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External-DNS Setup Guide

ExternalDNS synchronizes exposed Kubernetes Services and Ingresses with DNS providers.

What it does?

Inspired by Kubernetes DNS, Kubernetes’ cluster-internal DNS server, ExternalDNS makes Kubernetes resources discoverable via public DNS servers. Like KubeDNS, it retrieves a list of resources (Services, Ingresses, etc.) from the Kubernetes API to determine a desired list of DNS records. Unlike KubeDNS, however, it’s not a DNS server itself, but merely configures other DNS providers accordingly—e.g. AWS Route 53 or Google Cloud DNS.

Prerequisites (required for Support on TrueCharts Discord)

  • Traefik
  • Clusterissuer / Cert-manager installed (vital if exposed externally)

Please follow the Getting Started guide on the Truecharts website.

Installation instructions

This guide will cover 2 scenarios, Cloudflare and Pi-Hole / Pihole, for more external DNS record providers, see External-DNS Docs.

Cloudflare

These instructions taken from external-dns cloudflare tutorial

Step 1

Enter CF_API_TOKEN (preferred) or CF_API_EMAIL/CF_API_KEY

Cloudflare API Token

Step 2

Enter preferences for Logs and DNS updates (I suggest >5m to prevent log spam) and select cloudflare as provider and select sources. I find ingress and service covers everything. If you want to filter by multiple domains add your Domain Filter Entry

Cloudflare App Config 1

I recommend using noop for Registry Type and leaving the rest as default, can add DNS Zone filters as necessary as well (see upstream/cloudflare docs).

Cloudflare App Config 2

Step 3

Verify it works, check the logs for updates to DNS records

Terminal window
2023-11-07 09:36:07.165596-05:00time="2023-11-07T09:36:07-05:00" level=info msg="Instantiating new Kubernetes client"
2023-11-07 09:36:07.165633-05:00time="2023-11-07T09:36:07-05:00" level=info msg="Using inCluster-config based on serviceaccount-token"
2023-11-07 09:36:07.165850-05:00time="2023-11-07T09:36:07-05:00" level=info msg="Created Kubernetes client https://172.17.0.1:443"
2023-11-07 09:36:08.958946-05:00time="2023-11-07T09:36:08-05:00" level=info msg="Changing record." action=CREATE record=seafile.DOMAIN.com ttl=1 type=A zone=d959ce24eb85d78a7f527b6150446335

If this works, you’ll see DNS entries inside Cloudflare’s DNS page.

PiHole

Step 1

Ignore Provider Credentials, and skip straight to App Configuration and select pihole, add domain filters as necessary

PiHole App Config 1

Change to noop for Registry Type and add PiHole Server Address (default is http://pihole.ix-pihole.svc.cluster.local:9089) and PiHole Server Password

PiHole App Config 2

Step 2

Verify logs from External-DNS to see if it connects and updates PiHole

Terminal window
d:false IBMCloudConfigFile:/etc/kubernetes/ibmcloud.json TencentCloudConfigFile:/etc/kubernetes/tencent-cloud.json TencentCloudZoneType: PiholeServer:http://pihole.ix-pihole.svc.cluster.local:9089 PiholePassword:****** PiholeTLSInsecureSkipVerify:false PluralCluster: PluralProvider:}"
2023-11-07 10:29:07.801555-05:00time="2023-11-07T10:29:07-05:00" level=info msg="Instantiating new Kubernetes client"
2023-11-07 10:29:07.801568-05:00time="2023-11-07T10:29:07-05:00" level=info msg="Using inCluster-config based on serviceaccount-token"
2023-11-07 10:29:07.801861-05:00time="2023-11-07T10:29:07-05:00" level=info msg="Created Kubernetes client https://172.17.0.1:443"
2023-11-07 10:29:08.008741-05:00time="2023-11-07T10:29:08-05:00" level=info msg="add firezone.DOMAIN.com IN A -> 192.168.88.105"
2023-11-07 10:29:10.048171-05:00time="2023-11-07T10:29:10-05:00" level=info msg="add scrutiny.DOMAIN.com IN A -> 192.168.88.105"

Check PiHole GUI for A records under Local DNS

PiHole-GUI

Enjoy!