Move some packages to tmp packages

Dockerfile

@@ -1,26 +1,38 @@
-FROM python:3-slim
+FROM alpine:3.14
 
 # Set working space
 WORKDIR /usr/src/app
 
 # Install dependencies
-RUN apt-get update \
-    # Prevent endless waiting
-    && DEBIAN_FRONTEND=noninteractive \
+RUN apk update --no-cache \
+    # Install packages
+    && apk add --no-cache \
+        tzdata \
+        python3 py3-pip py3-numpy py3-pandas py3-matplotlib \
+        wkhtmltopdf \
     # Set UTC as timezone
     && ln -snf /usr/share/zoneinfo/Europe/Rome /etc/localtime \
-    # Install APT packages
-    && apt-get install -y --fix-missing wkhtmltopdf gfortran \
     # Remove tmp files
-    && apt-get clean && rm -rf /tmp/* /var/tmp/* \
-    # Add PiWheels support
-    && echo "[global]\nextra-index-url=https://www.piwheels.org/simple" >> /etc/pip.conf \
+    && rm -rf /tmp/* /var/tmp/* \
     # Upgrade PIP 
     && python3 -m pip install --no-cache-dir --upgrade pip
 
-# Copy and install requirements
+# Copy PIP extra index URLs
+COPY pip.conf .
+
+# Copy requirements
 COPY requirements.txt .
-RUN python3 -m pip install -r requirements.txt
+
+# Install requirements
+RUN apk update --no-cache \
+    # Install tmp packages 
+    && apk add --no-cache --virtual build-deps gcc python3-dev musl-dev build-base freetype-dev libpng-dev openblas-dev \
+    # Add PIP extra index URLs
+    && mv pip.conf /etc/pip.conf \
+    # Install PIP packages
+    && python3 -m pip install --no-cache-dir -r requirements.txt \
+    # Delete tmp packages
+    && apk del build-deps
 
 # Copy app
 COPY . .

pip.conf

@@ -0,0 +1,5 @@
+[global]
+index-url = https://alpine-wheels.github.io/index
+extra-index-url = https://pypi.python.org/simple
+                  https://pypi.org/simple
+                  https://www.piwheels.org/simple