InfoBlox DNS Records Webhook in Kubernetes cluster

Motivation

To automate the creation of DNS records in Infoblox DNS servers when Kubernetes ingress resources are created. Use of External DNS controller was found to be inadequate, perhaps due to the development stage of Infoblox provider in External DNS. To overcome this shortcoming in External DNS, a webhook was created. The webhook examines the ingress resource, extracts the host information sends a request to the Infoblox for creation/deletion of DNS records.

Prerequisites

• Go installation
• Local Kubernetes cluster
• The following commandline utilities:
  • make
  • kubectl
  • helm
• Access to an Infoblox Server test instance

Getting started

helm repo add infoblox-dns-webhook https://middlewaregruppen.github.io/helm-charts
helm repo update

• Create/update a values.yaml file with values suitable for the target environment

helm install infoblox-dns-webhook -n infoblox-dns --create-namespace -f values.yaml

The following variables are used to deploy the webhook

NAME	Description	Type	Default
clusterInfo.name	Name of the cluster where webhook is deployed	string	-
clusterInfo.ingressControllerNamespace	Namespace where ingress controller is deployed	string	ingress-nginx
clusterInfo.ingressControllerName	Ingress controller serviceName	string	ingress-nginx-controller
infobloxInfo.port	Port of the InfoBlox Server port	integer	443
infobloxInfo.protocol	HTTP/HTTPS protocol	string	https
infobloxInfo.server	Domain name or IP of InfoBlox Server	string	infoblox.localdev.me
infobloxInfo.version	InfoBlox version	string	v2.12.1
infobloxInfo.view	Infoblox DNS view	string	default.localdev
infobloxInfo.zone	InfoBlox DNS zone (DNS suffix)	string	localdev.me
infobloxInfo.secret.username	InfoBlox Server user	string	admin
infobloxInfo.secret.password	InfoBlox Server password	string	p4ssw0rd
infobloxInfo.secret.name	Name of secret holding InfoBlox user credentials	string	infoblox-creds
project.name	Name of the webhook used in the admission webhook manifests	string	infoblox-dns-webhook
repository	Container registry where image is stored	string	registry.localdev.me
tls.name	Name of TLS certificate secret	string	infoblox-dns-webhook-tls
tls.cert	TLS certificate content in Base64	string	-
tls.key	TLS key content in Base64	string	-

Example installation with a self-signed certificate:

• Create a self-signed certificate

openssl genrsa -out tls.key
openssl req -new -key tls.key --out tls.csr -subj "/CN=example-hook.example-ns.svc"
openssl x509 -req -extfile <(printf 'subjectAltName=DNS:example-hook.example-ns.svc') -in tls.csr -signkey tls.key -out tls.crt

• Install the helm chart

helm install infoblox-dns-webhook infoblox-dns-webhook/infoblox-dns-webhook -n infoblox-dns --create-namespace \
    --set tls.cert=$(cat tls.crt | base64 | tr -d '\n') \
    --set tls.key=$(cat tls.key | base64 | tr -d '\n') \
    --set infobloxInfo.server=infoblox.localdev.me \
    --set infobloxInfo.secret.username=infoblox \
    --set infobloxInfo.secret.password=p4ssword \
    --set clusterInfo.name=infra-tools-dev \
    --set clusterInfo.ingressControllerNamespace=infra-apps-dev \
    --set clusterInfo.ingressControllerName=infra-apps-controller