#!/usr/bin/env bash
# eflag — Envoy/Istio response flag 주석기 (Istio 기본 TEXT 로그 포맷 전용)
# usage: kubectl logs deploy/app -c istio-proxy --tail=200 | eflag
declare -A DESC=(
  [UH]="endpoint 0개 (label 불일치·readiness)"
  [NC]="route가 가리키는 cluster 없음 (DR/host)"
  [NR]="매칭 route 없음 / filter chain 없음"
  [UF]="upstream 연결 수립 실패 (refused·mTLS·NetworkPolicy)"
  [UC]="응답 전 upstream이 연결 종료 (idle timeout 불일치)"
  [UR]="upstream remote reset (RST 수신)"
  [LR]="Envoy가 로컬에서 reset"
  [UO]="circuit breaker overflow (connectionPool 한도)"
  [URX]="retry 한도(HTTP)·connect 시도 한도(TCP) 초과"
  [UT]="upstream 응답 타임아웃 (VS timeout)"
  [DC]="downstream(client)이 먼저 끊음"
  [SI]="stream idle timeout"
  [UMSDR]="max stream duration 도달"
  [DT]="max connection duration 초과"
  [DPE]="downstream HTTP protocol error"
  [UPE]="upstream HTTP protocol error"
  [DF]="DNS 해석 실패"
  [RL]="local rate limit"
  [RLSE]="rate limit service 오류"
  [UAEX]="ext_authz 거부"
  [IH]="잘못된 요청 헤더 (400)"
  [LH]="local health check 실패"
  [OM]="overload manager 차단"
  [NFCF]="filter config warming 미완료"
  [DI]="fault injection delay (의도됨)"
  [FI]="fault injection abort (의도됨)"
)
decode() {
  local f res=""
  IFS=',' read -ra fs <<< "$1"
  for f in "${fs[@]}"; do res+="${f}=${DESC[$f]:-unknown}; "; done
  printf '%s' "${res%; }"
}
while IFS= read -r line; do
  read -ra F <<< "$line"
  printf '%s\n' "$line"
  [[ "${F[5]}" != "-" && -n "${F[5]}" ]] && \
    printf '    \xe2\x86\xb3 [%s] %s | details=%s\n' "${F[4]}" "$(decode "${F[5]}")" "${F[6]}"
done