Bring script headers onto the template and close safeguard gaps

Headers claimed protections the code never had, and several destructive paths had no
guard against a collapsed config value.

Docker_Essentials/docker_daily_restart.sh

@@ -14,6 +14,33 @@
 # so there is no second list to maintain.
 #
 # ==============================================================================================
+# OPERATIONAL MODEL
+# ==============================================================================================
+#
+# Containers are processed one at a time in dependency-safe order:
+#
+#   1. Build restart order
+#        → build_restart_order() sorts DAILY_RESTART_CONTAINERS by WATCHDOG_DEPENDENCIES
+#
+#   2. Skip anything docker_update.sh already rebuilt this run
+#        → a rebuild onto a new image already restarted it moments ago
+#
+#   3. Inspect container state
+#        missing  → skip, not an error
+#        stopped  → skip, stopped state is respected
+#        running  → restart
+#
+#   4. Restart with retry
+#        → retry_docker wraps each attempt in a timeout, up to RETRY_COUNT
+#
+#   5. Verify it stayed running
+#        → verify_running() settles for RESTART_VERIFY_WAIT then checks State.Running
+#        → a container that crashes immediately is marked failed and notified
+#
+#   6. Prune dangling images
+#        → restarts swap onto new images, leaving the old ones dangling
+#
+# ==============================================================================================
 # DESIGN PRINCIPLES
 # ==============================================================================================
 #
@@ -37,6 +64,27 @@
 # OPERATIONAL SAFEGUARDS
 # ==============================================================================================
 #
+# Root Enforcement
+#   Docker operations require root privileges.
+#
+# Docker Presence Check
+#   Verifies the docker binary exists before execution. Notifies on absence —
+#   a missing binary during the maintenance window is worth knowing about.
+#
+# Docker Daemon Check
+#   Verifies the daemon is responsive before any restart work. Every container
+#   would otherwise fail its inspect and be logged as an unknown-status failure,
+#   burying one daemon fault under a list of bogus per-container errors.
+#
+# Host Detection
+#   detect_hosts() identifies which server is running the script and aliases
+#   HOST*_DAILY_RESTART_CONTAINERS and HOST*_WATCHDOG_DEPENDENCIES to the
+#   correct host's values.
+#
+# Empty List Guard
+#   Exits cleanly with a pointer to the relevant conf key if
+#   DAILY_RESTART_CONTAINERS is unconfigured for this host.
+#
 # Dependency Ordering
 #   Containers restart in dependency-safe order using HOST*_WATCHDOG_DEPENDENCIES.
 #   CONTAINER_DELAY seconds between dependency restart and dependent restart gives
@@ -53,6 +101,11 @@
 #   cannot cause this script to hang indefinitely. Timed-out commands retry
 #   per RETRY_COUNT before marking as failed.
 #
+# Stale Rebuild-List Guard
+#   The rebuilt-container list written by docker_update.sh is discarded if older
+#   than DOCKER_UPDATE_REBUILT_STALE_HOURS. A stale file would otherwise suppress
+#   real restarts based on an update run that never happened today.
+#
 # Lock Acquisition
 #   acquire_lock() prevents concurrent execution if a previous run is still active.
 #
@@ -134,6 +187,14 @@ fi
 # detect_hosts() sets MY_ID and aliases HOST*_DAILY_RESTART_CONTAINERS → DAILY_RESTART_CONTAINERS
 detect_hosts
 
+# Without this, a hung daemon fails every container's inspect individually and the summary
+# reports a list of unknown-status failures instead of the one fault that caused them.
+if ! timeout "$DOCKER_TIMEOUT" docker info >/dev/null 2>&1; then
+    error "Docker daemon not responding — skipping daily restart"
+    notify "Daily restart skipped on $(hostname) — Docker daemon not responding" "Docker Daily Restart" "warning"
+    exit 1
+fi
+
 if [[ ${#DAILY_RESTART_CONTAINERS[@]} -eq 0 ]]; then
     warn "DAILY_RESTART_CONTAINERS is empty for $MY_ID — nothing to restart"
     warn "Check HOST${MY_ID#HOST}_DAILY_RESTART_CONTAINERS in host*.conf"
@@ -213,7 +274,7 @@ LAST_RESTARTED=""
 for container in "${ORDERED_RESTART[@]}"; do
     [[ -z "$container" ]] && continue
     c_start=$(date +%s)
-    c_image=$(docker inspect --format '{{.Config.Image}}' "$container" 2>/dev/null || echo "unknown")
+    c_image=$(timeout "$DOCKER_TIMEOUT" docker inspect --format '{{.Config.Image}}' "$container" 2>/dev/null || echo "unknown")
     log "━━━ $ICON_CONTAINERS $container ($c_image) ━━━"
 
     if ! timeout "$DOCKER_TIMEOUT" docker inspect "$container" &>/dev/null; then
@@ -242,7 +303,6 @@ for container in "${ORDERED_RESTART[@]}"; do
                 RESTARTED+=("$container")
             else
                 if retry_docker docker restart "$container"; then
-                    [[ "${RESTART_VERIFY_WAIT:-3}" -gt 0 ]] && sleep "${RESTART_VERIFY_WAIT:-3}"
                     if verify_running "$container"; then
                         echo "$ICON_STARTED $container restarted and running in $(format_duration $(( $(date +%s) - c_start ))) ✅"
                         RESTARTED+=("$container")
@@ -283,7 +343,7 @@ if [[ "$DRY_RUN" == true ]]; then
     warn "DRY RUN — would prune dangling images"
     PRUNED_SUMMARY="(dry run)"
 else
-    PRUNED_OUTPUT=$(docker image prune -f 2>&1)
+    PRUNED_OUTPUT=$(timeout "$DOCKER_TIMEOUT" docker image prune -f 2>&1)
     [[ "$ENABLE_LOGGING" == "true" ]] && echo "$PRUNED_OUTPUT" | sed 's/^/  /'
     PRUNED_SUMMARY=$(echo "$PRUNED_OUTPUT" | grep -E "^Total reclaimed" || echo "nothing reclaimed")
 fi