Files
charts/upstreamed/external-dns

external-dns

ExternalDNS is a Kubernetes addon that configures public DNS servers with information about exposed Kubernetes services to make them discoverable.

TL;DR;

$ helm install stable/external-dns

Introduction

This chart bootstraps a ExternalDNS deployment on a Kubernetes cluster using the Helm package manager.

Bitnami charts can be used with Kubeapps for deployment and management of Helm Charts in clusters. This chart has been tested to work with NGINX Ingress, cert-manager, fluentd and Prometheus on top of the BKPR.

Prerequisites

  • Kubernetes 1.8+ with Beta APIs enabled

Installing the Chart

To install the chart with the release name my-release:

$ helm install --name my-release stable/external-dns

The command deploys ExternalDNS on the Kubernetes cluster in the default configuration. The configuration section lists the parameters that can be configured during installation.

Tip

: List all releases using helm list

Uninstalling the Chart

To uninstall/delete the my-release deployment:

$ helm delete my-release

The command removes all the Kubernetes components associated with the chart and deletes the release.

Configuration

The following table lists the configurable parameters of the external-dns chart and their default values.

Parameter Description Default
global.imageRegistry Global Docker image registry nil
global.imagePullSecrets Global Docker registry secret names as an array [] (does not add image pull secrets to deployed pods)
image.registry ExternalDNS image registry docker.io
image.repository ExternalDNS Image name bitnami/external-dns
image.tag ExternalDNS Image tag {TAG_NAME}
image.pullPolicy ExternalDNS image pull policy IfNotPresent
image.pullSecrets Specify docker-registry secret names as an array [] (does not add image pull secrets to deployed pods)
nameOverride String to partially override external-dns.fullname template with a string (will prepend the release name) nil
fullnameOverride String to fully override external-dns.fullname template with a string nil
sources K8s resources type to be observed for new DNS entries by ExternalDNS [service, ingress]
provider DNS provider where the DNS records will be created (mandatory) (options: aws, azure, google, ...) aws
publishInternalServices Whether to publish DNS records for ClusterIP services or not false
aws.credentials.accessKey When using the AWS provider, set aws_access_key_id in the AWS credentials (optional) ""
aws.credentials.secretKey When using the AWS provider, set aws_secret_access_key in the AWS credentials (optional) ""
aws.credentials.mountPath When using the AWS provider, determine mountPath for credentials secret "/.aws"
aws.region When using the AWS provider, AWS_DEFAULT_REGION to set in the environment (optional) us-east-1
aws.zoneType When using the AWS provider, filter for zones of this type (optional, options: public, private) ""
aws.assumeRoleArn When using the AWS provider, assume role by specifying --aws-assume-role to the external-dns daemon ""
aws.batchChangeSize When using the AWS provider, set the maximum number of changes that will be applied in each batch 1000
aws.zoneTags When using the AWS provider, filter for zones with these tags []
azure.secretName When using the Azure provider, set the secret containing the azure.json file ""
azure.resourceGroup When using the Azure provider, set the Azure Resource Group ""
cloudflare.apiKey When using the Cloudflare provider, CF_API_KEY to set (optional) ""
cloudflare.email When using the Cloudflare provider, CF_API_EMAIL to set (optional) ""
cloudflare.proxied When using the Cloudflare provider, enable the proxy feature (DDOS protection, CDN...) (optional) true
coredns.etcdEndpoints When using the CoreDNS provider, set etcd backend endpoints (comma-separated list) "http://etcd-extdns:2379"
coredns.etcdTLS.enabled When using the CoreDNS provider, enable secure communication with etcd false
coredns.etcdTLS.secretName When using the CoreDNS provider, specify a name of existing Secret with etcd certs and keys "etcd-client-certs"
coredns.etcdTLS.mountPath When using the CoreDNS provider, set destination dir to mount data from coredns.etcdTLS.secretName to "/etc/coredns/tls/etcd"
coredns.etcdTLS.caFilename When using the CoreDNS provider, specify CA PEM file name from the coredns.etcdTLS.secretName "ca.crt"
coredns.etcdTLS.certFilename When using the CoreDNS provider, specify cert PEM file name from the coredns.etcdTLS.secretName "cert.pem"
coredns.etcdTLS.keyFilename When using the CoreDNS provider, specify private key PEM file name from the coredns.etcdTLS.secretName "key.pem"
designate.customCA.enabled When using the Designate provider, enable a custom CA (optional) false
designate.customCA.content When using the Designate provider, set the content of the custom CA ""
designate.customCA.mountPath When using the Designate provider, set the mountPath in which to mount the custom CA configuration "/config/designate"
designate.customCA.filename When using the Designate provider, set the custom CA configuration filename "designate-ca.pem"
digitalocean.apiToken When using the DigitalOcean provider, DO_TOKEN to set (optional) ""
google.project When using the Google provider, specify the Google project (required when provider=google) ""
google.serviceAccountSecret When using the Google provider, specify the existing secret which contains credentials.json (optional) ""
google.serviceAccountKey When using the Google provider, specify the service account key JSON file. (required when google.serviceAccountSecret is not provided. In this case a new secret will be created holding this service account ""
infoblox.gridHost When using the Infoblox provider, specify the Infoblox Grid host (required when provider=infoblox) ""
infoblox.wapiUsername When using the Infoblox provider, specify the Infoblox WAPI username "admin"
infoblox.wapiPassword When using the Infoblox provider, specify the Infoblox WAPI password (required when provider=infoblox) ""
infoblox.domainFilter When using the Infoblox provider, specify the domain (optional) ""
infoblox.noSslVerify When using the Infoblox provider, disable SSL verification (optional) false
infoblox.wapiPort When using the Infoblox provider, specify the Infoblox WAPI port (optional) ""
infoblox.wapiVersion When using the Infoblox provider, specify the Infoblox WAPI version (optional) ""
infoblox.wapiConnectionPoolSize When using the Infoblox provider, specify the Infoblox WAPI request connection pool size (optional) ""
infoblox.wapiHttpTimeout When using the Infoblox provider, specify the Infoblox WAPI request timeout in seconds (optional) ""
rfc2136.host When using the rfc2136 provider, specify the RFC2136 host (required when provider=rfc2136) ""
rfc2136.port When using the rfc2136 provider, specify the RFC2136 port (optional) 53
rfc2136.zone When using the rfc2136 provider, specify the zone (required when provider=rfc2136) ""
rfc2136.tsigSecret When using the rfc2136 provider, specify the tsig secret to enable security (optional) ""
rfc2136.tsigKeyname When using the rfc2136 provider, specify the tsig keyname to enable security (optional) "externaldns-key"
rfc2136.tsigSecretAlg When using the rfc2136 provider, specify the tsig secret to enable security (optional) "hmac-sha256"
rfc2136.tsigAxfr When using the rfc2136 provider, enable AFXR to enable security (optional) true
pdns.apiUrl When using the PowerDNS provider, specify the API URL of the server. ""
pdns.apiPort When using the PowerDNS provider, specify the API port of the server. 8081
pdns.apiKey When using the PowerDNS provider, specify the API key of the server. ""
annotationFilter Filter sources managed by external-dns via annotation using label selector (optional) ""
domainFilters Limit possible target zones by domain suffixes (optional) []
zoneIdFilters Limit possible target zones by zone id (optional) []
crd.create If true, create CRD ressource false
crd.apiversion Sets the API version for the CRD to watch "
crd.kind Sets the kind for the CRD to watch "
dryRun When enabled, prints DNS record changes rather than actually performing them (optional) false
logLevel Verbosity of the logs (options: panic, debug, info, warn, error, fatal) info
interval Interval update period to use 1m
istioIngressGateways The fully-qualified name of the Istio ingress gateway services . ""
policy Modify how DNS records are sychronized between sources and providers (options: sync, upsert-only ) upsert-only
registry Registry method to use (options: txt, noop) txt
txtOwnerId When using the TXT registry, a name that identifies this instance of ExternalDNS (optional) "default"
txtPrefix When using the TXT registry, a prefix for ownership records that avoids collision with CNAME entries (optional) ""
extraArgs Extra arguments to be passed to external-dns {}
extraEnv Extra environment variables to be passed to external-dns []
replicas Desired number of ExternalDNS replicas 1
affinity Affinity for pod assignment (this value is evaluated as a template) {}
nodeSelector Node labels for pod assignment (this value is evaluated as a template) {}
tolerations Tolerations for pod assignment (this value is evaluated as a template) []
podAnnotations Additional annotations to apply to the pod. {}
podLabels Additional labels to be added to pods {}
podSecurityContext.fsGroup Group ID for the container 1001
podSecurityContext.runAsUser User ID for the container 1001
priorityClassName priorityClassName ""
securityContext Security context for the container {}
service.type Kubernetes Service type ClusterIP
service.port ExternalDNS client port 7979
service.nodePort Port to bind to for NodePort service type (client port) nil
service.clusterIP IP address to assign to service ""
service.externalIPs Service external IP addresses []
service.loadBalancerIP IP address to assign to load balancer (if supported) ""
service.loadBalancerSourceRanges List of IP CIDRs allowed access to load balancer (if supported) []
service.annotations Annotations to add to service {}
rbac.create Wether to create & use RBAC resources or not false
rbac.serviceAccountName ServiceAccount (ignored if rbac.create == true) default
rbac.apiVersion Version of the RBAC API v1beta1
rbac.pspEnabled PodSecurityPolicy false
resources CPU/Memory resource requests/limits. {}
livenessProbe Deployment Liveness Probe See values.yaml
readinessProbe Deployment Readiness Probe See values.yaml
metrics.enabled Enable prometheus to access external-dns metrics endpoint false
metrics.podAnnotations Annotations for enabling prometheus to access the metrics endpoint {prometheus.io/scrape: "true",prometheus.io/port: "7979"}

Specify each parameter using the --set key=value[,key=value] argument to helm install. For example,

$ helm install --name my-release \
  --set provider=aws stable/external-dns

Alternatively, a YAML file that specifies the values for the parameters can be provided while installing the chart. For example,

$ helm install --name my-release -f values.yaml stable/external-dns

Tip

: You can use the default values.yaml

Production configuration

This chart includes a values-production.yaml file where you can find some parameters oriented to production configuration in comparison to the regular values.yaml.

$ helm install --name my-release -f ./values-production.yaml stable/external-dns
  • Desired number of ExternalDNS replicas:
- replicas: 1
+ replicas: 3
  • Enable prometheus to access external-dns metrics endpoint:
- metrics.enabled: false
+ metrics.enabled: true

Tutorials

Find information about the requirements for each DNS provider on the link below:

For instance, to install ExternalDNS on AWS, you need to:

  • Provide the K8s worker node which runs the cluster autoscaler with a minimum IAM policy (check IAM permissions docs for more information).
  • Setup a hosted zone on Route53 and annotate the Hosted Zone ID and its associated "nameservers" as described on these docs.
  • Install ExternalDNS chart using the command below:

Note: replace the placeholder HOSTED_ZONE_IDENTIFIER and HOSTED_ZONE_NAME, with your hosted zoned identifier and name, respectively.

$ helm install --name my-release \
  --set provider=aws \
  --set aws.zoneType=public \
  --set txtOwnerId=HOSTED_ZONE_IDENTIFIER \
  --set domainFilters[0]=HOSTED_ZONE_NAME \
  stable/external-dns

Rolling VS Immutable tags

It is strongly recommended to use immutable tags in a production environment. This ensures your deployment does not change automatically if the same tag is updated with a different image.

Bitnami will release a new chart updating its containers if a new version of the main container, significant changes, or critical vulnerabilities exist.

Upgrading

To 2.0.0

Backwards compatibility is not guaranteed unless you modify the labels used on the chart's deployments. Use the workaround below to upgrade from versions previous to 1.0.0. The following example assumes that the release name is my-release:

$ kubectl delete deployment my-release-external-dns
$ helm upgrade my-release stable/external-dns

Other mayor changes included in this major version are:

  • Default image changes from registry.opensource.zalan.do/teapot/external-dns to bitnami/external-dns.
  • The parameters below are renamed:
    • aws.secretKey -> aws.credentials.secretKey
    • aws.accessKey -> aws.credentials.accessKey
    • aws.credentialsPath -> aws.credentials.mountPath
    • designate.customCA.directory -> designate.customCA.mountPath
  • Support to Prometheus metrics is added.