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https://github.com/kubernetes-sigs/external-dns

Configure external DNS servers (AWS Route53, Google CloudDNS and others) for Kubernetes Ingresses and Services
https://github.com/kubernetes-sigs/external-dns

aws clouddns dns dns-controller dns-providers dns-record dns-servers external-dns gcp ingress k8s-sig-network kubernetes route53

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Configure external DNS servers (AWS Route53, Google CloudDNS and others) for Kubernetes Ingresses and Services

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	ExternalDNS




# ExternalDNS



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ExternalDNS synchronizes exposed Kubernetes Services and Ingresses with DNS providers.



## Documentation



This README is a part of the complete documentation, available [here](https://kubernetes-sigs.github.io/external-dns/).



## What It Does



Inspired by [Kubernetes DNS](https://github.com/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](https://kubernetes.io/docs/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](https://aws.amazon.com/route53/) or [Google Cloud DNS](https://cloud.google.com/dns/docs/).



In a broader sense, ExternalDNS allows you to control DNS records dynamically via Kubernetes resources in a DNS provider-agnostic way.



The [FAQ](docs/faq.md) contains additional information and addresses several questions about key concepts of ExternalDNS.



To see ExternalDNS in action, have a look at this [video](https://www.youtube.com/watch?v=9HQ2XgL9YVI) or read this [blogpost](https://codemine.be/posts/20190125-devops-eks-externaldns/).



## The Latest Release



ExternalDNS allows you to keep selected zones (via `--domain-filter`) synchronized with Ingresses and Services of `type=LoadBalancer` and nodes in various DNS providers:

* [Google Cloud DNS](https://cloud.google.com/dns/docs/)

* [AWS Route 53](https://aws.amazon.com/route53/)

* [AWS Cloud Map](https://docs.aws.amazon.com/cloud-map/)

* [AzureDNS](https://azure.microsoft.com/en-us/services/dns)

* [Civo](https://www.civo.com)

* [CloudFlare](https://www.cloudflare.com/dns)

* [DigitalOcean](https://www.digitalocean.com/products/networking)

* [DNSimple](https://dnsimple.com/)

* [OpenStack Designate](https://docs.openstack.org/designate/latest/)

* [PowerDNS](https://www.powerdns.com/)

* [CoreDNS](https://coredns.io/)

* [Exoscale](https://www.exoscale.com/dns/)

* [Oracle Cloud Infrastructure DNS](https://docs.cloud.oracle.com/iaas/Content/DNS/Concepts/dnszonemanagement.htm)

* [Linode DNS](https://www.linode.com/docs/networking/dns/)

* [RFC2136](https://tools.ietf.org/html/rfc2136)

* [NS1](https://ns1.com/)

* [TransIP](https://www.transip.eu/domain-name/)

* [OVH](https://www.ovh.com)

* [Scaleway](https://www.scaleway.com)

* [Akamai Edge DNS](https://learn.akamai.com/en-us/products/cloud_security/edge_dns.html)

* [GoDaddy](https://www.godaddy.com)

* [Gandi](https://www.gandi.net)

* [IBM Cloud DNS](https://www.ibm.com/cloud/dns)

* [TencentCloud PrivateDNS](https://cloud.tencent.com/product/privatedns)

* [TencentCloud DNSPod](https://cloud.tencent.com/product/cns)

* [Plural](https://www.plural.sh/)

* [Pi-hole](https://pi-hole.net/)



ExternalDNS is, by default, aware of the records it is managing, therefore it can safely manage non-empty hosted zones. We strongly encourage you to set `--txt-owner-id` to a unique value that doesn't change for the lifetime of your cluster. You might also want to run ExternalDNS in a dry run mode (`--dry-run` flag) to see the changes to be submitted to your DNS Provider API.



Note that all flags can be replaced with environment variables; for instance,

`--dry-run` could be replaced with `EXTERNAL_DNS_DRY_RUN=1`.



## New providers



No new provider will be added to ExternalDNS _in-tree_.



ExternalDNS has introduced a webhook system, which can be used to add a new provider.

See PR #3063 for all the discussions about it.



Known providers using webhooks:



| Provider              | Repo                                                                 |

|-----------------------|----------------------------------------------------------------------|

| Adguard Home Provider | https://github.com/muhlba91/external-dns-provider-adguard            |

| Anexia                | https://github.com/ProbstenHias/external-dns-anexia-webhook          |

| Bizfly Cloud          | https://github.com/bizflycloud/external-dns-bizflycloud-webhook      |

| Efficient IP          | https://github.com/EfficientIP-Labs/external-dns-efficientip-webhook |

| Gcore                 | https://github.com/G-Core/external-dns-gcore-webhook                 |

| GleSYS                | https://github.com/glesys/external-dns-glesys                        |

| Hetzner               | https://github.com/mconfalonieri/external-dns-hetzner-webhook        |

| Huawei Cloud          | https://github.com/setoru/external-dns-huaweicloud-webhook |

| IONOS                 | https://github.com/ionos-cloud/external-dns-ionos-webhook            |

| Infoblox              | https://github.com/AbsaOSS/external-dns-infoblox-webhook             |

| Mikrotik              | https://github.com/mirceanton/external-dns-provider-mikrotik         |

| Netcup                | https://github.com/mrueg/external-dns-netcup-webhook                 |

| Netic                 | https://github.com/neticdk/external-dns-tidydns-webhook              |

| RouterOS              | https://github.com/benfiola/external-dns-routeros-provider           |

| STACKIT               | https://github.com/stackitcloud/external-dns-stackit-webhook         |

| Unifi                 | https://github.com/kashalls/external-dns-unifi-webhook               |

| Vultr                 | https://github.com/vultr/external-dns-vultr-webhook                  |



## Status of in-tree providers



ExternalDNS supports multiple DNS providers which have been implemented by the [ExternalDNS contributors](https://github.com/kubernetes-sigs/external-dns/graphs/contributors). Maintaining all of those in a central repository is a challenge, which introduces lots of toil and potential risks.



This mean that `external-dns` has begun the process to move providers out of tree. See #4347 for more details. Those who are interested can create a webhook provider based on an _in-tree_ provider and after submit a PR to reference it here.



We define the following stability levels for providers:



- **Stable**: Used for smoke tests before a release, used in production and maintainers are active.

- **Beta**: Community supported, well tested, but maintainers have no access to resources to execute integration tests on the real platform and/or are not using it in production.

- **Alpha**: Community provided with no support from the maintainers apart from reviewing PRs.



The following table clarifies the current status of the providers according to the aforementioned stability levels:



| Provider | Status | Maintainers |

| -------- | ------ | ----------- |

| Google Cloud DNS | Stable | |

| AWS Route 53 | Stable | |

| AWS Cloud Map | Beta | |

| Akamai Edge DNS | Beta | |

| AzureDNS | Stable | |

| Civo | Alpha | @alejandrojnm |

| CloudFlare | Beta | |

| DigitalOcean | Alpha | |

| DNSimple | Alpha | |

| OpenStack Designate | Alpha | |

| PowerDNS | Alpha | |

| CoreDNS | Alpha | |

| Exoscale | Alpha | |

| Oracle Cloud Infrastructure DNS | Alpha | |

| Linode DNS | Alpha | |

| RFC2136 | Alpha | |

| NS1 | Alpha | |

| TransIP | Alpha | |

| OVH | Alpha | |

| Scaleway DNS | Alpha | @Sh4d1 |

| UltraDNS | Alpha | |

| GoDaddy | Alpha | |

| Gandi | Alpha | @packi |

| IBMCloud | Alpha | @hughhuangzh |

| TencentCloud | Alpha | @Hyzhou |

| Plural | Alpha | @michaeljguarino |

| Pi-hole | Alpha | @tinyzimmer |



## Kubernetes version compatibility



A [breaking change](https://github.com/kubernetes-sigs/external-dns/pull/2281) was added in external-dns v0.10.0.



| ExternalDNS                    |      <= 0.9.x      |     >= 0.10.0      |

| ------------------------------ | :----------------: | :----------------: |

| Kubernetes <= 1.18             | :white_check_mark: |        :x:         |

| Kubernetes >= 1.19 and <= 1.21 | :white_check_mark: | :white_check_mark: |

| Kubernetes >= 1.22             |        :x:         | :white_check_mark: |



## Running ExternalDNS:



The are two ways of running ExternalDNS:



* Deploying to a Cluster

* Running Locally



### Deploying to a Cluster



The following tutorials are provided:



* [Akamai Edge DNS](docs/tutorials/akamai-edgedns.md)

* [Alibaba Cloud](docs/tutorials/alibabacloud.md)

* AWS

	* [AWS Load Balancer Controller](docs/tutorials/aws-load-balancer-controller.md)

	* [Route53](docs/tutorials/aws.md)

		* [Same domain for public and private Route53 zones](docs/tutorials/aws-public-private-route53.md)

	* [Cloud Map](docs/tutorials/aws-sd.md)

	* [Kube Ingress AWS Controller](docs/tutorials/kube-ingress-aws.md)

* [Azure DNS](docs/tutorials/azure.md)

* [Azure Private DNS](docs/tutorials/azure-private-dns.md)

* [Civo](docs/tutorials/civo.md)

* [Cloudflare](docs/tutorials/cloudflare.md)

* [CoreDNS](docs/tutorials/coredns.md)

* [DigitalOcean](docs/tutorials/digitalocean.md)

* [DNSimple](docs/tutorials/dnsimple.md)

* [Exoscale](docs/tutorials/exoscale.md)

* [ExternalName Services](docs/tutorials/externalname.md)

* Google Kubernetes Engine

	* [Using Google's Default Ingress Controller](docs/tutorials/gke.md)

	* [Using the Nginx Ingress Controller](docs/tutorials/gke-nginx.md)

* [Headless Services](docs/tutorials/hostport.md)

* [Istio Gateway Source](docs/sources/istio.md)

* [Linode](docs/tutorials/linode.md)

* [NS1](docs/tutorials/ns1.md)

* [NS Record Creation with CRD Source](docs/sources/ns-record.md)

* [MX Record Creation with CRD Source](docs/sources/mx-record.md)

* [TXT Record Creation with CRD Source](docs/sources/txt-record.md)

* [OpenStack Designate](docs/tutorials/designate.md)

* [Oracle Cloud Infrastructure (OCI) DNS](docs/tutorials/oracle.md)

* [PowerDNS](docs/tutorials/pdns.md)

* [RFC2136](docs/tutorials/rfc2136.md)

* [TransIP](docs/tutorials/transip.md)

* [OVH](docs/tutorials/ovh.md)

* [Scaleway](docs/tutorials/scaleway.md)

* [UltraDNS](docs/tutorials/ultradns.md)

* [GoDaddy](docs/tutorials/godaddy.md)

* [Gandi](docs/tutorials/gandi.md)

* [IBM Cloud](docs/tutorials/ibmcloud.md)

* [Nodes as source](docs/sources/nodes.md)

* [TencentCloud](docs/tutorials/tencentcloud.md)

* [Plural](docs/tutorials/plural.md)

* [Pi-hole](docs/tutorials/pihole.md)



### Running Locally



See the [contributor guide](docs/contributing/getting-started.md) for details on compiling

from source.



#### Setup Steps



Next, run an application and expose it via a Kubernetes Service:



```console

kubectl run nginx --image=nginx --port=80

kubectl expose pod nginx --port=80 --target-port=80 --type=LoadBalancer

```



Annotate the Service with your desired external DNS name. Make sure to change `example.org` to your domain.



```console

kubectl annotate service nginx "external-dns.alpha.kubernetes.io/hostname=nginx.example.org."

```



Optionally, you can customize the TTL value of the resulting DNS record by using the `external-dns.alpha.kubernetes.io/ttl` annotation:



```console

kubectl annotate service nginx "external-dns.alpha.kubernetes.io/ttl=10"

```



For more details on configuring TTL, see [here](docs/ttl.md).



Use the internal-hostname annotation to create DNS records with ClusterIP as the target.



```console

kubectl annotate service nginx "external-dns.alpha.kubernetes.io/internal-hostname=nginx.internal.example.org."

```



If the service is not of type Loadbalancer you need the --publish-internal-services flag.



Locally run a single sync loop of ExternalDNS.



```console

external-dns --txt-owner-id my-cluster-id --provider google --google-project example-project --source service --once --dry-run

```



This should output the DNS records it will modify to match the managed zone with the DNS records you desire. It also assumes you are running in the `default` namespace. See the [FAQ](docs/faq.md) for more information regarding namespaces.



Note: TXT records will have the `my-cluster-id` value embedded. Those are used to ensure that ExternalDNS is aware of the records it manages.



Once you're satisfied with the result, you can run ExternalDNS like you would run it in your cluster: as a control loop, and **not in dry-run** mode:



```console

external-dns --txt-owner-id my-cluster-id --provider google --google-project example-project --source service

```



Check that ExternalDNS has created the desired DNS record for your Service and that it points to its load balancer's IP. Then try to resolve it:



```console

dig +short nginx.example.org.

104.155.60.49

```



Now you can experiment and watch how ExternalDNS makes sure that your DNS records are configured as desired. Here are a couple of things you can try out:

* Change the desired hostname by modifying the Service's annotation.

* Recreate the Service and see that the DNS record will be updated to point to the new load balancer IP.

* Add another Service to create more DNS records.

* Remove Services to clean up your managed zone.



The **tutorials** section contains examples, including Ingress resources, and shows you how to set up ExternalDNS in different environments such as other cloud providers and alternative Ingress controllers.



# Note



If using a txt registry and attempting to use a CNAME the `--txt-prefix` must be set to avoid conflicts.  Changing `--txt-prefix` will result in lost ownership over previously created records.



If `externalIPs` list is defined for a `LoadBalancer` service, this list will be used instead of an assigned load balancer IP to create a DNS record. It's useful when you run bare metal Kubernetes clusters behind NAT or in a similar setup, where a load balancer IP differs from a public IP (e.g. with [MetalLB](https://metallb.universe.tf)).



## Contributing



Are you interested in contributing to external-dns? We, the maintainers and community, would love your

suggestions, contributions, and help! Also, the maintainers can be contacted at any time to learn more

about how to get involved.



We also encourage ALL active community participants to act as if they are maintainers, even if you don't have

"official" write permissions. This is a community effort, we are here to serve the Kubernetes community. If you

have an active interest and you want to get involved, you have real power! Don't assume that the only people who

can get things done around here are the "maintainers". We also would love to add more "official" maintainers, so

show us what you can do!



The external-dns project is currently in need of maintainers for specific DNS providers. Ideally each provider

would have at least two maintainers. It would be nice if the maintainers run the provider in production, but it

is not strictly required. Provider listed [here](https://github.com/kubernetes-sigs/external-dns#status-of-in-tree-providers)

that do not have a maintainer listed are in need of assistance.



Read the [contributing guidelines](CONTRIBUTING.md) and have a look at [the contributing docs](docs/contributing/getting-started.md) to learn about building the project, the project structure, and the purpose of each package.



For an overview on how to write new Sources and Providers check out [Sources and Providers](docs/contributing/sources-and-providers.md).



## Heritage



ExternalDNS is an effort to unify the following similar projects in order to bring the Kubernetes community an easy and predictable way of managing DNS records across cloud providers based on their Kubernetes resources:



* Kops' [DNS Controller](https://github.com/kubernetes/kops/tree/HEAD/dns-controller)

* Zalando's [Mate](https://github.com/linki/mate)

* Molecule Software's [route53-kubernetes](https://github.com/wearemolecule/route53-kubernetes)



### User Demo How-To Blogs and Examples



* A full demo on GKE Kubernetes. See [How-to Kubernetes with DNS management (ssl-manager pre-req)](https://medium.com/@jpantjsoha/how-to-kubernetes-with-dns-management-for-gitops-31239ea75d8d)

* Run external-dns on GKE with workload identity. See [Kubernetes, ingress-nginx, cert-manager & external-dns](https://blog.atomist.com/kubernetes-ingress-nginx-cert-manager-external-dns/)

* [ExternalDNS integration with Azure DNS using workload identity](https://cloudchronicles.blog/blog/ExternalDNS-integration-with-Azure-DNS-using-workload-identity/)