Update Dockerfile

Remove unnecessary dependencies

Dockerfile

@@ -1,11 +1,10 @@
 FROM python:3.8-alpine as base
 
-FROM base as builder
+RUN pip install --no-cache-dir --prefix=/install paho-mqtt
 
-RUN apk add --no-cache --update py3-pip && \
-  pip install --no-cache-dir --prefix=/install paho-mqtt
+FROM python:3.8-alpine
 
-FROM base
+COPY --from=base /install /usr/local
 
 LABEL org.opencontainers.image.source https://github.com/aneisch/thermostat_api_server_docker
 
@@ -14,8 +13,6 @@ HEALTHCHECK --interval=60s --timeout=5s \
 
 EXPOSE 8080
 
-COPY --from=builder /install /usr/local
-
 ENV API_SERVER_ADDRESS 10.0.1.22
 ENV MQTT_SERVER 127.0.0.1
 ENV MQTT_PORT 1883
@@ -27,7 +24,10 @@ COPY ./thermostat_api_server.py /usr/bin/thermostat_api_server.py
 
 RUN apk add --no-cache --update curl && \
   chmod +x /usr/bin/thermostat_api_server.py && \
+  pip cache purge && \ 
+  pip uninstall -y wheel setuptools pip && \ 
   adduser -D thermostat_api && \
+  apk list -I && \
   apk --purge del apk-tools
 
 USER thermostat_api