fix(chart): Change .extraContainers type to array (#5564)

* fix(chart): Change .extraContainers type to array

Adding additional containers was impossible because the
`.extraContainers` attribute was defined as object while the templating
expected an array. This blocked the addition of other containers to the
deployment using the Helm chart.

Signed-off-by: Sven Greb <development@svengreb.de>

* fix(chart): Add changelog entry

Signed-off-by: Sven Greb <development@svengreb.de>

---------

Signed-off-by: Sven Greb <development@svengreb.de>

charts/external-dns/CHANGELOG.md

@@ -22,6 +22,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Update RBAC for `Service` source to support `EndpointSlices`. ([#5493](https://github.com/kubernetes-sigs/external-dns/pull/5493)) _@vflaux_
 
+### Fixed
+
+- Fixed the type of `.extraContainers` from `object` to `list` (array). ([#5564](https://github.com/kubernetes-sigs/external-dns/pull/5564)) _@svengreb_
+
 ## [v1.17.0] - 2025-06-04
 
 ### Changed

charts/external-dns/README.md

@@ -105,7 +105,7 @@ If `namespaced` is set to `true`, please ensure that `sources` my only contains
 | env | list | `[]` | [Environment variables](https://kubernetes.io/docs/tasks/inject-data-application/define-environment-variable-container/) for the `external-dns` container. |
 | excludeDomains | list | `[]` | Intentionally exclude domains from being managed. |
 | extraArgs | object | `{}` | Extra arguments to provide to _ExternalDNS_. An array or map can be used, with maps allowing for value overrides; maps also support slice values to use the same arg multiple times. |
-| extraContainers | object | `{}` | Extra containers to add to the `Deployment`. |
+| extraContainers | list | `[]` | Extra containers to add to the `Deployment`. |
 | extraVolumeMounts | list | `[]` | Extra [volume mounts](https://kubernetes.io/docs/concepts/storage/volumes/) for the `external-dns` container. |
 | extraVolumes | list | `[]` | Extra [volumes](https://kubernetes.io/docs/concepts/storage/volumes/) for the `Pod`. |
 | fullnameOverride | string | `nil` | Override the full name of the chart. |

charts/external-dns/values.schema.json

@@ -81,7 +81,7 @@
     },
     "extraContainers": {
       "description": "Extra containers to add to the `Deployment`.",
-      "type": "object"
+      "type": "array"
     },
     "extraVolumeMounts": {
       "description": "Extra [volume mounts](https://kubernetes.io/docs/concepts/storage/volumes/) for the `external-dns` container.",

charts/external-dns/values.yaml

@@ -60,7 +60,7 @@ rbac:  # @schema additionalProperties: true
 deploymentAnnotations: {}
 
 # -- Extra containers to add to the `Deployment`.
-extraContainers: {}
+extraContainers: []
 
 # -- [Deployment Strategy](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/#strategy).
 deploymentStrategy:  # @schema additionalProperties: true