add vim

Dockerfile

@@ -11,6 +11,7 @@ RUN \
   apt update && \
   apt install -y cron && \
   apt install -y exim4 && \
+  apt install -y vim.tiny && \
   apt install -y python3 && \
   apt install -y python3-pip && \
   update-alternatives --install /usr/bin/python python /usr/bin/python3 10 && \
@@ -28,11 +29,15 @@ RUN \
   mkdir -p ${APP_DIR} && \
   useradd -d ${APP_DIR} -u 1000 user
 
-VOLUME ${APP_DIR}
 
-COPY crontab /etc/
+COPY crontab ${APP_DIR}/
 COPY *.py ${APP_DIR}/
 
+RUN \
+  ln -s /etc/crontab ${APP_DIR}/crontab 
+
+VOLUME ${APP_DIR}
+
 # USER 1000:1000
 WORKDIR ${APP_DIR}