containerd.registryMirrors sets deprecated config.toml

[yuzhouliu9]

/kind bug

On a kops managed node with containerd.registryMirrors set, run the following:

# ctr deprecations list
ID                                                LAST OCCURRENCE                   MESSAGE
io.containerd.deprecation/cri-registry-mirrors    2026-04-18T06:47:40.658258357Z    The `mirrors` property of `[plugins."io.containerd.grpc.v1.cri".registry]` is deprecated since containerd v1.5 and will be removed in containerd v2.1. Use `config_path` instead.

This is because kops spec containerd.registryMirrors configures /etc/containerd/config.toml with the deprecated config

    [plugins."io.containerd.grpc.v1.cri".registry]

      [plugins."io.containerd.grpc.v1.cri".registry.mirrors]

        [plugins."io.containerd.grpc.v1.cri".registry.mirrors."docker.io"]
          endpoint = ["https://registry-mirror-..."]

Set here

containerd deprecation notice

Note that containerd has deferred the removal of this field to 2.3.

I have not tested it yet, but configuring registryMirrors should still work on kops 1.34.

---

1. What kops version are you running? The command kops version, will display
this information.

1.33.2

2. What Kubernetes version are you running? kubectl version will print the
version if a cluster is running or provide the Kubernetes version specified as
a kops flag.

v1.33.10

3. What cloud provider are you using?
AWS

4. What commands did you run? What is the simplest way to reproduce this issue?
N/A

5. What happened after the commands executed?
N/A

6. What did you expect to happen?
N/A

7. Please provide your cluster manifest. Execute
kops get --name my.example.com -o yaml to display your cluster manifest.
You may want to remove your cluster name and other sensitive information.

Only relevant portion of spec provided

  containerd:
    registryMirrors:
      docker.io:
      - https://registry-mirror-dockerhub.example.com

8. Please run the commands with most verbose logging by adding the -v 10 flag.
Paste the logs into this report, or in a gist and provide the gist link here.
N/A

9. Anything else do we need to know?
N/A