Dynamic DNS

The Dynamic DNS service provides a unified, federation-wide Dynamic DNS support for VMs in EGI infrastructure. Users can register their chosen meaningful and memorable DNS hostnames in given domains (e.g. my-server.vo.fedcloud.eu) and assign to public IPs of their servers.

By using Dynamic DNS, users can host services in EGI Cloud with their meaningful service names, can freely move VMs from sites to sites without modifying server/client configurations (federated approach), can request valid server certificates in advance (critical for security) and many other advantages.

A short demonstration video is available at fedcloud.eu YouTube channel.

Dynamic DNS GUI portal

The Dynamic DNS offers a web GUI portal where users can login using their Check-in credentials. For doing so, click on the Login link (top left) and then click on the egi button.

Once logged in, you will be presented with the following page:

To register a new DNS host name:

1. Click on Overview and then on Add Host.

2. Type in the hostname you’d like to register and select the domain to use.

   

3. The portal will then show you a secret than can be used for updating the host ip whenever needed. Note it down so you can use it later.

4. From the VM you’d like to assign the name to, run a command like follows:

   curl "https://<hostname>:<secret>@nsupdate.fedcloud.eu/nic/update"
   

   where <hostname> is the full hostname generated before, e.g. myserver.fedcloud-tf.fedcloud.eu and <secret> is the secret generated in the previous step. You can add that as a boot command in your cloud-init configuration:

   #cloud-config
   
   runcmd:
     - [curl, "https://<hostname>:<secret>@nsupdate.fedcloud.eu/nic/update"]
   

5. You can also manually edit your registered hostnames in the Overview menu by clicking on the hostname you’d like to manage

Dynamic DNS support in Infrastructure Manager

Infrastructure Manager (IM) automatically creates hostname and assign the correct public IP of the head node of your infrastructure in the Dynamic DNS. Just fill in the DNS name to be used for the VM or DNS name to set to the Kubernetes Front-end (other infrastructures may have similar names for this field) with a FQDN within the supported domains of the Dynamic DNS:

IM will take care of registering the hostname, assigning the IP and eventually removing the hostname once the infrastructure is destroyed.

Wildcard hosts

For some use cases, it’s convenient for all hosts within a given subdomain to resolve to the same IP. For example, if the hostname of the head node of a kubernetes cluster is kubernetes.fedcloud.eu, all services on the cluster can have the same IP (e.g. dashboard.kubernetes.fedcloud.eu, api.kubernetes.fedcloud.eu, app1.kubernetes.fedcloud.eu), so the routing of the requests is managed at the cluster level by using an ingress or gateway object.

This kind of names can be registered using the API calls as described below.

API

List domains

List available domains for your user:

GET /nic/domains
Authorization: Bearer {{access_token}}

where access_token is a valid Check-in access token.

Sample response:

{
  "status": "ok",
  "private": [],
  "public": [
    {
      "name": "cloud.ai4eosc.eu",
      "public": true,
      "available": true,
      "comment": "Domain for stable services in AI4EOSC project",
      "owner": "viet02"
    },
    {
      "name": "cloud.eosc-siesta.eu",
      "public": true,
      "available": true,
      "comment": "Domain for production services in EOSC-SIESTA project",
      "owner": "root"
    },
}

Register host

You can register a new hostname with a call to /nic/register either by:

• specifying name and domain (both mandatory):

  GET /nic/register?name={{host_name}}&domain={{domain}}&comment={{comment}}&wildcard={{true|false|1|0|yes|no}}
  Authorization: Bearer {{access_token}}
  

  where:

  • host_name is the name of the host to register
  • domain is the domain where to register the host
  • comment is a comment to add to the host
  • wildcard is whether this is a wildcard name or not (default false)
  • access_token is a valid Check-in access token

• or by specifying the fqdn (also mandatory):

  GET /nic/register?fqdn={{fqdn_of_host}}&comment={{comment}}&wildcard={{true|false|1|0|yes|no}}
  Authorization: Bearer {{access_token}}
  

  where:

  • fqdn_of_host is fqdn of the host to register
  • comment is a comment to add to the host
  • wildcard is whether this is a wildcard name or not (default false)
  • access_token is a valid Check-in access token

Response will be a json as follows:

{
  "status": "ok",
  "message": "Host registered.",
  "host": {
    "fqdn": "test.vm.fedcloud.eu",
    "name": "test",
    "domain": "vm.fedcloud.eu",
    "wildcard": false,
    "comment": "test",
    "available": true,
    "client_faults": 0,
    "server_faults": 0,
    "abuse_blocked": false,
    "abuse": false,
    "last_update_ipv4": "2025-10-13T11:24:51.165433+00:00",
    "tls_update_ipv4": false,
    "ipv4": "10.10.0.253",
    "last_update_ipv6": null,
    "tls_update_ipv6": false,
    "ipv6": null,
    "update_secret": "some_secret",
    "IPv4_update_url_basic_auth": "https://test.vm.fedcloud.eu:some_secret@nsupdate.fedcloud.eu/nic/update",
    "IPv4_update_url_bearer_auth": "https://nsupdate.fedcloud.eu/nic/update?hostname=test.vm.fedcloud.eu&myip=${myip}"
  }
}

Update DNS record

Dynamic DNS update server uses dyndns2 protocol, compatible with commercial providers like dyn.com, and noip.com. The API is specified as follows:

GET /nic/update?hostname=yourhostname&myip=ipaddress
Host: nsupdate.fedcloud.eu
Authorization: Basic base64-encoded-auth-string
User-Agent:

where:

• base64-encoded-auth-string: base64 encoding of username:password
• username: your hostname
• password: your host secret
• hostname in the parameter string can be omitted or must be the same as username
• myip in the parameter string if omitted, the IP address of the client performing the GET request will be used

Lists hosts

This API lists all the registered hosts by a given user:

GET /nic/hosts
Authorization: Bearer {{access_token}}

or:

GET /nic/hosts?domain={{domain}}
Authorization: Bearer {{access_token}}

where:

• domain is the domain to list hosts for
• access_token is a valid Check-in access token

Sample response:

{
  "status": "ok",
  "hosts": [
    {
      "fqdn": "myhost.cloud.ai4eosc.eu",
      "name": "myhost",
      "domain": "cloud.ai4eosc.eu",
      "wildcard": false,
      "comment": "comment",
      "available": true,
      "client_faults": 1,
      "server_faults": 0,
      "abuse_blocked": false,
      "abuse": false,
      "last_update_ipv4": "2025-04-10T10:33:06.930760+00:00",
      "tls_update_ipv4": false,
      "ipv4": "147.213.65.206",
      "last_update_ipv6": "2025-04-10T10:21:57.975176+00:00",
      "tls_update_ipv6": false,
      "ipv6": null
    }
  ]
}

Security

• For updating IP address, only hostname and its secret are needed. No user information is stored on VM in any form for updating IP.

• NS-update server uses HTTPS protocol, hostname/secret are encrypted as data and not visible during transfer so it is secure to use the update URL

• NS-update portal does not store host secret in recoverable form. If you forget the secret of your hostname, simply generate new one via “Show configuration” button in the host edit page. The old secret will be invalid.

Support

Support for Dynamic DNS service is provided via EGI Helpdesk “Dynamic DNS” support unit, where users can ask questions, report issues or make requests for additional domains for specific projects or user communities.