Persistent Agent — A Kali Workstation on Kubernetes

My laptop is not always online. The Claude mobile app is useful but cannot run terminal commands, install tools, or maintain a persistent workspace. This post covers deploying a persistent Kali Linux container on gpu-1 as an always-on development workstation, accessible via SSH from anywhere on the network.

    flowchart TD
  subgraph GPU1[gpu-1 — i9, 128GB RAM]
    Kali[kali container<br/>kalilinux/kali-rolling]
    SSHD[SSH server<br/>port 2222]
    PVC[50Gi PVC<br/>longhorn-gpu-local<br/>/root]
    Claude[Claude Code<br/>--remote headless]
  end
  subgraph LB[Cilium L2 LoadBalancer]
    SVC[Service<br/>192.168.55.215:22<br/>→ 2222]
  end
  subgraph Client[Operator]
    SSH[ssh root@192.168.55.215]
  end

  SSH --> SVC
  SVC -->|port map 22→2222| SSHD
  SSHD --> Claude
  Claude -->|persists| PVC
  

Why a Container Instead of a VM

A Deployment with a PVCPersistentVolumeClaimA Kubernetes request for durable storage. The pod names a claim and the storage layer — Longhorn on Frank — binds real disk behind it, so the data outlives the pod. is simpler than a full VM:

• Survives restarts — 50Gi PVC at /root preserves home directory, tools, SSH host keys, and Claude Code config across pod restarts.
• Self-heals — pod crashes → Kubernetes restarts it. gpu-1 reboots → pod comes back automatically.
• GitOps model — six YAML files under apps/kali/manifests/, managed by ArgoCD.

A VM would give a full OS with its own kernel, but for a development workstation that mostly runs a terminal, a container is the right tool.

Why Kali

Kali Linux comes with a massive repository of security and networking tools pre-packaged. Even though the primary use case is Claude Code, having nmap, netcat, tcpdump, and hundreds of other tools a single apt-get install away makes it versatile for anything beyond coding.

Architecture

One ArgoCD app, raw manifests:

The Kali container runs on gpu-1 but does not request a GPU resource. It is there for the 128GB RAM and i9 CPU — overkill for a shell but ideal for running Claude Code’s agent loops and large-context operations.

The Startup Script

The container uses the official kalilinux/kali-rolling image with no customisation. A ConfigMap-mounted startup script handles everything:

set -e
apt-get update -qq
apt-get install -y -qq openssh-server curl git procps

# Persist SSH host keys in /root (PVC-backed)
HOST_KEY_DIR=/root/.ssh-host-keys
mkdir -p "$HOST_KEY_DIR"
if [ -f "$HOST_KEY_DIR/ssh_host_ed25519_key" ]; then
  cp "$HOST_KEY_DIR"/ssh_host_* /etc/ssh/
else
  ssh-keygen -A
  cp /etc/ssh/ssh_host_* "$HOST_KEY_DIR/"
fi

cat > /etc/ssh/sshd_config.d/kali-k8s.conf <<'SSHCONF'
PermitRootLogin prohibit-password
PubkeyAuthentication yes
PasswordAuthentication no
SSHCONF

cp /etc/ssh-keys/authorized_keys /root/.ssh/authorized_keys
/usr/sbin/sshd
exec sleep infinity

Two worth noting:

1. Host key persistence — host keys stored on PVC. Without it, every restart regenerates keys and SSH warns about changed fingerprints.
2. No custom image — apt-get install runs on every start (~30s). For a workstation that restarts once a month, building a custom image is not worth the overhead.

SSH Key as a Public Resource

The authorized_keys file contains a public key — it is not sensitive. Instead of SOPSSecrets OPerationSMozilla's tool for encrypting the *values* in a YAML file while leaving the keys readable, so an encrypted secret still reviews as a sensible diff. encryption, the key lives directly in apps/kali/manifests/secret.yaml and is managed by ArgoCD like any other resource.

The Always-On Agent

After deployment:

ssh root@192.168.55.215
# Install Claude Code
claude --remote          # headless session, survives SSH disconnect

Claude Code’s --remote flag starts a headless session that persists independently of the SSH connection. Start a task from your laptop, close the lid, check results from your phone later. The agent keeps running because the container keeps running.

Missteps

Recovery Path

References

• Kalilinux/kali-rolling — Official Kali Docker image
• Claude Code CLI — Headless remote mode

Next: Progressive Delivery with Argo Rollouts