Document scheduled WCX updates

scripts/scheduled_update_wcx.sh

@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+
+#
+# Run the WCX update at most once every 48 hours.
+#
+# The systemd timer invokes this script every night. The timestamp file is
+# updated only after a successful WCX update.
+#
+
+set -Eeuo pipefail
+
+ROOT_DIR="/storage/disk1/WCX"
+
+UPDATE_SCRIPT="${ROOT_DIR}/scripts/update_wcx.sh"
+STAMP_FILE="${ROOT_DIR}/database/last_scheduled_update"
+
+MINIMUM_INTERVAL_SECONDS=$((47 * 60 * 60))
+
+
+log() {
+    printf '[%s] %s\n' \
+        "$(date '+%Y-%m-%d %H:%M:%S')" \
+        "$*"
+}
+
+
+if [[ ! -x "${UPDATE_SCRIPT}" ]]; then
+    log "ERROR: Update script is missing or not executable: ${UPDATE_SCRIPT}" >&2
+    exit 1
+fi
+
+
+if [[ -f "${STAMP_FILE}" ]]; then
+    current_time=$(date +%s)
+    previous_time=$(stat -c %Y "${STAMP_FILE}")
+    elapsed_seconds=$((current_time - previous_time))
+
+    if (( elapsed_seconds < MINIMUM_INTERVAL_SECONDS )); then
+        elapsed_hours=$((elapsed_seconds / 3600))
+
+        log "Skipping update; previous successful scheduled run was ${elapsed_hours} hours ago."
+        exit 0
+    fi
+fi
+
+
+log "Starting scheduled WCX update."
+
+"${UPDATE_SCRIPT}"
+
+touch "${STAMP_FILE}"
+
+log "Scheduled WCX update completed successfully."