ops: stage rpi reservations without auto restart

services/maintenance/rpi-resource-reservation-daemonset.yaml

@@ -15,7 +15,7 @@ spec:
       labels:
         app: rpi-resource-reservation
       annotations:
-        atlas.bstein.dev/reservation-revision: "2026-05-19-4"
+        atlas.bstein.dev/reservation-revision: "2026-05-19-5"
     spec:
       hostPID: true
       serviceAccountName: node-nofile
@@ -46,6 +46,9 @@ spec:
           image: bitnami/kubectl@sha256:554ab88b1858e8424c55de37ad417b16f2a0e65d1607aa0f3fe3ce9b9f10b131
           command: ["/usr/bin/env", "bash"]
           args: ["/scripts/rpi_resource_reservation.sh"]
+          env:
+            - name: ATLAS_RPI_AUTO_RESTART
+              value: "false"
           resources:
             requests:
               cpu: 10m

services/maintenance/scripts/rpi_resource_reservation.sh

@@ -10,6 +10,7 @@ kubelet_config_dir="${host_root}/var/lib/rancher/k3s/agent/etc/kubelet.conf.d"
 kubelet_config_file="${kubelet_config_dir}/90-atlas-rpi-reservations.conf"
 systemd_override_dir="${host_root}/etc/systemd/system/${unit}.service.d"
 systemd_override_file="${systemd_override_dir}/90-atlas-rpi-reservations.conf"
+auto_restart="${ATLAS_RPI_AUTO_RESTART:-false}"
 
 if [ ! -f "${unit_file}" ]; then
   echo "k3s-agent unit not found; this guardrail only manages worker agents"
@@ -74,7 +75,7 @@ rm -f "${kubelet_tmp_file}"
 
 override_tmp_file="$(mktemp)"
 cat > "${override_tmp_file}" <<'EOF'
-# Managed by Flux via rpi_resource_reservation.sh revision 2026-05-19-4.
+# Managed by Flux via rpi_resource_reservation.sh revision 2026-05-19-5.
 [Service]
 UnsetEnvironment=K3S_KUBELET_ARG
 ExecStart=
@@ -96,11 +97,22 @@ fi
 rm -f "${override_tmp_file}"
 
 if [ "${changed}" -eq 1 ]; then
-  delay="$(( (RANDOM % 420) + 30 ))"
-  echo "updated RPi kubelet reservations; restarting ${unit} after ${delay}s"
-  sleep "${delay}"
+  echo "updated RPi kubelet reservations"
   nsenter --target 1 --mount --uts --ipc --net --pid -- systemctl daemon-reload
-  nsenter --target 1 --mount --uts --ipc --net --pid -- systemctl restart "${unit}"
+
+  if [ "${auto_restart}" = "true" ]; then
+    root_usage="$(df -P "${host_root}" | awk 'NR==2 {gsub(/%/,"",$5); print $5}')" || root_usage=""
+    if [ -n "${root_usage}" ] && [ "${root_usage}" -ge 80 ]; then
+      echo "root filesystem is ${root_usage}% full; leaving ${unit} restart to operator"
+    else
+      delay="$(( (RANDOM % 420) + 30 ))"
+      echo "restarting ${unit} after ${delay}s"
+      sleep "${delay}"
+      nsenter --target 1 --mount --uts --ipc --net --pid -- systemctl restart "${unit}"
+    fi
+  else
+    echo "auto restart disabled; ${unit} will pick up reservations on the next controlled restart"
+  fi
 else
   echo "${config_file} already up to date"
 fi