move docker image to void linux (#435)

Dockerfile

@@ -1,4 +1,4 @@
-FROM python:3.9-slim
+FROM voidlinux/voidlinux
 
 COPY . /app
 WORKDIR /app
@@ -6,13 +6,12 @@ WORKDIR /app
 ENV PYTHON_BIN python3
 
 RUN \
-    apt-get update && \
-    echo "**** install runtime packages ****" && \
-    apt-get install -y --no-install-recommends \
-        libcairo2 \
-        libjpeg62-turbo \
-        python-lxml \
-        && \
+    echo "**** update packages ****" && \
+    xbps-install -Suy && \
+    echo "**** install system packages ****" && \
+    export runtime_deps='cairo libjpeg-turbo' && \
+    export runtime_pkgs="${runtime_deps} python3-pip python3" && \
+    xbps-install -y $runtime_pkgs && \
     echo "**** install pip packages ****" && \
     pip3 install -U pip setuptools wheel && \
     pip3 install -r requirements.txt && \
@@ -20,6 +19,12 @@ RUN \
     rm -rf \
         /root/.cache \
         /tmp/* \
-        /var/lib/apt/lists/*
+        /var/cache/xbps/*
+
+ARG UID
+ENV UID=${UID:-1000}
+ARG GID
+ENV GID=${GID:-1000}
+USER $UID:$GID
 
 CMD ["/bin/sh", "run.sh", "--pass-errors", "--no-botenv"]