ExternalDNS configuration reference for Lokomotive

Introduction

ExternalDNS is a Kubernetes addon that synchronizes exposed Kubernetes Services and Ingresses with DNS providers to make them discoverable.

Prerequisites

A Lokomotive cluster accessible via kubectl.
An ingress controller such as Contour for HTTP ingress.

Configuration

ExternalDNS component with Contour supports managing DNS records for Services of type LoadBalancer only. More information on this limitation is explained in this issue .

ExternalDNS component currently supports AWS Route53 DNS provider.

ExternalDNS component configuration example:

component "external-dns" {
  # Required arguments.
  aws {
    # Required arguments
    zone_type = "public"
    zone_id = "ZQXH02G1EPZ6R"
    # Optional arguments.
    aws_access_key_id = ""
    aws_secret_access_key = ""
  }

  # Optional arguments.
  sources = ["ingress"]
  namespace = "external-dns"
  policy = "upsert-only"
  metrics = false
}

Attribute reference

Table of all the arguments accepted by the component.

Argument	Description	Default	Type	Required
`sources`	Kubernetes resources type to be observed for new DNS entries by ExternalDNS.	[“ingress”]	list(string)	false
`namespace`	Namespace to install ExternalDNS.	“external-dns”	string	false
`policy`	Modify how DNS records are synchronized between sources and providers (options: sync, upsert-only).	“upsert-only”	string	false
`metrics`	Enable metrics collection by Prometheus. Needs Prometheus Operator component installed.	false	bool	false
`owner_id`	A name that identifies this instance of ExternalDNS. Set it to a unique value across the DNS zone that doesn’t change for the lifetime of the cluster.	-	string	true
`aws`	Configuration block for AWS Route53 DNS provider.	-	object	true
`aws.zone_type`	Filter for zones of this type (options: public, private).	“public”	string	false
`aws.zone_id`	ID of the DNS zone.	-	string	true
`aws.aws_access_key_id`	AWS access key ID for AWS credentials. Use environment variable AWS_ACCESS_KEY_ID instead.	-	string	false
`aws.aws_secret_access_key`	AWS secret access key for AWS credentials. Use environment variable AWS_SECRET_ACCESS_KEY instead.	-	string	false

Applying

To apply the ExternalDNS component:

lokoctl component apply external-dns

Deleting

To destroy the component:

lokoctl component delete external-dns --delete-namespace