From ca5fbceac3ca211d1d20dd9d434792fa37813efa Mon Sep 17 00:00:00 2001
From: Christian Busch <chris@debilux.org>
Date: Sun, 26 Apr 2026 16:35:17 +0200
Subject: [PATCH] Updated docker File

---
 docker/Dockerfile    |  9 +++++----
 docker/entrypoint.sh | 22 +++++++++++++++++++---
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/docker/Dockerfile b/docker/Dockerfile
index 86c1306..83cb595 100755
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -21,11 +21,12 @@ ADD https://api.github.com/repos/chrisb86/nsupdate/git/refs/heads/main /.git-has
 COPY nsupdate.sh /usr/local/bin/nsupdate.sh
 RUN chmod +x /usr/local/bin/nsupdate.sh
 
-## Setup cron job
-RUN echo "${SCHEDULE} sh /usr/local/bin/nsupdate.sh" >> /etc/crontabs/root
+COPY docker/entrypoint.sh /usr/local/bin/entrypoint.sh
+RUN chmod +x /usr/local/bin/entrypoint.sh
 
 ## Start crond
-CMD [ "crond", "-l", "2", "-f" ]
+ENTRYPOINT [ "/usr/local/bin/entrypoint.sh" ]
+CMD [ "crond", "-f" ]
 
 VOLUME /config
-VOLUME /log
+VOLUME /log
\ No newline at end of file
diff --git a/docker/entrypoint.sh b/docker/entrypoint.sh
index c079839..66d0be5 100644
--- a/docker/entrypoint.sh
+++ b/docker/entrypoint.sh
@@ -1,4 +1,20 @@
-#! /bin/sh
+#!/bin/sh
 
-echo "${SCHEDULE} sh nsupdate.sh" >> /etc/crontabs/root
-crond -l 2 -f > /dev/stdout 2> /dev/stderr &
\ No newline at end of file
+set -eu
+
+SCHEDULE="${SCHEDULE:-* * * * *}"
+CRON_LOG_LEVEL="${CRON_LOG_LEVEL:-2}"
+CRON_FILE="/etc/crontabs/root"
+
+printf '%s /usr/local/bin/nsupdate.sh\n' "${SCHEDULE}" > "${CRON_FILE}"
+
+if [ "$#" -gt 0 ]; then
+	if [ "$1" = "crond" ]; then
+		shift
+		exec crond -l "${CRON_LOG_LEVEL}" "$@"
+	fi
+
+	exec "$@"
+fi
+
+exec crond -l "${CRON_LOG_LEVEL}" -f
\ No newline at end of file