The agent host's vault and SilverBullet (M5.4)

deploy/agent-host sets up the vault on nisse-host (infra/tofu#77) and
SilverBullet over it: the operator writes the vault, the agents' memory/
is read-only to it, and only the operator's Caddy reaches it, which
serves vault.dongar.net to the LAN. scripts/agent-host.sh installs and
checks it from here.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

scripts/agent-host.sh

@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+# The agent host's vault and SilverBullet (deploy/agent-host), from this box.
+#   scripts/agent-host.sh install   copy deploy/agent-host over and run setup.sh
+#   scripts/agent-host.sh check     check SilverBullet runs and the mounts and
+#                                   firewall hold
+#   scripts/agent-host.sh ssh ...   run a command on the host
+# Trusts only the host keys bot-ansible posted (~/bin/tofu-wait.sh saved them).
+set -euo pipefail
+
+host=${AGENT_HOST:-nisse-host.garrett-hall.com}
+key=${AGENT_HOST_KEY:-/root/nisse-e2e/ssh/id_ed25519}
+known=${AGENT_HOST_KNOWN:-/root/nisse-e2e/nisse-host.known_hosts}
+repo=$(cd "$(dirname "$0")/.." && pwd)
+
+on_host() {
+  ssh -i "$key" -o UserKnownHostsFile="$known" -o StrictHostKeyChecking=yes \
+    -o BatchMode=yes -o ConnectTimeout=10 "ubuntu@$host" "$@"
+}
+
+case ${1:-} in
+  install)
+    tar -C "$repo/deploy" -cf - agent-host |
+      on_host 'rm -rf /tmp/agent-host && tar -C /tmp -xf - && sudo bash /tmp/agent-host/setup.sh'
+    ;;
+  check)
+    on_host 'bash -s' <<'EOF'
+set -u
+fail=0
+ok() { echo "ok:   $1"; }
+bad() { echo "FAIL: $1"; fail=1; }
+cd /opt/stacks/silverbullet
+[ "$(sudo docker compose ps --status running -q | wc -l)" -ge 1 ] \
+  && ok "SilverBullet is running" || bad "SilverBullet isn't running"
+code=$(curl -s -o /dev/null -w '%{http_code}' http://127.0.0.1:3000/)
+case $code in 2??|3??) ok "it answers locally ($code)" ;; *) bad "it answers $code" ;; esac
+probe=.nisse-probe-$$
+sudo docker compose exec -T -u 1000 silverbullet sh -c "touch /vault/infrastructure/$probe && rm /vault/infrastructure/$probe" \
+  && ok "the operator's folders are writable" || bad "the operator's folders aren't writable"
+if sudo docker compose exec -T silverbullet sh -c "touch /vault/memory/$probe" 2>/dev/null; then
+  sudo docker compose exec -T silverbullet rm -f "/vault/memory/$probe"
+  bad "memory/ is writable from SilverBullet, even as root in it"
+else
+  ok "memory/ is read-only to SilverBullet"
+fi
+sudo iptables -S DOCKER-USER | grep -q -- '--comment nisse-firewall' \
+  && ok "the firewall rule is in place" || bad "no firewall rule"
+exit $fail
+EOF
+    ;;
+  ssh)
+    shift
+    on_host "$@"
+    ;;
+  *)
+    sed -n '2,7p' "$0"
+    exit 2
+    ;;
+esac