Harden Pushover error notifications on abort

scripts/agathe_backup.sh

@@ -18,6 +18,7 @@ set -Eeuo pipefail
 WG_IF="wg0"
 VPN_TEST_IP="10.202.101.10"
 WG_WAS_STARTED_BY_SCRIPT=0
+PUSHOVER_FAILURE_SENT=0
 
 LOCK_FILE="/var/lock/agathe_backup.lock"
 
@@ -89,16 +90,27 @@ send_pushover() {
   local priority="${2:-0}"
 
   if command -v curl >/dev/null 2>&1; then
-    curl -s \
+    local rc
+    set +e
+    curl -fsS --max-time 20 --retry 2 --retry-delay 2 \
       --form-string "token=${PUSHOVER_API_TOKEN}" \
       --form-string "user=${PUSHOVER_USER_TOKEN}" \
       --form-string "title=${PUSHOVER_TITLE}" \
       --form-string "message=${message}" \
       --form-string "priority=${priority}" \
-      https://api.pushover.net/1/messages.json >/dev/null || true
+      https://api.pushover.net/1/messages.json >/dev/null
+    rc=$?
+    set -e
+    if [[ "$rc" -ne 0 ]]; then
+      log "WARNUNG: Pushover konnte nicht gesendet werden (curl Exit-Code: $rc)."
+      return 1
+    fi
   else
     log "WARNUNG: curl fehlt, Pushover konnte nicht gesendet werden."
+    return 1
   fi
+
+  return 0
 }
 
 need_root() {
@@ -148,13 +160,22 @@ on_error() {
   local exit_code=$?
   local line_no="${1:-unknown}"
   log "FEHLER in Zeile ${line_no}, Exit-Code ${exit_code}"
-  send_pushover "Backup FEHLER auf $(hostname): Zeile ${line_no}, Exit-Code ${exit_code}" 1
+  if send_pushover "Backup FEHLER auf $(hostname): Zeile ${line_no}, Exit-Code ${exit_code}" 1; then
+    PUSHOVER_FAILURE_SENT=1
+  fi
   trap - EXIT
   cleanup
   exit "$exit_code"
 }
 
 on_exit() {
+  local exit_code=$?
+  if [[ "$exit_code" -ne 0 && "$PUSHOVER_FAILURE_SENT" -eq 0 ]]; then
+    log "WARNUNG: Abbruch ohne ERR-Notification erkannt (Exit-Code ${exit_code}), sende Fallback-Pushover."
+    if send_pushover "Backup FEHLER auf $(hostname): Exit-Code ${exit_code} (EXIT trap)." 1; then
+      PUSHOVER_FAILURE_SENT=1
+    fi
+  fi
   cleanup
 }