Abandon switch to slim since it has more complications with ARM build…

… variants. We may need to split this into a multi-stage build to reduce the final image size (350MB uncompressed) and build times (current 38m on GitHub)

Dockerfile

@@ -1,21 +1,21 @@
 # Fully qualified container name prevents public registry typosquatting
-FROM docker.io/library/python:3-slim
+FROM docker.io/library/python:3-alpine
 
 ARG UID=1012
 ARG GID=1012
 
-RUN addgroup --system --gid $GID vuegraf
-RUN adduser  --system --gid $GID --uid $UID --home /opt/vuegraf vuegraf
+RUN addgroup -S -g $GID vuegraf
+RUN adduser  -S -g $GID -u $UID -h /opt/vuegraf vuegraf
 
 WORKDIR /opt/vuegraf
 
 # Install pip dependencies with minimal container layer size growth
 COPY src/requirements.txt ./
 RUN set -x && \
-    apt update -y && \
-    apt upgrade -y && \
+    apk add --no-cache build-base libffi-dev rust cargo openssl-dev && \
     pip install --upgrade pip && \
     pip install --no-cache-dir -r requirements.txt && \
+    apk del build-base libffi-dev rust cargo openssl-dev && \
     rm -rf /var/cache/apk /opt/vuegraf/requirements.txt
 
 # Copying code in after requirements are built optimizes rebuild