build mysql dependencies in Dockerfile

Dockerfile

@@ -4,13 +4,19 @@ EXPOSE 8042
 WORKDIR /usr/src/app
 
 RUN apk add --no-cache \
-    python3 \
-    py3-gunicorn
+        python3 \
+        py3-gunicorn
 
 COPY requirements.txt .
 RUN pip3 install --upgrade pip && \
     pip3 install --no-cache-dir -r requirements.txt
 
+# For production: build mysql dependencies
+RUN apk add --virtual build-deps gcc python3-dev musl-dev && \
+    apk add --no-cache mariadb-dev && \
+    pip3 install --no-cache-dir mysqlclient && \
+    apk del build-deps
+
 COPY . .
 
 # TODO #1: build a real production setup with gunicorn, nginx for static files etc.