Support containerd config_path for stargz snapshotter

[brandond]

• This should have been done as part of https://github.com/k3s-io/k3s/pull/8973 but I didn't realize stargz already supported it.
• Ref: https://github.com/containerd/stargz-snapshotter/pull/331

[mdrahman-suse]

Validated on master (v1.30) branch with commit df5db28a

Environment and Config

Ubuntu 22.04, Single server

• config.yaml

  write-kubeconfig-mode: 644
  cluster-init: true
  node-name: server1
  snapshotter: stargz

  Testing:

• Add config.yaml on /etc/rancher/k3s/
• Install k3s
• Ensure cluster is up and running
• Check presence of [plugins."io.containerd.snapshotter.v1.stargz".registry] and config_path under [plugins."io.containerd.snapshotter.v1.stargz".registry] in config.toml

Replication:

$ k3s -v
k3s version v1.30.1+k3s1 (80978b5b)
go version go1.22.2

• config_path and [plugins."io.containerd.snapshotter.v1.stargz".registry] in config.toml

  
  $ sudo cat /var/lib/rancher/k3s/agent/etc/containerd/config.toml
  # File generated by k3s. DO NOT EDIT. Use config.toml.tmpl instead.
  version = 2

[plugins."io.containerd.internal.v1.opt"] path = "/var/lib/rancher/k3s/agent/containerd" [plugins."io.containerd.grpc.v1.cri"] stream_server_address = "127.0.0.1" stream_server_port = "10010" enable_selinux = false enable_unprivileged_ports = true enable_unprivileged_icmp = true sandbox_image = "rancher/mirrored-pause:3.6"

[plugins."io.containerd.grpc.v1.cri".containerd] snapshotter = "stargz" disable_snapshot_annotations = false

[plugins."io.containerd.snapshotter.v1.stargz"] cri_keychain_image_service_path = "/run/containerd-stargz-grpc/containerd-stargz-grpc.sock" [plugins."io.containerd.snapshotter.v1.stargz".cri_keychain] enable_keychain = true ...

## Validation:

$ k3s -v k3s version v1.30.1+k3s-df5db28a (df5db28a) go version go1.22.2

- `config_path` is present under `[plugins."io.containerd.snapshotter.v1.stargz".registry]` in config.toml

$ sudo cat /var/lib/rancher/k3s/agent/etc/containerd/config.toml

File generated by k3s. DO NOT EDIT. Use config.toml.tmpl instead.

version = 2

[plugins."io.containerd.internal.v1.opt"] path = "/var/lib/rancher/k3s/agent/containerd" [plugins."io.containerd.grpc.v1.cri"] stream_server_address = "127.0.0.1" stream_server_port = "10010" enable_selinux = false enable_unprivileged_ports = true enable_unprivileged_icmp = true sandbox_image = "rancher/mirrored-pause:3.6"

[plugins."io.containerd.grpc.v1.cri".containerd] snapshotter = "stargz" disable_snapshot_annotations = false

[plugins."io.containerd.snapshotter.v1.stargz"] cri_keychain_image_service_path = "/run/containerd-stargz-grpc/containerd-stargz-grpc.sock" [plugins."io.containerd.snapshotter.v1.stargz".cri_keychain] enable_keychain = true

[plugins."io.containerd.snapshotter.v1.stargz".registry] config_path = "/var/lib/rancher/k3s/agent/etc/containerd/certs.d" ...