Updates to dockerfile for rootless container

dockerfile

@@ -1,13 +1,21 @@
 FROM python:3.12-slim-bookworm
 
+ARG USER=repeater
+ARG GROUP=repeater
+ARG PUID=15888
+ARG PGID=15888
+
 ENV INSTALL_DIR=/opt/pymc_repeater \
     CONFIG_DIR=/etc/pymc_repeater \
     DATA_DIR=/var/lib/pymc_repeater \
+    HOME_DIR=/home/"$USER" \
     PYTHONUNBUFFERED=1 \
-    SETUPTOOLS_SCM_PRETEND_VERSION_FOR_PYMC_REPEATER=1.0.5
+    SETUPTOOLS_SCM_PRETEND_VERSION_FOR_PYMC_REPEATER=1.0.5 \
+    PUID="$PUID" \
+    PGID="$PGID" 
 
 # Install runtime dependencies only
-RUN apt-get update && apt-get install -y \
+RUN DEBIAN_FRONTEND=noninteractive apt-get update && apt-get install -y \
     libffi-dev \
     python3-rrdtool \
     jq \
@@ -19,8 +27,12 @@ RUN apt-get update && apt-get install -y \
     python3-dev \
     && rm -rf /var/lib/apt/lists/*
 
+# Create the group and user in order to run without root privileges
+RUN groupadd --gid "$PGID" "$GROUP" \
+    && useradd --uid "$PUID" --gid "$PGID" --shell /usr/bin/bash "$USER"
+
 # Create runtime directories
-RUN mkdir -p ${INSTALL_DIR} ${CONFIG_DIR} ${DATA_DIR}
+RUN mkdir -p ${INSTALL_DIR} ${CONFIG_DIR} ${DATA_DIR} ${HOME_DIR}
 
 WORKDIR ${INSTALL_DIR}
 
@@ -29,6 +41,10 @@ COPY repeater ./repeater
 COPY pyproject.toml .
 COPY radio-presets.json .
 COPY radio-settings.json .
+RUN chown -R "$USER":"$GROUP" ${INSTALL_DIR} ${CONFIG_DIR} ${DATA_DIR} ${HOME_DIR}
+
+# Switch to $USER
+USER ${USER}
 
 # Install package
 RUN pip install --no-cache-dir .