardware ethernet 52:54:00:x:x:x; fixed-address 192.168.1.79; }
      	host worker-01 { hardware ethernet 52:54:00:x:x:x; fixed-address 192.168.1.80; }
      	host worker-02 { hardware ethernet 52:54:00:x:x:x; fixed-address 192.168.1.81; }

      	# this will not give out addresses to hosts not listed above
      	deny unknown-clients;

      	# this is PXE specific
      	filename "pxelinux.0";
      	next-server 192.168.1.80; # your PXE Server
         	}
}

Start the dhcpd service

sudo systemctl start dhcpd

Check the status of the dhcp process

sudo systemctl status dhcpd