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Tutorials

The tutorial guides you through the commonly referred topics in the Cloud DNS such as:

ExternalDNS: Cloud DNS offers ExternalDNS integration that makes Kubernetes resources discoverable via the public DNS servers. For more information, see ExternalDNS for Managed Kubernetes tutorial.

Set Up a Secondary Zone: Guides you through how to set up a primary zone in IONOS Cloud Dedicated Core server and a secondary zone with Cloud DNS. For more information, see Set Up a Secondary Zone tutorial.

ExternalDNS for Managed Kubernetes

ExternalDNS Overview

ExternalDNS is an open-source tool that automates the management of public DNS records for Kubernetes resources such as services and ingresses, that are publicly exposed outside the cluster.

The ExternalDNS solution offers the following capabilities:

Control to developers to manage DNS resources that are usually managed manually by third teams. Example: Infrastructure team.
Ensures that the DNS records are always up-to-date with the current state of the Kubernetes cluster.
Manages a large number of records automatedly.
Simplifies the management of DNS records with improved security.

Deployment of ExternalDNS on Managed Kubernetes

Prerequisites: Ensure that you have the following before you begin:

A domain name that is registered with your domain provider aka Registrar or a subdomain under your control.
A token from a user with privileges to manage zones and records with Cloud DNS.
An IONOS Managed Kubernetes cluster.
The kubectl installed on your local machine.
The Helm tool for installing a Helm chart.

Follow these steps to set up ExternalDNS for your Managed Kubernetes with IONOS DNS Provider Cloud DNS:

Prepare domain name: You need to first Create a DNS Zone for your domain name with Cloud DNS and then Connect Domain Name to Cloud DNS.
Add Helm chart: Add the Bitnami Helm repository, which contains the official external-dns Helm chart.

helm repo add bitnami https://charts.bitnami.com/bitnami

Create configuration: Create values file for ExternalDNS Helm chart that includes the plugin configuration. In this example, the values file is called external-dns-ionos-values.yaml.

# OCI image of ExternalDNS that contains the plugin provider feature
image:
  registry: ghcr.io
  repository: ionos-cloud/external-dns-plugin-provider
  tag: latest

# Modify how DNS records are synchronised between sources and providers (default: sync, options: sync, upsert-only, create-only)
policy: sync

# provider needs to be set to plugin
provider: plugin

# url of the provider which the external-dns will target
extraArgs:
  plugin-provider-url: http://localhost:8888

# plugin is deployed as sidecar
sidecars:
  - name: ionos-plugin
    image: ghcr.io/ionos-cloud/external-dns-ionos-plugin:latest
    ports:
      - containerPort: 8888
        name: http
    livenessProbe:
      httpGet:
        path: /health
        port: http
      initialDelaySeconds: 10
      timeoutSeconds: 5
    readinessProbe:
      httpGet:
        path: /health
        port: http
      initialDelaySeconds: 10
      timeoutSeconds: 5
    env:
      # Set port of plugin (value needs to match the container port and plugin provider url port, default value: 8888)
      - name: SERVER_PORT
        value: "8888"
      # Listen on all interfaces for kubernetes probes
      - name: SERVER_HOST
        value: ""
      # Limit possible target zones by a domain suffix (optional)
      - name: DOMAIN_FILTER
        value: "example1.com,example2.com"
      # Exclude subdomains (optional)
      - name: EXCLUDE_DOMAIN_FILTER
        value: "example3.com"
      # Limit possible domains and target zones by a Regex filter. Overrides domain-filter (optional)
      - name: REGEXP_DOMAIN_FILTER
        value: ".*.example4.com"
      # Regex filter that excludes domains and target zones matched by regex-domain-filter (optional)
      - name: REGEXP_DOMAIN_FILTER_EXCLUSION
        value: ".*.example5.com"
      # When enabled, prints DNS record changes rather than actually performing them (default: false)
      - name: DRY_RUN
        value: "true"         
      # Token for DNSaaS rest API authentication (mandatory)  
      - name: IONOS_API_KEY
        value: "21215454"
      - name: LOG_LEVEL
        value: debug
      # When enabled debug logs for the DNSaaS rest API are enabled (default: false)  
      - name: IONOS_DEBUG
        value: "true"

Install ExternalDNS: To install ExternalDNS with Bitnami Helm chart, use the following commad:

helm install external-dns-ionos bitnami/external-dns -f external-dns-ionos-values.yaml

Deploy application: Follow this step to deploy an application:

Deploy an echo server application by using the file echoserver_app.yaml.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: echoserver
  namespace: echoserver
spec:
  replicas: 1
  selector:
    matchLabels:
      app: echoserver
  template:
    metadata:
      labels:
        app: echoserver
    spec:
      containers:
      - image: ealen/echo-server:latest
        imagePullPolicy: IfNotPresent
        name: echoserver
        ports:
        - containerPort: 80
        env:
        - name: PORT
          value: "80"
---
apiVersion: v1
kind: Service
metadata:
  name: echoserver
  namespace: echoserver
spec:
  ports:
    - port: 80
      targetPort: 80
      protocol: TCP
  type: ClusterIP
  selector:
    app: echoserver
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: echoserver
  namespace: echoserver
  annotations:
    kubernetes.io/ingress.class: nginx
spec:
  rules:
  - host: app.example1.com #This is your subdomain / record name
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: echoserver
            port:
              number: 80

If you want to use a service, you do not need to install an ingress controller. You can install an ingress controller in the cluster and deploy the application with kubectl by using the following command:

kubectl apply -f echoserver_app.yaml

Result: The deployment of ExternalDNS on Managed Kubernetes is complete.

Verify deployment

You can verify that the application deployed is functioning as expected by using one of the following options.

Access application

Check that the echo server app runs on the subdomain you have specified by using the following command:

curl -I app.example1.com/?echo_code=404-300

Expected result:

HTTP/1.1 404 Not Found 
HTTP/1.1 300 Multiple Choices

Check DNS records

Check that the new A and TXT records are created by using the following command:

curl --location --request GET 'https://dns.de-fra.ionos.com/records?filter.name=app' \
--header 'Authorization: Bearer eyJ0eXAiOiJKV1QiLCJraWQiOiI4MmE5' \
--data ''

Set Up a Secondary Zone

This tutorial explains how to set up a secondary DNS zone in IONOS Cloud by running a bind9 server on an Ubuntu operating system. The setup includes the following configuration steps:

Set up a Dedicated Core server in IONOS Cloud.
Configure a primary nameserver on a Dedicated Core Server in IONOS Cloud running a bind9 server on an Ubuntu operating system.
Create a secondary DNS zone using IONOS Cloud DNS API.
Establish and verify the zone transfer between primary and secondary zones.

Set up a Dedicated Core Server in IONOS Cloud

Note:

The user who creates the server has full root or administrator access rights. A server, once provisioned, retains all its settings (resources, drive allocation, password, and so on), even after server restart at the operating system level.
The server will only be removed from your virtual data center once you delete it in the DCD.

To set up a Dedicated Core server in IONOS Cloud, follow these steps:

1. Create a Dedicated Core server and configure the server in the Settings tab by following the steps in Create a Dedicated Core Server.

2. Configure the server Network settings by following the steps in the Dedicated Core Server network settings.

3. Configure the server Storage settings by following the steps in the Dedicated Core Server storage settings.

4. Continue to provision the changes and start the Dedicated Core Server by following the steps in the Provision changes and starting the Dedicated Core Server.

Result: A Dedicated Core Server is set up and started along with the configuration of Settings, Network, and Storage setup.

Dedicated Core Server network settings

In the DCD > Inspector pane on the right, configure the following network details in the Network tab.

1. Name: Choose a name unique to this Virtual Data Center (VDC).

2. MAC: Assigned on VM creation.

3. LAN: Select the LAN connection that is connected to the internet, by default LAN 1.

4. Firewall: By default, the firewall is disabled. To enable firewall rules, make sure that incoming and outgoing traffic is allowed on port 53 for UDP and TCP.

5. IPv4 Configuration: Leave to default values.

Result: The Network settings for a Dedicated Core server are configured.

Dedicated Core Server storage settings

Warning: The storage type cannot be changed after provisioning.

In the DCD > Inspector pane on the right, configure the following storage details in the Storage tab.

1. Click SSD and a new pop-up window Create New Attached Storage appears.

2. Configure the following storage details:

Name: Enter a name that is unique within your VDC.
Availability Zone: Leave on "Auto".
Size in GB: Enter "30" which is sufficient for this tutorial.
Performance Select "Standard".
Image: You can select one of IONOS images or snapshots, or use your own. For this tutorial, we will use an Ubuntu server image from IONOS. To make the same choice, select ubuntu-22.04-server-cloudimg-amd64 under IONOS Images.
Password: Create a password for the "root" user of the server. You will need this password to SSH and make changes.
SSH Keys: Select an SSH key stored in the SSH Key Manager.
Ad-hoc SSH Key: If you have not created an SSH key, copy and paste the public part of your SSH key into this field.
Cloud-Init user data: Leave on "No configuration".
Boot from Device: Select this checkbox to make the SSD drive bootable.

3. Click Create SSD Storage to create the SSD storage.

Result: The Storage settings for a Dedicated Core server are configured.

Provision changes and start the Dedicated Core Server

1. Select the newly created Dedicated Core server.

2. From the Settings tab in the Inspector pane, select Power > Start.

3. Click Provision Changes in the lower right corner and further click Provision Now.

Result: The Dedicated Core server is provisioned and started.

Next steps: After your changes are provisioned and the server is started, select your Dedicated Core server, click the Network tab in the Inspector pane and copy the IPv4 address.

Configure a Dedicated Core Server as a primary nameserver

Prerequisite: A Dedicated Core server in IONOS Cloud needs to be set up and you must have the IPv4 address of the server.

To configure a Dedicated Core server and enable it to act as the primary nameserver, follow these steps:

1. SSH into the newly created Dedicated Core server.

ssh root@<IP-ADDRESS>

2. Connect to the newly created server via SSH.

root@ubuntu:~# sudo -i
root@ubuntu:~# apt update -y
[...]
root@ubuntu:~# apt install -y bind9 bind9utils
[...]

3. Proceed with configuring bind9 and your primary DNS zone.

root@ubuntu:~# vi /etc/bind/named.conf.local

4. Configure notify to the IONOS Cloud DNS anycast nameserver and allow zone update from localhost.

Note: For sending DNS notify messages, Cloud DNS uses the following Anycast addresses: IPv4 212.227.123.25 or IPv6 2001:8d8:fe:53::5cd:25.

logging {
  category xfer-out { default_syslog; };
  category xfer-in { default_syslog; };
  category notify { default_syslog; };
  category lame-servers { default_syslog; };
  category general { default_syslog; };
  category default { default_syslog; };
};


zone "primary-zone.de" IN {
  type master;
  file "/var/cache/bind/primary-zone.de.db";
  notify explicit;
  also-notify  { 212.227.123.25; };
  allow-update { 127.0.0.1; };
};

5. Create your primary zone.

root@ubuntu:~# vi /var/cache/bind/primary-zone.de.db

6. Edit the zone file.

; Zone: primary-zone.de
; Exported: Mon Aug 17 22:36:11 UTC 2023
 
$ORIGIN primary-zone.de.
$TTL 3600
 
@   3600    IN  SOA primary-zone.de. hostmaster.primary-zone.de. (
                    2017060104  ; serial
                    28800       ; refresh
                    7200        ; retry
                    604800      ; expire
                    600 )       ; minimum
@   3600    IN  NS  ns.ui-global-dns.com.
@   3600    IN  NS  ns.ui-global-dns.de.
@   3600    IN  NS  ns.ui-global-dns.org.
@   3600    IN  NS  ns.ui-global-dns.biz.
www 60    IN  A   127.0.0.1
www 60    IN  AAAA    ::1

7. Save your changes and quit the Vim editor.

8. Check the configuration, reload bind, and verify that the configured zone is working.

root@ubuntu:~# named-checkconf
root@ubuntu:~# systemctl reload named
root@ubuntu:~# dig +short primary-zone.de

Result: The Dedicated Core server is configured as the primary nameserver in IONOS Cloud running a bind9 server on an Ubuntu operating system.

Create a secondary zone in IONOS Cloud DNS

Prerequisite: A Dedicated Core server in IONOS Cloud is set up as a primary nameserver.

To create a secondary zone in the IONOS Cloud DNS by using the REST API, follow this step:

Send a POST request to the /secondaryzones endpoint.

curl --location 'https://dns.de-fra.ionos.com/secondaryzones' \
--header 'Content-Type: application/json' \
--header 'Authorization: Bearer eyJ0eXAiOiJKV1QiLCJraWQiO' \
--data '{
    "properties": {
        "zoneName": "primary-zone.de",
        "description": "This is a secondary zone for primary-zone.de in IONOS Cloud DNS",
        "primaryIps": [
            "<IP-ADDRESS>"
        ]
    }
}'

Response

{
    "id": "bdae7da0-0363-49d7-929d-92992786efe1",
    "type": "secondaryzone",
    "href": "/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1",
    "metadata": {
        "createdDate": "2023-08-06T19:36:58+00:00",
        "lastModifiedDate": "2023-08-06T19:36:59+00:00",
        "nameservers": [
            "nscs-ic.ui-dns.com",
            "nscs-ic.ui-dns.de",
            "nscs-ic.ui-dns.org",
            "nscs-ic.ui-dns.biz"
        ],
        "state": "AVAILABLE"
    },
    "properties": {
        "description": "This is a secondary zone for test-dns-public.info in IONOS Cloud DNS",
        "primaryIps": [
            "<IP-ADDRESS>"
        ],
        "zoneName": "test-dns-public.info"
    }
}

Result: A secondary zone in IONOS Cloud DNS is successfully created By using a POST request.

Verify zone transfer

On the primary nameserver, you can verify the zone transfer in the logs by executing the following command:

root@ubuntu:~# journalctl --unit named --follow
Aug 07 14:43:39 ubuntu named[2666]: client @0x7f467825b958 212.227.123.26#33308 (primary-zone.de): transfer of 'primary-zone.de/IN': AXFR started (serial 2017060104)
Aug 07 14:43:39 ubuntu named[2666]: client @0x7f467825b958 212.227.123.26#33308 (primary-zone.de): transfer of 'primary-zone.de/IN': AXFR ended: 1 messages, 8 records, 299 bytes, 0.001 secs (299000 bytes/sec) (serial 2017060104)

You can also verify zone transfer status using IONOS Cloud DNS API:

curl --location 'https://dns.de-fra.ionos.com/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1/axfr' \
--header 'Authorization: Bearer eyJ0eXAiOiJKV1QiLCJraWQiO'

Response

On success response: 200 OK

{
    "items": [
        {
            "errorMessage": "",
            "primaryIp": "<IP-ADDRESS>",
            "status": "OK"
        }
    ],
    "type": "collection"
}

Result: The zone transfer between primary and secondary zones is successfully verified.

Add a record

To add a record, follow these steps:

1. On the primary nameserver, update the zone with a new record setting—A record to a TEST-NET-3 IP address:

root@ubuntu:~# dig +short www. primary-zone.de @ns.ui-global-dns.com
217.160.0.148
root@ubuntu:~# nsupdate
> server 127.0.0.1
> zone primary-zone.de
> update add www2.primary-zone.de. 600 IN A 203.0.113.1
> send
> quit

2. Resolve the new record locally.

root@ubuntu:~# dig +short www2.primary-zone.de @127.0.0.1
203.0.113.1

3. View the logs which show that a notification is sent to the secondary zone for the new record.

Aug 07 16:00:22 ubuntu named[2666]: client @0x7f467000d0a8 127.0.0.1#34056: updating zone 'primary-zone.de/IN': adding an RR at 'www2.primary-zone.de' A 203.0.113.1
Aug 07 16:00:22 ubuntu named[2666]: zone primary-zone.de/IN: sending notifies (serial 2017060105)

4. Using Cloud DNS API, verify that the newly added record is transferred to the secondary zone.

curl --location 'https://dns.de-fra.ionos.com/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1/records' \
--header 'Authorization: Bearer eyJ0eXAiOiJKV1QiLCJraWQiO'

{
    "id": "bdae7da0-0363-49d7-929d-92992786efe1",
    "type": "collection",
    "href": "/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1/records?limit=100&offset=0",
    "metadata": {
        "primaryIps": [
            "<IP-ADDRESS>"
        ]
    },
    "items": [
        {
            "type": "record",
            "metadata": {
                "fqdn": "primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "primary-zone.de hostmaster.primary-zone.de 2017060105 28800 7200 604800 600",
                "enabled": true,
                "name": "",
                "priority": 0,
                "ttl": 3600,
                "type": "SOA"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "ns.ui-global-dns.de",
                "enabled": true,
                "name": "",
                "priority": 0,
                "ttl": 3600,
                "type": "NS"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "ns.ui-global-dns.biz",
                "enabled": true,
                "name": "",
                "priority": 0,
                "ttl": 3600,
                "type": "NS"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "ns.ui-global-dns.com",
                "enabled": true,
                "name": "",
                "priority": 0,
                "ttl": 3600,
                "type": "NS"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "ns.ui-global-dns.org",
                "enabled": true,
                "name": "",
                "priority": 0,
                "ttl": 3600,
                "type": "NS"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "www.primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "127.0.0.1",
                "enabled": true,
                "name": "www",
                "priority": 0,
                "ttl": 3600,
                "type": "A"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "www.primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "0:0:0:0:0:0:0:1",
                "enabled": true,
                "name": "www",
                "priority": 0,
                "ttl": 3600,
                "type": "AAAA"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "www2.primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "203.0.113.1",
                "enabled": true,
                "name": "www2",
                "priority": 0,
                "ttl": 3600,
                "type": "A"
            }
        }
    ],
    "offset": 0,
    "limit": 100,
    "_links": {
        "self": "/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1/records?limit=100&offset=0",
        "next": "/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1/records?limit=100&offset=100"
    }
}

5. Globally resolve a new record from the IONOS Cloud DNS anycast network by using the following command:

root@ubuntu:~# dig +short www2.primary-zone.de @ns.ui-global-dns.com.

Result: A record is successfully added to the primary nameserver.

ExternalDNS for Managed Kubernetes

ExternalDNS Overview

ExternalDNS is an open-source tool that automates the management of public DNS records for Kubernetes resources such as services and ingresses, that are publicly exposed outside the cluster.

The ExternalDNS solution offers the following capabilities:

Control to developers to manage DNS resources that are usually managed manually by third teams. Example: Infrastructure team.
Ensures that the DNS records are always up-to-date with the current state of the Kubernetes cluster.
Manages a large number of records automatedly.
Simplifies the management of DNS records with improved security.

Deployment of ExternalDNS on Managed Kubernetes

Prerequisites: Ensure that you have the following before you begin:

A domain name that is registered with your domain provider aka Registrar or a subdomain under your control.
A token from a user with privileges to manage zones and records with Cloud DNS.
An IONOS Managed Kubernetes cluster.
The kubectl installed on your local machine.
The Helm tool for installing a Helm chart.

Follow these steps to set up ExternalDNS for your Managed Kubernetes with IONOS DNS Provider Cloud DNS:

Prepare domain name: You need to first Create a DNS Zone for your domain name with Cloud DNS and then Connect Domain Name to Cloud DNS.
Add Helm chart: Add the Bitnami Helm repository, which contains the official external-dns Helm chart.

helm repo add bitnami https://charts.bitnami.com/bitnami

Create configuration: Create values file for ExternalDNS Helm chart that includes the plugin configuration. In this example, the values file is called external-dns-ionos-values.yaml.

# OCI image of ExternalDNS that contains the plugin provider feature
image:
  registry: ghcr.io
  repository: ionos-cloud/external-dns-plugin-provider
  tag: latest

# Modify how DNS records are synchronised between sources and providers (default: sync, options: sync, upsert-only, create-only)
policy: sync

# provider needs to be set to plugin
provider: plugin

# url of the provider which the external-dns will target
extraArgs:
  plugin-provider-url: http://localhost:8888

# plugin is deployed as sidecar
sidecars:
  - name: ionos-plugin
    image: ghcr.io/ionos-cloud/external-dns-ionos-plugin:latest
    ports:
      - containerPort: 8888
        name: http
    livenessProbe:
      httpGet:
        path: /health
        port: http
      initialDelaySeconds: 10
      timeoutSeconds: 5
    readinessProbe:
      httpGet:
        path: /health
        port: http
      initialDelaySeconds: 10
      timeoutSeconds: 5
    env:
      # Set port of plugin (value needs to match the container port and plugin provider url port, default value: 8888)
      - name: SERVER_PORT
        value: "8888"
      # Listen on all interfaces for kubernetes probes
      - name: SERVER_HOST
        value: ""
      # Limit possible target zones by a domain suffix (optional)
      - name: DOMAIN_FILTER
        value: "example1.com,example2.com"
      # Exclude subdomains (optional)
      - name: EXCLUDE_DOMAIN_FILTER
        value: "example3.com"
      # Limit possible domains and target zones by a Regex filter. Overrides domain-filter (optional)
      - name: REGEXP_DOMAIN_FILTER
        value: ".*.example4.com"
      # Regex filter that excludes domains and target zones matched by regex-domain-filter (optional)
      - name: REGEXP_DOMAIN_FILTER_EXCLUSION
        value: ".*.example5.com"
      # When enabled, prints DNS record changes rather than actually performing them (default: false)
      - name: DRY_RUN
        value: "true"         
      # Token for DNSaaS rest API authentication (mandatory)  
      - name: IONOS_API_KEY
        value: "21215454"
      - name: LOG_LEVEL
        value: debug
      # When enabled debug logs for the DNSaaS rest API are enabled (default: false)  
      - name: IONOS_DEBUG
        value: "true"

Install ExternalDNS: To install ExternalDNS with Bitnami Helm chart, use the following commad:

helm install external-dns-ionos bitnami/external-dns -f external-dns-ionos-values.yaml

Deploy application: Follow this step to deploy an application:

Deploy an echo server application by using the file echoserver_app.yaml.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: echoserver
  namespace: echoserver
spec:
  replicas: 1
  selector:
    matchLabels:
      app: echoserver
  template:
    metadata:
      labels:
        app: echoserver
    spec:
      containers:
      - image: ealen/echo-server:latest
        imagePullPolicy: IfNotPresent
        name: echoserver
        ports:
        - containerPort: 80
        env:
        - name: PORT
          value: "80"
---
apiVersion: v1
kind: Service
metadata:
  name: echoserver
  namespace: echoserver
spec:
  ports:
    - port: 80
      targetPort: 80
      protocol: TCP
  type: ClusterIP
  selector:
    app: echoserver
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: echoserver
  namespace: echoserver
  annotations:
    kubernetes.io/ingress.class: nginx
spec:
  rules:
  - host: app.example1.com #This is your subdomain / record name
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: echoserver
            port:
              number: 80

kubectl apply -f echoserver_app.yaml

Result: The deployment of ExternalDNS on Managed Kubernetes is complete.

Verify deployment

You can verify that the application deployed is functioning as expected by using one of the following options.

Access application

Check that the echo server app runs on the subdomain you have specified by using the following command:

curl -I app.example1.com/?echo_code=404-300

Expected result:

HTTP/1.1 404 Not Found 
HTTP/1.1 300 Multiple Choices

Check DNS records

Check that the new A and TXT records are created by using the following command:

curl --location --request GET 'https://dns.de-fra.ionos.com/records?filter.name=app' \
--header 'Authorization: Bearer eyJ0eXAiOiJKV1QiLCJraWQiOiI4MmE5' \
--data ''

Set Up a Secondary Zone

This tutorial explains how to set up a secondary DNS zone in IONOS Cloud by running a bind9 server on an Ubuntu operating system. The setup includes the following configuration steps:

Set up a Dedicated Core server in IONOS Cloud.
Configure a primary nameserver on a Dedicated Core Server in IONOS Cloud running a bind9 server on an Ubuntu operating system.
Create a secondary DNS zone using IONOS Cloud DNS API.
Establish and verify the zone transfer between primary and secondary zones.

Set up a Dedicated Core Server in IONOS Cloud

Note:

The user who creates the server has full root or administrator access rights. A server, once provisioned, retains all its settings (resources, drive allocation, password, and so on), even after server restart at the operating system level.
The server will only be removed from your virtual data center once you delete it in the DCD.

To set up a Dedicated Core server in IONOS Cloud, follow these steps:

1. Create a Dedicated Core server and configure the server in the Settings tab by following the steps in Create a Dedicated Core Server.

2. Configure the server Network settings by following the steps in the Dedicated Core Server network settings.

3. Configure the server Storage settings by following the steps in the Dedicated Core Server storage settings.

4. Continue to provision the changes and start the Dedicated Core Server by following the steps in the Provision changes and starting the Dedicated Core Server.

Result: A Dedicated Core Server is set up and started along with the configuration of Settings, Network, and Storage setup.

Dedicated Core Server network settings

In the DCD > Inspector pane on the right, configure the following network details in the Network tab.

1. Name: Choose a name unique to this Virtual Data Center (VDC).

2. MAC: Assigned on VM creation.

3. LAN: Select the LAN connection that is connected to the internet, by default LAN 1.

4. Firewall: By default, the firewall is disabled. To enable firewall rules, make sure that incoming and outgoing traffic is allowed on port 53 for UDP and TCP.

5. IPv4 Configuration: Leave to default values.

Result: The Network settings for a Dedicated Core server are configured.

Dedicated Core Server storage settings

Warning: The storage type cannot be changed after provisioning.

In the DCD > Inspector pane on the right, configure the following storage details in the Storage tab.

1. Click SSD and a new pop-up window Create New Attached Storage appears.

2. Configure the following storage details:

Name: Enter a name that is unique within your VDC.
Availability Zone: Leave on "Auto".
Size in GB: Enter "30" which is sufficient for this tutorial.
Performance Select "Standard".
Image: You can select one of IONOS images or snapshots, or use your own. For this tutorial, we will use an Ubuntu server image from IONOS. To make the same choice, select ubuntu-22.04-server-cloudimg-amd64 under IONOS Images.
Password: Create a password for the "root" user of the server. You will need this password to SSH and make changes.
SSH Keys: Select an SSH key stored in the SSH Key Manager.
Ad-hoc SSH Key: If you have not created an SSH key, copy and paste the public part of your SSH key into this field.
Cloud-Init user data: Leave on "No configuration".
Boot from Device: Select this checkbox to make the SSD drive bootable.

3. Click Create SSD Storage to create the SSD storage.

Result: The Storage settings for a Dedicated Core server are configured.

Provision changes and start the Dedicated Core Server

1. Select the newly created Dedicated Core server.

2. From the Settings tab in the Inspector pane, select Power > Start.

3. Click Provision Changes in the lower right corner and further click Provision Now.

Result: The Dedicated Core server is provisioned and started.

Next steps: After your changes are provisioned and the server is started, select your Dedicated Core server, click the Network tab in the Inspector pane and copy the IPv4 address.

Configure a Dedicated Core Server as a primary nameserver

Prerequisite: A Dedicated Core server in IONOS Cloud needs to be set up and you must have the IPv4 address of the server.

To configure a Dedicated Core server and enable it to act as the primary nameserver, follow these steps:

1. SSH into the newly created Dedicated Core server.

ssh root@<IP-ADDRESS>

2. Connect to the newly created server via SSH.

root@ubuntu:~# sudo -i
root@ubuntu:~# apt update -y
[...]
root@ubuntu:~# apt install -y bind9 bind9utils
[...]

3. Proceed with configuring bind9 and your primary DNS zone.

root@ubuntu:~# vi /etc/bind/named.conf.local

4. Configure notify to the IONOS Cloud DNS anycast nameserver and allow zone update from localhost.

Note: For sending DNS notify messages, Cloud DNS uses the following Anycast addresses: IPv4 212.227.123.25 or IPv6 2001:8d8:fe:53::5cd:25.

logging {
  category xfer-out { default_syslog; };
  category xfer-in { default_syslog; };
  category notify { default_syslog; };
  category lame-servers { default_syslog; };
  category general { default_syslog; };
  category default { default_syslog; };
};


zone "primary-zone.de" IN {
  type master;
  file "/var/cache/bind/primary-zone.de.db";
  notify explicit;
  also-notify  { 212.227.123.25; };
  allow-update { 127.0.0.1; };
};

5. Create your primary zone.

root@ubuntu:~# vi /var/cache/bind/primary-zone.de.db

6. Edit the zone file.

; Zone: primary-zone.de
; Exported: Mon Aug 17 22:36:11 UTC 2023
 
$ORIGIN primary-zone.de.
$TTL 3600
 
@   3600    IN  SOA primary-zone.de. hostmaster.primary-zone.de. (
                    2017060104  ; serial
                    28800       ; refresh
                    7200        ; retry
                    604800      ; expire
                    600 )       ; minimum
@   3600    IN  NS  ns.ui-global-dns.com.
@   3600    IN  NS  ns.ui-global-dns.de.
@   3600    IN  NS  ns.ui-global-dns.org.
@   3600    IN  NS  ns.ui-global-dns.biz.
www 60    IN  A   127.0.0.1
www 60    IN  AAAA    ::1

7. Save your changes and quit the Vim editor.

8. Check the configuration, reload bind, and verify that the configured zone is working.

root@ubuntu:~# named-checkconf
root@ubuntu:~# systemctl reload named
root@ubuntu:~# dig +short primary-zone.de

Result: The Dedicated Core server is configured as the primary nameserver in IONOS Cloud running a bind9 server on an Ubuntu operating system.

Create a secondary zone in IONOS Cloud DNS

Prerequisite: A Dedicated Core server in IONOS Cloud is set up as a primary nameserver.

To create a secondary zone in the IONOS Cloud DNS by using the REST API, follow this step:

Send a POST request to the /secondaryzones endpoint.

curl --location 'https://dns.de-fra.ionos.com/secondaryzones' \
--header 'Content-Type: application/json' \
--header 'Authorization: Bearer eyJ0eXAiOiJKV1QiLCJraWQiO' \
--data '{
    "properties": {
        "zoneName": "primary-zone.de",
        "description": "This is a secondary zone for primary-zone.de in IONOS Cloud DNS",
        "primaryIps": [
            "<IP-ADDRESS>"
        ]
    }
}'

Response

{
    "id": "bdae7da0-0363-49d7-929d-92992786efe1",
    "type": "secondaryzone",
    "href": "/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1",
    "metadata": {
        "createdDate": "2023-08-06T19:36:58+00:00",
        "lastModifiedDate": "2023-08-06T19:36:59+00:00",
        "nameservers": [
            "nscs-ic.ui-dns.com",
            "nscs-ic.ui-dns.de",
            "nscs-ic.ui-dns.org",
            "nscs-ic.ui-dns.biz"
        ],
        "state": "AVAILABLE"
    },
    "properties": {
        "description": "This is a secondary zone for test-dns-public.info in IONOS Cloud DNS",
        "primaryIps": [
            "<IP-ADDRESS>"
        ],
        "zoneName": "test-dns-public.info"
    }
}

Result: A secondary zone in IONOS Cloud DNS is successfully created By using a POST request.

Verify zone transfer

On the primary nameserver, you can verify the zone transfer in the logs by executing the following command:

root@ubuntu:~# journalctl --unit named --follow
Aug 07 14:43:39 ubuntu named[2666]: client @0x7f467825b958 212.227.123.26#33308 (primary-zone.de): transfer of 'primary-zone.de/IN': AXFR started (serial 2017060104)
Aug 07 14:43:39 ubuntu named[2666]: client @0x7f467825b958 212.227.123.26#33308 (primary-zone.de): transfer of 'primary-zone.de/IN': AXFR ended: 1 messages, 8 records, 299 bytes, 0.001 secs (299000 bytes/sec) (serial 2017060104)

You can also verify zone transfer status using IONOS Cloud DNS API:

curl --location 'https://dns.de-fra.ionos.com/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1/axfr' \
--header 'Authorization: Bearer eyJ0eXAiOiJKV1QiLCJraWQiO'

Response

On success response: 200 OK

{
    "items": [
        {
            "errorMessage": "",
            "primaryIp": "<IP-ADDRESS>",
            "status": "OK"
        }
    ],
    "type": "collection"
}

Result: The zone transfer between primary and secondary zones is successfully verified.

Add a record

To add a record, follow these steps:

1. On the primary nameserver, update the zone with a new record setting—A record to a TEST-NET-3 IP address:

root@ubuntu:~# dig +short www. primary-zone.de @ns.ui-global-dns.com
217.160.0.148
root@ubuntu:~# nsupdate
> server 127.0.0.1
> zone primary-zone.de
> update add www2.primary-zone.de. 600 IN A 203.0.113.1
> send
> quit

2. Resolve the new record locally.

root@ubuntu:~# dig +short www2.primary-zone.de @127.0.0.1
203.0.113.1

3. View the logs which show that a notification is sent to the secondary zone for the new record.

Aug 07 16:00:22 ubuntu named[2666]: client @0x7f467000d0a8 127.0.0.1#34056: updating zone 'primary-zone.de/IN': adding an RR at 'www2.primary-zone.de' A 203.0.113.1
Aug 07 16:00:22 ubuntu named[2666]: zone primary-zone.de/IN: sending notifies (serial 2017060105)

4. Using Cloud DNS API, verify that the newly added record is transferred to the secondary zone.

curl --location 'https://dns.de-fra.ionos.com/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1/records' \
--header 'Authorization: Bearer eyJ0eXAiOiJKV1QiLCJraWQiO'

{
    "id": "bdae7da0-0363-49d7-929d-92992786efe1",
    "type": "collection",
    "href": "/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1/records?limit=100&offset=0",
    "metadata": {
        "primaryIps": [
            "<IP-ADDRESS>"
        ]
    },
    "items": [
        {
            "type": "record",
            "metadata": {
                "fqdn": "primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "primary-zone.de hostmaster.primary-zone.de 2017060105 28800 7200 604800 600",
                "enabled": true,
                "name": "",
                "priority": 0,
                "ttl": 3600,
                "type": "SOA"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "ns.ui-global-dns.de",
                "enabled": true,
                "name": "",
                "priority": 0,
                "ttl": 3600,
                "type": "NS"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "ns.ui-global-dns.biz",
                "enabled": true,
                "name": "",
                "priority": 0,
                "ttl": 3600,
                "type": "NS"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "ns.ui-global-dns.com",
                "enabled": true,
                "name": "",
                "priority": 0,
                "ttl": 3600,
                "type": "NS"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "ns.ui-global-dns.org",
                "enabled": true,
                "name": "",
                "priority": 0,
                "ttl": 3600,
                "type": "NS"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "www.primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "127.0.0.1",
                "enabled": true,
                "name": "www",
                "priority": 0,
                "ttl": 3600,
                "type": "A"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "www.primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "0:0:0:0:0:0:0:1",
                "enabled": true,
                "name": "www",
                "priority": 0,
                "ttl": 3600,
                "type": "AAAA"
            }
        },
        {
            "type": "record",
            "metadata": {
                "fqdn": "www2.primary-zone.de",
                "zoneId": "bdae7da0-0363-49d7-929d-92992786efe1",
                "rootName": "primary-zone.de"
            },
            "properties": {
                "content": "203.0.113.1",
                "enabled": true,
                "name": "www2",
                "priority": 0,
                "ttl": 3600,
                "type": "A"
            }
        }
    ],
    "offset": 0,
    "limit": 100,
    "_links": {
        "self": "/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1/records?limit=100&offset=0",
        "next": "/secondaryzones/bdae7da0-0363-49d7-929d-92992786efe1/records?limit=100&offset=100"
    }
}

5. Globally resolve a new record from the IONOS Cloud DNS anycast network by using the following command:

root@ubuntu:~# dig +short www2.primary-zone.de @ns.ui-global-dns.com.

Result: A record is successfully added to the primary nameserver.