Expose Kubernetes services with mDNS

This tutorial shows how to use MetalLB and ExternalDNS to expose services (and ingresses) with .local hostname in LAN using mDNS.

Note: This approach is only suitable for test clusters in local area network.

Following projects are used

• Avahi as mDNS server
• ExternalDNS fork with hosts file provisioner support

Installation

Install MetalLB to assign public IP for services. The IP range should be changed to the IP address range of your network:

kubectl apply -f https://raw.githubusercontent.com/google/metallb/v0.7.3/manifests/metallb.yaml

kubectl apply -f - <<EOF
apiVersion: v1
kind: ConfigMap
metadata:
  namespace: metallb-system
  name: config
data:
  config: |
    address-pools:
    - name: default
      protocol: layer2
      addresses:
      - 192.168.1.100-192.168.1.250
EOF

Install Avahi mDNS daemon on the master node

apt-get install -y avahi-daemon

Install fork of ExternalDNS

kubectl apply -f https://raw.githubusercontent.com/tsaarni/k8s-external-mdns/master/external-dns-with-avahi-mdns.yaml

ExternalDNS listens for externally published services and writes hosts name to /etc/avahi/hosts for Avahi to pick up and serve using mDNS.