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

CHANGELOG.md

@@ -4,6 +4,15 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
+## 2026-04-26
+
+### Fixed
+- Setting cron schedule for docker image via environment variable works now
+- Setting time zone for docker image via environment variable works now
+
+### Added
+- Docker image now supports setting PUID and GUID
+
 ## 2025-11-28
 
 ### Fixed

docker/Dockerfile

@@ -2,30 +2,27 @@ FROM alpine:latest
 
 ENV TZ="UTC"
 ENV SCHEDULE="* * * * *"
+ENV PUID=1000
+ENV PGID=1000
 
 ## Configure runtime variables for nsupdate
 ENV NSUPDATE_CONFD_DIR="/config"
 ENV NSUPDATE_LOG_DIR="/log"
 
 ## Install requirements
-RUN apk update
 RUN apk add --no-cache git curl libxml2-utils tzdata jq
 
-# Read timezone from server, so in docker-compose you can change TZ
-RUN ln -sf "/usr/share/zoneinfo/${TZ}" /etc/localtime && \
-    echo "${TZ}" > /etc/timezone && date
-
 # Cache Bust upon new commits
 ADD https://api.github.com/repos/chrisb86/nsupdate/git/refs/heads/main /.git-hashref
 
-COPY nsupdate.sh /usr/local/bin/nsupdate.sh
-RUN chmod +x /usr/local/bin/nsupdate.sh
+COPY --chmod=755 nsupdate.sh /usr/local/bin/nsupdate.sh
+COPY --chmod=755 docker/entrypoint.sh /usr/local/bin/entrypoint.sh
 
-## Setup cron job
-RUN echo "${SCHEDULE} sh /usr/local/bin/nsupdate.sh" >> /etc/crontabs/root
+# Create volume directories (ownership will be set at runtime)
+RUN mkdir -p /config /log
 
 ## Start crond
-CMD [ "crond", "-l", "2", "-f" ]
+ENTRYPOINT [ "/usr/local/bin/entrypoint.sh" ]
 
 VOLUME /config
 VOLUME /log

docker/docker-compose.yml

@@ -1,15 +1,17 @@
-version: '3'
-
 services:
   nsupdate:
-    image: git.debilux.org/chris/nsupdate
+    image: git.debilux.org/chris/nsupdate:latest
     container_name: nsupdate
-    environment:
-      - SCHEDULE="*\2 * * * *"
-      - TZ=Europe/Berlin
-      - NSUPDATE_INWX_USER=YOUR_INWX_USERNAME
-      - NSUPDATE_INWX_PASSWORD=YOUR_INWX_PASSWORD
-    volumes:
-      - ./data:/config
-      - ./log:/log
     restart: unless-stopped
+    environment:
+      - PUID=1000 # (default: 1000)
+      - PGID=1000 # (default: 1000)
+      - VERBOSE=false
+      - DEBUG=false
+      - SCHEDULE=*/2 * * * * (default: * * * * *)
+      - TZ=Europe/Berlin # (default: Etc/UTC)
+      - NSUPDATE_INWX_USER=${NSUPDATE_INWX_USER}
+      - NSUPDATE_INWX_PASSWORD=${NSUPDATE_INWX_PASSWORD}
+    volumes:
+      - ./config:/config
+      - ./log:/log

docker/entrypoint.sh

@@ -1,4 +1,49 @@
 #!/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