Improve Dockerfile

docker/Dockerfile

@@ -1,4 +1,6 @@
-FROM python:3.8
+FROM python:3.8.6-alpine3.12
+
+RUN apk add --no-cache git
 
 COPY . /app
 WORKDIR /app/
@@ -7,18 +9,20 @@ COPY ./tosca-templates /opt/tosca-templates
 
 ENV PYTHONPATH=/app
 
-RUN pip3 install gunicorn==20.0.4 && pip install -r /app/requirements.txt
+RUN apk add --no-cache --virtual .build-deps gcc libc-dev git \
+    && pip3 install meinheld==1.0.2 gunicorn==20.0.4 && pip3 install -r /app/requirements.txt \
+    && apk del .build-deps gcc libc-dev git
 
 EXPOSE 5001
 
-ENV WORKER_TYPE sync
+ENV WORKER_TYPE "egg:meinheld#gunicorn_worker"
 ENV TIMEOUT 180
 ENV ENABLE_HTTPS False
 ENV WORKERS 4
 
 COPY ./docker/start.sh /start.sh
 
-CMD ["/bin/bash","/start.sh"]
+CMD ["/bin/sh","/start.sh"]