Use alpine:latest

Dockerfile

@@ -1,4 +1,4 @@
-FROM python:3-alpine
+FROM alpine:latest
 
 # Set working space
 WORKDIR /usr/src/app
@@ -7,10 +7,10 @@ WORKDIR /usr/src/app
 RUN apk update \
     # Set UTC as timezone
     && ln -snf /usr/share/zoneinfo/Europe/Rome /etc/localtime \
-    # Install APT packages
+    # Install packages
     && apk add \
-        gcc cmake build-base freetype-dev libpng-dev openblas-dev \
-        py3-numpy py3-pandas py3-matplotlib \
+        build-base freetype-dev libpng-dev openblas-dev \
+        python3 py3-numpy py3-pandas py3-matplotlib \
         wkhtmltopdf \
     # Remove tmp files
     && rm -rf /tmp/* /var/tmp/* \
@@ -19,9 +19,17 @@ RUN apk update \
     # Upgrade PIP 
     && python3 -m pip install --no-cache-dir --upgrade pip
 
-# Copy and install requirements
+# Copy requirements
 COPY requirements.txt .
-RUN python3 -m pip install --no-cache-dir -r requirements.txt
+
+# Install requirements
+RUN apk update \
+    # Install tmp packages 
+    && apk add --virtual build-deps gcc python3-dev musl-dev \
+    # Install PIP packages
+    && python3 -m pip install --no-cache-dir -r requirements.txt \
+    # Delete tmp packages
+    && apk del build-deps
 
 # Copy app
 COPY . .