add entrypoint script and update dockerfile

Dockerfile

@@ -1,12 +1,11 @@
-FROM 3.11.1-alpine3.17
+FROM python:3.11.1-alpine3.17
 
-RUN adduser -D app && apk update && apk add fetchmail
+RUN adduser -D app && apk update && apk add fetchmail runuser
 
-USER app
-WORKDIR /app
+COPY ./requirements.txt /home/app/requirements.txt
+COPY ./pmml.py /home/app/pmml.py
+COPY ./entrypoint.sh /home/app/entrypoint.sh
 
-COPY ./requirements.txt ./requirements.txt
+RUN pip install -r /home/app/requirements.txt 
 
-RUN pip install -r requirements.txt
-
-ENTRYPOINT ["fetchmail"]
+ENTRYPOINT ["/home/app/entrypoint.sh"]

entrypoint.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+DOCKER_USER=app
+DOCKER_HOME=/home/app
+
+chown app $DOCKER_HOME/.fetchmailrc
+chown app $DOCKER_HOME/pmml.py
+chown app $DOCKER_HOME/.pmmlrc
+exec runuser -u $DOCKER_USER -- fetchmail -d 60 -N