feat: SAC fallback failure counter (2.3)

After SAC_FALLBACK_FAILURES consecutive POST errors, skip SAC until
/health recovers; persist count in SAC_FAIL_COUNT_FILE.

sac-client.sh

@@ -70,6 +70,59 @@ sac_spool_remove() {
  rm -f "${dir}/${event_id}.json"
 }
 
+sac_fail_count_file() {
+ printf '%s' "${SAC_FAIL_COUNT_FILE:-/var/lib/ssh-monitor/sac-fail.count}"
+}
+
+sac_read_fail_count() {
+ local f
+ f="$(sac_fail_count_file)"
+ if [ -f "$f" ]; then
+ cat "$f" 2>/dev/null | tr -dc '0-9'
+ else
+ printf '0'
+ fi
+}
+
+sac_write_fail_count() {
+ local n="$1"
+ local f
+ f="$(sac_fail_count_file)"
+ mkdir -p "$(dirname "$f")" 2>/dev/null || true
+ printf '%s' "$n" >"$f"
+}
+
+sac_reset_fail_count() {
+ sac_write_fail_count 0
+}
+
+sac_increment_fail_count() {
+ local n max
+ max="${SAC_FALLBACK_FAILURES:-5}"
+ n="$(sac_read_fail_count)"
+ n=$((n + 1))
+ sac_write_fail_count "$n"
+ [ "$n" -ge "$max" ]
+}
+
+# В fallback: после N подряд ошибок POST не дергать SAC, пока /health снова не OK.
+sac_should_attempt_send() {
+ local mode
+ mode="$(sac_normalize_mode "${UseSAC:-off}")"
+ [ "$mode" = "fallback" ] || return 0
+ local max n
+ max="${SAC_FALLBACK_FAILURES:-5}"
+ n="$(sac_read_fail_count)"
+ [ "$n" -lt "$max" ] && return 0
+ if sac_check_health; then
+ sac_reset_fail_count
+ write_log "SAC: /health восстановлен, снова отправляем в SAC (fallback)"
+ return 0
+ fi
+ write_log "WARN: SAC fallback: пропуск POST ($n>=$max сбоев подряд), только локальные каналы"
+ return 1
+}
+
 # POST готового JSON (ingest / повтор из spool). Возврат 0 при HTTP 202.
 sac_post_payload() {
  local payload="$1"
@@ -83,6 +136,10 @@ sac_post_payload() {
  return 0
  fi
 
+ if ! sac_should_attempt_send; then
+ return 1
+ fi
+
  event_id="$(printf '%s' "$payload" | python3 -c 'import json,sys; print(json.load(sys.stdin)["event_id"])')" || return 1
  event_type="$(printf '%s' "$payload" | python3 -c 'import json,sys; print(json.load(sys.stdin).get("type","?"))')" || event_type="?"
 
@@ -101,12 +158,14 @@ sac_post_payload() {
 
  if [ "$http_code" = "202" ]; then
  sac_spool_remove "$event_id" 2>/dev/null || true
+ sac_reset_fail_count
  write_log "SAC: принято event_id=$event_id type=$event_type"
  return 0
  fi
 
  write_log "WARN: SAC POST HTTP $http_code: $(tr '\n' ' ' <"$resp" | head -c 200)"
  sac_spool_write "$event_id" "$payload"
+ sac_increment_fail_count || write_log "WARN: SAC fallback: достигнут порог SAC_FALLBACK_FAILURES"
  return 1
 }
 
@@ -156,6 +215,10 @@ sac_send_event() {
  return 0
  fi
 
+ if ! sac_should_attempt_send; then
+ return 1
+ fi
+
  local payload http_code event_id
  payload="$(SAC_EVENT_TYPE="$event_type" \
   SAC_SEVERITY="$severity" \

ssh-monitor.conf.example

@@ -32,6 +32,8 @@ UseSAC="off"
 SAC_URL="https://sac.kalinamall.ru"
 SAC_API_KEY=""
 SAC_SPOOL_DIR="/var/lib/ssh-monitor/sac-spool"
+SAC_FAIL_COUNT_FILE="/var/lib/ssh-monitor/sac-fail.count"
+SAC_FALLBACK_FAILURES="5"
 SAC_TIMEOUT_SEC="12"
 
 # SMTP (python3). Для авто-режима почты нужны MAIL_SMTP_HOST, MAIL_FROM, MAIL_TO.