Baseline modular DNS sync

entrypoint.sh

@@ -0,0 +1,44 @@
+#!/bin/sh
+set -u
+
+INTERVAL_MINUTES="${SYNC_INTERVAL:-1}"
+case "$INTERVAL_MINUTES" in
+    ''|*[!0-9]*)
+        echo "ERROR: SYNC_INTERVAL must be an integer number of minutes" >&2
+        exit 1
+        ;;
+esac
+if [ "$INTERVAL_MINUTES" -lt 1 ]; then
+    echo "ERROR: SYNC_INTERVAL must be at least 1 minute" >&2
+    exit 1
+fi
+
+INTERVAL_SECONDS=$((INTERVAL_MINUTES * 60))
+sleep_pid=""
+
+shutdown() {
+    echo "Stopping DNS sync service..."
+    [ -z "$sleep_pid" ] || kill "$sleep_pid" 2>/dev/null || true
+    exit 0
+}
+trap shutdown INT TERM
+
+echo "DNS sync service started"
+echo "Sync interval: ${INTERVAL_MINUTES} minute(s)"
+echo "Source plugin: ${PROXY:-npm}"
+echo "DNS provider: ${DNS_PROVIDER:-verizon}"
+
+while :; do
+    echo
+    echo "=== DNS sync: $(date -Iseconds) ==="
+    if python -m dns_sync sync; then
+        echo "Sync run completed successfully"
+    else
+        rc=$?
+        echo "ERROR: Sync run failed with exit code ${rc}" >&2
+    fi
+    sleep "$INTERVAL_SECONDS" &
+    sleep_pid=$!
+    wait "$sleep_pid" || true
+    sleep_pid=""
+done