[bitnami/redis] Enables Redis to utilize external-dns

bitnami/redis/Chart.yaml

@@ -24,5 +24,4 @@ maintainers:
 name: redis
 sources:
   - https://github.com/bitnami/bitnami-docker-redis
-  - http://redis.io/
-version: 16.0.1
+version: 16.1.0

bitnami/redis/README.md

@@ -458,6 +458,16 @@ The command removes all the Kubernetes components associated with the chart and
 | `sysctl.resources.requests`                            | The requested resources for the init container                                                  | `{}`                    |
 
 
+### useExternalDNS Parameters
+
+| Name                                   | Description                                                                                                                              | Value                               |
+| -------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------- |
+| `useExternalDNS.enabled`               | Enable various syntax that would enable external-dns to work.  Note this requires a working installation of `external-dns` to be usable. | `false`                             |
+| `useExternalDNS.additionalAnnotations` | Extra annotations to be utilized when `external-dns` is enabled.                                                                         | `{}`                                |
+| `useExternalDNS.annotationKey`         | The annotation key utilized when `external-dns` is enabled.                                                                              | `external-dns.alpha.kubernetes.io/` |
+| `useExternalDNS.suffix`                | The DNS suffix utilized when `external-dns` is enabled.  Note that we prepend the suffix with the full name of the release.              | `""`                                |
+
+
 Specify each parameter using the `--set key=value[,key=value]` argument to `helm install`. For example,
 
 ```bash
@@ -490,6 +500,30 @@ Bitnami will release a new chart updating its containers if a new version of the
 
 To modify the application version used in this chart, specify a different version of the image using the `image.tag` parameter and/or a different repository using the `image.repository` parameter. Refer to the [chart documentation for more information on these parameters and how to use them with images from a private registry](https://docs.bitnami.com/kubernetes/infrastructure/redis/configuration/change-image-version/).
 
+### External DNS
+
+This chart is equipped to allow leveraging the ExternalDNS project. Doing so will enable ExternalDNS to publish the FQDN for each instance, in the format of `<pod-name>.<release-name>.<dns-suffix>`.
+Example, when using the following configuration:
+
+```yaml
+useExternalDNS:
+  enabled: true
+  suffix: prod.example.org
+  additionalAnnotations:
+    ttl: 10
+```
+
+On a cluster where the name of the Helm release is `a`, the hostname of a Pod is generated as: `a-redis-node-0.a-redis.prod.example.org`. The IP of that FQDN will match that of the associated Pod. This modifies the following parameters of the Redis/Sentinel configuration using this new FQDN:
+
+* `replica-announce-ip`
+* `known-sentinel`
+* `known-replica`
+* `announce-ip`
+
+:warning: This requires a working installation of `external-dns` to be fully functional. :warning:
+
+See the [official ExternalDNS documentation](https://github.com/kubernetes-sigs/external-dns) for additional configuration options.
+
 ### Cluster topologies
 
 #### Default: Master-Replicas

bitnami/redis/templates/_helpers.tpl

@@ -274,3 +274,18 @@ redis: tls.enabled
     enable auto-generated certificates.
 {{- end -}}
 {{- end -}}
+
+{{/* Define the suffix utilized for external-dns */}}
+{{- define "redis.externalDNS.suffix" -}}
+{{ printf "%s.%s" (include "common.names.fullname" .) .Values.useExternalDNS.suffix }}
+{{- end -}}
+
+{{/* Compile all annotations utilized for external-dns */}}
+{{- define "redis.externalDNS.annotations" -}}
+{{- if .Values.useExternalDNS.enabled }}
+{{ .Values.useExternalDNS.annotationKey }}hostname: {{ include "redis.externalDNS.suffix" . }}
+{{- range $key, $val := .Values.useExternalDNS.additionalAnnotations }}
+{{ $.Values.useExternalDNS.annotationKey }}{{ $key }}: {{ $val | quote }}
+{{- end }}
+{{- end }}
+{{- end }}

bitnami/redis/templates/headless-svc.yaml

@@ -7,9 +7,11 @@ metadata:
     {{- if .Values.commonLabels }}
     {{- include "common.tplvalues.render" ( dict "value" .Values.commonLabels "context" $ ) | nindent 4 }}
     {{- end }}
+  annotations:
   {{- if .Values.commonAnnotations }}
-  annotations: {{- include "common.tplvalues.render" ( dict "value" .Values.commonAnnotations "context" $ ) | nindent 4 }}
+  {{- include "common.tplvalues.render" ( dict "value" .Values.commonAnnotations "context" $ ) | nindent 4 }}
   {{- end }}
+  {{- include "redis.externalDNS.annotations" . | nindent 4 }}
 spec:
   type: ClusterIP
   clusterIP: None

bitnami/redis/templates/scripts-configmap.yaml

@@ -43,7 +43,9 @@ data:
     get_full_hostname() {
         hostname="$1"
 
-        {{- if eq .Values.sentinel.service.type "NodePort" }}
+        {{- if .Values.useExternalDNS.enabled }}
+        echo "${hostname}.{{- include "redis.externalDNS.suffix" . }}"
+        {{- else if eq .Values.sentinel.service.type "NodePort" }}
         echo "${hostname}.{{- .Release.Namespace }}"
         {{- else }}
         echo "${hostname}.${HEADLESS_SERVICE}"
@@ -232,7 +234,9 @@ data:
     get_full_hostname() {
         hostname="$1"
 
-        {{- if eq .Values.sentinel.service.type "NodePort" }}
+        {{- if .Values.useExternalDNS.enabled }}
+        echo "${hostname}.{{- include "redis.externalDNS.suffix" . }}"
+        {{- else if eq .Values.sentinel.service.type "NodePort" }}
         echo "${hostname}.{{- .Release.Namespace }}"
         {{- else }}
         echo "${hostname}.${HEADLESS_SERVICE}"
@@ -361,7 +365,9 @@ data:
     get_full_hostname() {
         hostname="$1"
 
-        {{- if eq .Values.sentinel.service.type "NodePort" }}
+        {{- if .Values.useExternalDNS.enabled }}
+        echo "${hostname}.{{- include "redis.externalDNS.suffix" . }}"
+        {{- else if eq .Values.sentinel.service.type "NodePort" }}
         echo "${hostname}.{{- .Release.Namespace }}"
         {{- else }}
         echo "${hostname}.${HEADLESS_SERVICE}"
@@ -506,7 +512,9 @@ data:
     get_full_hostname() {
         hostname="$1"
 
-        {{- if eq .Values.sentinel.service.type "NodePort" }}
+        {{- if .Values.useExternalDNS.enabled }}
+        echo "${hostname}.{{- include "redis.externalDNS.suffix" . }}"
+        {{- else if eq .Values.sentinel.service.type "NodePort" }}
         echo "${hostname}.{{- .Release.Namespace }}"
         {{- else }}
         echo "${hostname}.${HEADLESS_SERVICE}"

bitnami/redis/values.yaml

@@ -1448,3 +1448,16 @@ sysctl:
   resources:
     limits: {}
     requests: {}
+
+## @section useExternalDNS Parameters
+##
+## @param useExternalDNS.enabled Enable various syntax that would enable external-dns to work.  Note this requires a working installation of `external-dns` to be usable.
+## @param useExternalDNS.additionalAnnotations Extra annotations to be utilized when `external-dns` is enabled.
+## @param useExternalDNS.annotationKey The annotation key utilized when `external-dns` is enabled.
+## @param useExternalDNS.suffix The DNS suffix utilized when `external-dns` is enabled.  Note that we prepend the suffix with the full name of the release.
+##
+useExternalDNS:
+  enabled: false
+  suffix: ""
+  annotationKey: external-dns.alpha.kubernetes.io/
+  additionalAnnotations: {}