Run script in conatiner as unrivileged user.

docker/Dockerfile

@@ -2,6 +2,8 @@ FROM alpine:latest
 
 ENV TZ="UTC"
 ENV SCHEDULE="* * * * *"
+ENV PUID=1000
+ENV PGID=1000
 
 ## Configure runtime variables for nsupdate
 ENV NSUPDATE_CONFD_DIR="/config"
@@ -24,6 +26,9 @@ RUN chmod +x /usr/local/bin/nsupdate.sh
 COPY docker/entrypoint.sh /usr/local/bin/entrypoint.sh
 RUN chmod +x /usr/local/bin/entrypoint.sh
 
+# Create volume directories (ownership will be set at runtime)
+RUN mkdir -p /config /log
+
 ## Start crond
 ENTRYPOINT [ "/usr/local/bin/entrypoint.sh" ]
 CMD [ "crond", "-f" ]