tawasuyu/brahman

Sin systemd ni NetworkManager, arje-zero quedaba sin red y sin sshd:
útil como bare init, inútil para sacar logs de una VPS sin pegado en
la consola web. Dos Cards nuevas en el seed prod:

- `net-up`: corre `/usr/sbin/arje-net-up` (script nuevo en scripts/),
  que pone up todas las interfaces y arranca `dhclient -d` en
  foreground sobre la primera no-loopback. Fallback a dhcpcd o
  busybox-udhcpc si dhclient no está. Crea de paso /run/sshd y
  /var/empty/sshd para que sshd no tenga que pelearlos. Restart
  supervisión.

- `sshd`: corre `/usr/sbin/sshd -D -e` (foreground + log a stderr).
  Usa las host keys que Fedora ya tenía. Restart supervisión.

El install script copia arje-net-up.sh a /usr/sbin/arje-net-up.

Prerequisito en el host (no automatizable desde acá): si la VPS no
tiene un cliente DHCP (Fedora Cloud trae sólo NetworkManager por
defecto), el script duerme con el link up y no obtiene IPv4. En ese
caso instalar antes del próximo boot: `dnf install dhcp-client`.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

diff --git a/scripts/arje-net-up.sh b/scripts/arje-net-up.sh
new file mode 100755
index 0000000..1682bee
--- /dev/null
+++ b/scripts/arje-net-up.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+# arje-net-up — sube las interfaces de red y prepara los directorios de
+# runtime que servicios "systemd-aware" (sshd, etc.) esperan que
+# alguien les haya creado. Reemplaza parcialmente lo que
+# systemd-networkd + tmpfiles harían en un boot normal de Fedora.
+#
+# Modelo: DHCP en foreground sobre la primera interfaz no-loopback.
+# arje lo supervisa con Restart, así que si dhclient muere se relanza.
+# IPv6 vía RA lo maneja el kernel solo al subir el link.
+
+set -u
+
+# Directorios que servicios sin systemd necesitan poblados.
+mkdir -p /run/sshd        # PID file de sshd
+mkdir -p /var/empty/sshd  # privsep chroot
+
+# Up todas las interfaces "reales". Se excluyen las virtuales obvias.
+for sysiface in /sys/class/net/*; do
+    [ -d "$sysiface" ] || continue
+    name="$(basename "$sysiface")"
+    case "$name" in
+        lo|sit*|tun*|tap*|veth*|docker*|br-*|cni*|virbr*) continue ;;
+    esac
+    ip link set "$name" up 2>/dev/null || true
+done
+
+# DHCP en foreground sobre la primera interfaz real encontrada.
+iface=""
+for sysiface in /sys/class/net/*; do
+    [ -d "$sysiface" ] || continue
+    name="$(basename "$sysiface")"
+    case "$name" in
+        lo|sit*|tun*|tap*|veth*|docker*|br-*|cni*|virbr*) continue ;;
+    esac
+    iface="$name"
+    break
+done
+
+if [ -z "$iface" ]; then
+    echo "[arje-net-up] no encontré interfaces — durmiendo" >&2
+    exec sleep infinity
+fi
+
+echo "[arje-net-up] interfaz elegida: $iface"
+if command -v dhclient >/dev/null 2>&1; then
+    # `-d` = foreground (sin daemonizar), `-v` = más verbose en stderr.
+    echo "[arje-net-up] dhclient -d -v $iface"
+    exec dhclient -d -v "$iface"
+elif command -v dhcpcd >/dev/null 2>&1; then
+    # `-B` = foreground (no daemonize) en dhcpcd.
+    echo "[arje-net-up] dhcpcd -B $iface"
+    exec dhcpcd -B "$iface"
+elif command -v udhcpc >/dev/null 2>&1; then
+    # busybox udhcpc — `-f` foreground.
+    echo "[arje-net-up] udhcpc -f -i $iface"
+    exec udhcpc -f -i "$iface"
+else
+    echo "[arje-net-up] sin cliente DHCP — mantengo el link up (SLAAC) y duermo" >&2
+    exec sleep infinity
+fi
diff --git a/scripts/install-arje-as-init.sh b/scripts/install-arje-as-init.sh
index a913797..d9b378c 100755
--- a/scripts/install-arje-as-init.sh
+++ b/scripts/install-arje-as-init.sh
@@ -101,6 +101,9 @@ done
 for e in brahman-status busctl brainctl; do
   install -m 0755 "$EX_DIR/$e" "/usr/bin/$e"
 done
+# Helper sh que levanta la red y crea los dirs de runtime que sshd
+# espera. Lo invoca el Card `net-up` del seed.
+install -m 0755 "$SCRIPT_DIR/arje-net-up.sh" /usr/sbin/arje-net-up
 
 echo "[install-arje] paso 3/5: instalar seed en /ente/seed.card.json"
 mkdir -p /ente
diff --git a/seeds/arje-prod.card.json b/seeds/arje-prod.card.json
index 4568459..8d1fd84 100644
--- a/seeds/arje-prod.card.json
+++ b/seeds/arje-prod.card.json
@@ -270,6 +270,38 @@
       "lifecycle": "daemon", "priority": "low",
       "flow": { "input": [], "output": [] }, "genesis": []
     },
+    {
+      "schema_version": 1,
+      "id": "01J8YVKZQ0M0M0M0M0M0M0M0N0",
+      "lineage": null,
+      "label": "net-up",
+      "provides": [], "requires": [],
+      "permissions": { "networking": "full", "filesystem": "read-write", "ipc": { "allow": [] }, "processes": true },
+      "soma": { "namespaces": {"mount":false,"pid":false,"net":false,"uts":false,"ipc":false,"user":false,"cgroup":false},
+                "rlimits": {"mem_bytes":null,"nproc":null,"nofile":null},
+                "cgroup": {"path":"ente.slice/net","cpu_weight":null,"io_weight":null},
+                "cpu_affinity": null },
+      "payload": { "Native": { "exec": "/usr/sbin/arje-net-up", "argv": [], "envp": [["PATH", "/usr/sbin:/usr/bin:/sbin:/bin"]] } },
+      "supervision": { "Restart": { "initial": 500, "max": 30000 } },
+      "lifecycle": "daemon", "priority": "critical",
+      "flow": { "input": [], "output": [] }, "genesis": []
+    },
+    {
+      "schema_version": 1,
+      "id": "01J8YVKZQ0M0M0M0M0M0M0M0S0",
+      "lineage": null,
+      "label": "sshd",
+      "provides": [], "requires": [],
+      "permissions": { "networking": "full", "filesystem": "read-write", "ipc": { "allow": [] }, "processes": true },
+      "soma": { "namespaces": {"mount":false,"pid":false,"net":false,"uts":false,"ipc":false,"user":false,"cgroup":false},
+                "rlimits": {"mem_bytes":null,"nproc":null,"nofile":null},
+                "cgroup": {"path":"ente.slice/sshd","cpu_weight":null,"io_weight":null},
+                "cpu_affinity": null },
+      "payload": { "Native": { "exec": "/usr/sbin/sshd", "argv": ["-D", "-e"], "envp": [["PATH", "/usr/sbin:/usr/bin:/sbin:/bin"]] } },
+      "supervision": { "Restart": { "initial": 1000, "max": 60000 } },
+      "lifecycle": "daemon", "priority": "high",
+      "flow": { "input": [], "output": [] }, "genesis": []
+    },
     {
       "schema_version": 1,
       "id": "01J8YVKZQ0M0M0M0M0M0M0M0G0",