dig names the resolver it could not reach in its error text, so a DNS timeout was scraped as the answer and restarted DDNS over nothing

2026-08-25 18:29:43 -04:00
parent 172beca3c5
commit 9492dc4c39
1 changed files with 11 additions and 1 deletions
@@ -270,7 +270,17 @@ log "$ICON_SUCCESS Internet reachable"
 # ==============================================================================================
 if [[ -n "$DDNS_DOMAIN" ]] && [[ -n "$DDNS_CONTAINER" ]]; then
    PUBLIC_IP=$(curl -sf --max-time 5 https://ifconfig.me 2>/dev/null | tr -d '[:space:]')
-    DNS_IP=$(dig +short "$DDNS_DOMAIN" @1.1.1.1 2>/dev/null | grep -Eo '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+' | head -1)
+    # dig's failure text names the resolver it could not reach (";; communications error to
    # 1.1.1.1#53: timed out"), so scraping its output for an address yields the server, not the
    # answer — a guaranteed mismatch that restarts DDNS over what is only a DNS timeout. Trust
    # the exit status, and anchor the match so only a bare answer line counts. NXDOMAIN exits 0
    # with no output and correctly falls through to the "could not resolve" branch below.
    if DNS_ANSWER=$(dig +short "$DDNS_DOMAIN" @1.1.1.1 2>/dev/null); then
        DNS_IP=$(printf '%s\n' "$DNS_ANSWER" \
            | grep -Eox '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+' | head -1)
    else
        DNS_IP=""
    fi
    if [[ -z "$PUBLIC_IP" ]]; then
        warn "Could not determine public IP — skipping DDNS check"