Backport of [NET-10985] Fix bug where imagePullSecrets were not set up for Gateways into release/1.4.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #4316 to be assessed for backporting due to the inclusion of the label backport/1.4.x.

The below text is copied from the body of the original PR.

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Fixes #4312

Note

In order for the pull secrets to work for a Gateway, they must be available in any namespace that a Gateway is deployed to. This is already the case with injected mesh sidecars if you, for example, consume consul-dataplane from a private image registry, so I have not made any special accomadations for Gateways.

Changes proposed in this PR

Plumb global.imagePullSecrets onto the ServiceAccount created for each Gateway

How I've tested this PR

1. Created a private registry on DockerHub for consul-dataplane, which is used by the gateway's Deployment

   docker pull hashicorp/consul-dataplane:1.5.3
   docker tag hashicorp/consul-dataplane:1.5.3 <your_dockerhub_username>/consul-dataplane:1.5.3
   docker login
   docker push <your_dockerhub_username>/consul-dataplane:1.5.3

2. Created an image pull secret for DockerHub in my K8s cluster

3. Set global.imageConsulDataplane to the private registry version

4. Install using this version of the Helm chart and this build of consul-k8s-control-plane

   values.yaml

   global:
     name: consul
     datacenter: dc1
     imageConsulDataplane: docker.io/<your_dockerhub_username>/consul-dataplane:1.5.3
     imageK8S: consul-k8s-control-plane:local
     imagePullSecrets:
     - name: regcred
     tls:
       enabled: true
       enableAutoEncrypt: true
     acls:
       manageSystemACLs: true
   connectInject:
     enabled: true

   kind create cluster
   make dev-docker && kind load docker-image consul-k8s-control-plane:local
   helm upgrade --install consul /path/to/consul-k8s/charts/consul --namespace consul --create-namespace --values ./values.yaml

How I expect reviewers to test this PR

See above

Checklist

• Tests added
• CHANGELOG entry added

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Overview of commits

• 25ba129 - 34bbb73 - 316985a - aa0758f - b7c1824 - 76415b8 - a6b9305 - 365b2c2 - ac64e83 - e6b636d - 1e3503c - 8260f94 - 16fceb9

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