Feat: PUID/PGID support via env variables in Dockerfile

Dockerfile

@@ -1,22 +1,47 @@
-FROM python:3.11-slim
-WORKDIR /app
+ARG PYTHON_VERSION=3.11
+FROM python:${PYTHON_VERSION}-slim
 
 LABEL "author"="swing music"
+LABEL "description"="Swing Music is a beautiful, self-hosted music player for your local audio files. Like a cooler Spotify ... but bring your own music."
+
+# Default user and group IDs
+ENV PUID=1000 \
+    PGID=1000 \
+    USER_NAME=swingmusic
+
 EXPOSE 1970/tcp
 VOLUME /music
 VOLUME /config
 
-RUN apt-get update 
+# Prevents Python from writing pyc files.
+ENV PYTHONDONTWRITEBYTECODE=1
+# Keeps Python from buffering stdout and stderr to avoid situations where
+# the application crashes without emitting any logs due to buffering.
+ENV PYTHONUNBUFFERED=1
 
-RUN apt-get install -y gcc libev-dev 
-RUN apt-get install -y ffmpeg libavcodec-extra 
-RUN apt-get clean && rm -rf /var/lib/apt/lists/*
+ENV DEBIAN_FRONTEND=noninteractive
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends \
+        gcc \
+        libev-dev \
+        libc6-dev \
+        ffmpeg \
+        libavcodec-extra \
+        gosu \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
 
-# Copy repo root files needed for installation
-COPY pyproject.toml requirements.txt version.txt ./ 
+WORKDIR /app
+
+RUN groupadd -g ${PGID} ${USER_NAME} \
+    && useradd -u ${PUID} -g ${PGID} -m ${USER_NAME}
+
+COPY pyproject.toml requirements.txt version.txt README.md* ./
 COPY src/ ./src/
 
-# Install the package and its dependencies
-RUN pip install --no-cache-dir .
+RUN --mount=type=cache,target=/root/.cache/pip \
+    python -m pip install .
+
+COPY entrypoint.sh /entrypoint.sh
 
-ENTRYPOINT ["python", "-m", "swingmusic", "--host", "0.0.0.0", "--config", "/config"]
+ENTRYPOINT ["/entrypoint.sh", "python", "-m", "swingmusic", "--host", "0.0.0.0", "--config", "/config"]

README.md

@@ -124,6 +124,9 @@ services:
     restart: unless-stopped
 ```
 
+> [!TIP]
+> You can set user permissions by adding the `PUID` and `PGID` environment variables to the compose file. Default values are `PUID=1000` and `PGID=1000`.
+
 ### Contributing and Development
 
 Swing Music is looking for contributors. If you're interested, please join us at the [Swing Music Community](https://t.me/+9n61PFcgKhozZDE0) group on Telegram. For more information, take a look at https://github.com/swing-opensource/swingmusic/issues/186.

entrypoint.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+set -e
+
+if [ "$(id -u)" = "0" ]; then
+    CURRENT_UID=$(id -u ${USER_NAME})
+    CURRENT_GID=$(id -g ${USER_NAME})
+
+    if [ -n "${PGID:-}" ]; then
+        case "$PGID" in
+            *[!0-9]*)
+                echo "Invalid PGID '$PGID': must be a non-empty numeric value." >&2
+                exit 1
+                ;;
+        esac
+        if [ "$PGID" != "$CURRENT_GID" ]; then
+            groupmod -g "$PGID" ${USER_NAME}
+        fi
+    fi
+
+    if [ -n "${PUID:-}" ]; then
+        case "$PUID" in
+            *[!0-9]*)
+                echo "Invalid PUID '$PUID': must be a non-empty numeric value." >&2
+                exit 1
+                ;;
+        esac
+        if [ "$PUID" != "$CURRENT_UID" ]; then
+            usermod -u "$PUID" ${USER_NAME}
+        fi
+    fi
+
+    if ! chown -R ${USER_NAME}:${USER_NAME} /app /config 2>/dev/null; then
+        echo "Warning: failed to chown /app and /config for user '${USER_NAME}'. This may indicate permission issues or read-only volumes." >&2
+    fi
+
+    exec gosu ${USER_NAME} "$@"
+fi
+
+exec "$@"