Ansible Role: KEA DHCP

Install and configure the KEA DHCP IPv4 server (kea-dhcp4) with a memfile lease database, subnets, pools and host reservations.

Requirements

Operating System	Package	Service
Debian	kea-dhcp4-server	kea-dhcp4-server
Alpine	kea-dhcp4	kea-dhcp4

Dependencies

None (dependencies: []). The playbook only runs the dhcp role.

Variables

Variable	Required	Default	Description
kea_dhcp_interface	No	eth0	Network interface to listen on
kea_dhcp_lease_rebind	No	750	Rebind timer in seconds
kea_dhcp_lease_renew	No	600	Renew timer in seconds
kea_dhcp_lease_lifetime	No	900	Lease lifetime in seconds
kea_dhcp_subnets	Yes	one example subnet	List of DHCP subnets to configure

The default of kea_dhcp_subnets is only an example (example-lan, 192.168.1.0/24). Always override it.

Subnets

Key	Required	Description
name	Yes	Name of the subnet (informational, not rendered)
subnet	Yes	Subnet in CIDR notation
pool	Yes	Address pool, for example 192.168.1.100 - 192.168.1.200
gateway	Yes	Router handed out as the routers option
dns	Yes	DNS server handed out as domain-name-servers
reservations	No	List of reservations

Reservations

Key	Required	Description
hostname	Yes	Hostname of the client
ip	Yes	Reserved IP address
mac	Yes	Hardware address of the client

Example

kea_dhcp_interface: "eth0"
kea_dhcp_lease_lifetime: "3600"
kea_dhcp_subnets:
  - name: "production-lan"
    subnet: "192.168.1.0/24"
    pool: "192.168.1.100 - 192.168.1.200"
    gateway: "192.168.1.1"
    dns: "192.168.1.10"
    reservations:
      - hostname: "server.example.com"
        ip: "192.168.1.50"
        mac: "AA:BB:CC:DD:EE:FF"

Usage

Run the role through Semaphore using playbook.yaml. The playbook first runs ansible-galaxy install -f -r roles/requirements.yml to refresh the role, then runs the dhcp role.

Notes

Item	Value
Configuration	/etc/kea/kea-dhcp4.conf
Leases	/var/lib/kea/dhcp4.leases (memfile, persisted)
Subnet IDs	Assigned by list position (first subnet is 1)

A change to the configuration restarts the KEA service. Reordering subnets changes their IDs.