How to add an image pull secret for xcom sidecar container?

[BjornvandeSandRWS]

How should one add an image pull secret to an xcom sidecar container?

Hello!

We'd like to use a private image for our xcom sidecar containers. Our image repository is password protected.

We try to do so through the following entry in our Helm values file override:

localSettings:
    stringOverride: |
      from airflow.providers.cncf.kubernetes.utils.xcom_sidecar import PodDefaults
      PodDefaults.SIDECAR_CONTAINER.image = "harbor.k8s.services.cnap-am2.intranet.rws.nl/datalabsre/alpine@sha256:56fa17d2a7e7f168a043a2712e63aed1f8543aeafdcee47c58dcffe38ed51099" # 3.21.2

We have a regcred secret in the airflow namespace, but can't find any way to add this image pull secret to our deployment. So we run into auth issues:
#[am2.intranet.rws.nl/datalabsre/alpine@sha256:56fa17d2a7e7f168a043a2712e63aed1f8543aeafdcee47c58dcffe38ed51099](http://harbor.k8s.services.cnap-am2.intranet.rws.nl/datalabsre/alpine@sha256:56fa17d2a7e7f168a043a2712e63aed1f8543aeafdcee47c58dcffe38ed51099)": failed to resolve reference "[harbor.k8s.services.cnap-am2.intranet.rws.nl/datalabsre/alpine@sha256:56fa17d2a7e7f168a043a2712e63aed1f8543aeafdcee47c58dcffe38ed51099](http://harbor.k8s.services.cnap-am2.intranet.rws.nl/datalabsre/alpine@sha256:56fa17d2a7e7f168a043a2712e63aed1f8543aeafdcee47c58dcffe38ed51099)": pull access denied, repository does not exist or may require authorization: authorization failed: no basic auth credentials

The API doesn't seem to offer any entry for an image pull secret:
https://airflow.apache.org/docs/apache-airflow-providers-cncf-kubernetes/stable/_modules/airflow/providers/cncf/kubernetes/utils/xcom_sidecar.html#PodDefaults.SIDECAR_CONTAINER

I see others have had this issue as well:
apache/airflow#10605

Regards,

Bjorn