[BUG] Entrypoint fixing scripts fail on k3s 1.30.3-k3s1 due to missing in-image busybox xargs applet

[zer0def]

Frankly, not sure if that's a here or upstream issue, but worth bringing attention to, nonetheless.

What did you do

• How was the cluster created?
  • k3d cluster create asdf -i docker.io/rancher/k3s:v1.30.3-k3s1 -s 1 -v /tmp/asdf:/var/log

Volume mounted only to collect entrypoint script logs.

What did you expect to happen

Behave nominally and launch the cluster, like with -i docker.io/rancher/k3s:v1.30.2-k3s2.

Screenshots or terminal output

$ k3d cluster create asdf -i docker.io/rancher/k3s:v1.30.3-k3s1 -s 1 -v /tmp/asdf:/var/log
WARN[0000] No node filter specified                     
INFO[0000] Prep: Network                                
INFO[0000] Created network 'k3d-asdf'                   
INFO[0000] Created image volume k3d-asdf-images         
INFO[0000] Starting new tools node...                   
INFO[0000] Starting node 'k3d-asdf-tools'               
INFO[0001] Creating node 'k3d-asdf-server-0'            
INFO[0001] Creating LoadBalancer 'k3d-asdf-serverlb'    
INFO[0001] Using the k3d-tools node to gather environment information 
INFO[0001] HostIP: using network gateway 172.18.0.1 address 
INFO[0001] Starting cluster 'asdf'                      
INFO[0001] Starting servers...                          
INFO[0001] Starting node 'k3d-asdf-server-0'            
ERRO[0002] Failed Cluster Start: Failed to start server k3d-asdf-server-0: Node k3d-asdf-server-0 failed to get ready: error waiting for log line `k3s is up and running` from node 'k3d-asdf-server-0': stopped returning log lines: node k3d-asdf-server-0 is running=true in status=restarting 
ERRO[0002] Failed to create cluster >>> Rolling Back    
INFO[0002] Deleting cluster 'asdf'                      
INFO[0002] Deleting cluster network 'k3d-asdf'          
INFO[0002] Deleting 1 attached volumes...               
FATA[0002] Cluster creation FAILED, all changes have been rolled back!

Entrypoint script output:

$ cat /tmp/asdf/k3d-entrypoints_240801152209.log 
[2024-08-01T15:22:09+00:00] Running k3d entrypoints...
[2024-08-01T15:22:09+00:00] Running /bin/k3d-entrypoint-cgroupv2.sh
[2024-08-01T15:22:09+00:00] [CgroupV2 Fix] Evacuating Root Cgroup ...
xargs: applet not found
sed: write error
[2024-08-01T15:22:09+00:00] Running k3d entrypoints...
[2024-08-01T15:22:09+00:00] Running /bin/k3d-entrypoint-cgroupv2.sh
[2024-08-01T15:22:09+00:00] [CgroupV2 Fix] Evacuating Root Cgroup ...
xargs: applet not found
sed: write error

Which OS & Architecture

$ k3d runtime-info
arch: x86_64
cgroupdriver: systemd
cgroupversion: "2"
endpoint: /var/run/docker.sock
filesystem: extfs
infoname: ayylmao
name: docker
os: Arch Linux
ostype: linux
version: 27.1.1

Which version of k3d

$ k3d version
k3d version v5.7.2
k3s version v1.29.6-k3s2 (default)

Which version of docker

$ docker version
Client:
 Version:           27.1.1
 API version:       1.46
 Go version:        go1.22.5
 Git commit:        63125853e3
 Built:             Thu Jul 25 17:06:22 2024
 OS/Arch:           linux/amd64
 Context:           default

Server:
 Engine:
  Version:          27.1.1
  API version:      1.46 (minimum version 1.24)
  Go version:       go1.22.5
  Git commit:       cc13f95251
  Built:            Thu Jul 25 17:06:22 2024
  OS/Arch:          linux/amd64
  Experimental:     true
 containerd:
  Version:          v1.7.20
  GitCommit:        8fc6bcff51318944179630522a095cc9dbf9f353.m
 crun:
  Version:          1.15
  GitCommit:        e6eacaf4034e84185fd8780ac9262bbf57082278
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0
$ docker info
Client:
 Version:    27.1.1
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  0.16.2
    Path:     /usr/lib/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  2.29.1
    Path:     /usr/lib/docker/cli-plugins/docker-compose

Server:
 Containers: 0
  Running: 0
  Paused: 0
  Stopped: 0
 Images: 84
 Server Version: 27.1.1
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: true
  Native Overlay Diff: false
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2
 Default Runtime: crun
 Init Binary: docker-init
 containerd version: 8fc6bcff51318944179630522a095cc9dbf9f353.m
 runc version: e6eacaf4034e84185fd8780ac9262bbf57082278
 init version: de40ad0
 Security Options:
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 6.10.2-hardened1
 Operating System: Arch Linux
 OSType: linux
 Architecture: x86_64
 CPUs: 16
 Total Memory: 62.11GiB
 Name: ayylmao
 ID: IZXQ:HATC:DIQA:AKQR:6EDN:UYC5:ADGC:WTPS:T7MD:U5YG:7QAG:ODAC
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Username: zer0def
 Experimental: true
 Insecure Registries:
 Live Restore Enabled: false