Docker: Support for setting cron schedule, PUID, GUID and time zone via env vars.

docker/entrypoint.sh

@@ -1,4 +1,49 @@
-#! /bin/sh
+#!/bin/sh
+set -e
 
-echo "${SCHEDULE} sh nsupdate.sh" >> /etc/crontabs/root
-crond -l 2 -f > /dev/stdout 2> /dev/stderr &
+COMMAND="/usr/local/bin/nsupdate.sh"
+
+# Default schedule if not specified
+SCHEDULE="${SCHEDULE:-* * * * *}"
+
+# Default cron log level if not specified
+CRON_LOG_LEVEL="${CRON_LOG_LEVEL:-2}"
+
+# Default user name not specified
+USERNAME="${USERNAME:-nsupdate}"
+
+# Default UID and GID if not specified
+PUID=${PUID:-1000}
+PGID=${PGID:-1000}
+
+# Default timezone if not specified
+TZ=${TZ:-Etc/UTC}
+
+# Set the timezone
+ln -snf /usr/share/zoneinfo/$TZ /etc/localtime
+echo "$TZ" >/etc/timezone
+echo "Timezone set to $TZ"
+
+# Create group if it doesn't exist yet
+if ! getent group "$USERNAME" > /dev/null 2>&1; then
+  addgroup -g "$PGID" "$USERNAME"
+fi
+
+# Create user if it doesn't exist yet
+if ! getent passwd "$USERNAME" > /dev/null 2>&1; then
+  adduser -u "$PUID" -G "$USERNAME" -D -H -s /bin/false "$USERNAME"
+fi
+
+CRON_FILE="/etc/crontabs/$USERNAME"
+mkdir -p /etc/crontabs
+printf '%s %s\n' "$SCHEDULE" "$COMMAND" > "$CRON_FILE"
+chmod 600 "$CRON_FILE"
+
+# Set correct permissions
+chown -R "$USERNAME":"$USERNAME" /config
+chown -R "$USERNAME":"$USERNAME" /log
+echo "Permissions adjusted"
+
+# Start nsupdate in the foreground with reduced warnings
+echo "Starting cron..."
+exec crond -l "${CRON_LOG_LEVEL}" -f