Standarize image by using shared / similair layers

core/admin/Dockerfile

@@ -1,12 +1,16 @@
-FROM python:3-alpine
-
+FROM alpine:3.8
+# python3 shared with most images
+RUN apk add --no-cache \
+    python3 py3-pip \
+  && pip3 install --upgrade pip
+# Image specific layers under this line
 RUN mkdir -p /app
 WORKDIR /app
 
 COPY requirements-prod.txt requirements.txt
 RUN apk add --no-cache openssl curl \
- && apk add --no-cache --virtual build-dep openssl-dev libffi-dev python-dev build-base \
- && pip install -r requirements.txt \
+ && apk add --no-cache --virtual build-dep openssl-dev libffi-dev python3-dev build-base \
+ && pip3 install -r requirements.txt \
  && apk del --no-cache build-dep
 
 COPY mailu ./mailu

core/admin/start.py

@@ -1,7 +1,7 @@
-#!/usr/local/bin/python3
+#!/usr/bin/python3
 
 import os
 
-os.system("python manage.py advertise")
-os.system("python manage.py db upgrade")
-os.system("gunicorn -w 4 -b :80 --access-logfile - --error-logfile - --preload mailu:app")
+os.system("python3 manage.py advertise")
+os.system("python3 manage.py db upgrade")
+os.system("gunicorn -w 4 -b :80 --access-logfile - --error-logfile - --preload mailu:app")

core/dovecot/Dockerfile

@@ -1,10 +1,16 @@
 FROM alpine:3.8
-
+# python3 shared with most images
 RUN apk add --no-cache \
-     dovecot dovecot-pigeonhole-plugin dovecot-fts-lucene rspamd-client \
-     bash python3 py3-pip \
- && pip3 install --upgrade pip \
- && pip3 install jinja2 podop tenacity
+    python3 py3-pip \
+  && pip3 install --upgrade pip
+# Shared layer between rspamd, postfix, dovecot, unbound and nginx
+RUN pip3 install jinja2
+# Shared layer between rspamd, postfix, dovecot
+RUN pip3 install tenacity
+# Image specific layers under this line
+RUN apk add --no-cache \
+  dovecot dovecot-pigeonhole-plugin dovecot-fts-lucene rspamd-client bash \
+  && pip3 install podop
 
 COPY conf /conf
 COPY start.py /start.py

core/nginx/Dockerfile

@@ -1,9 +1,13 @@
 FROM alpine:3.8
-
+# python3 shared with most images
+RUN apk add --no-cache \
+    python3 py3-pip \
+  && pip3 install --upgrade pip
+# Shared layer between rspamd, postfix, dovecot, unbound and nginx
+RUN pip3 install jinja2
+# Image specific layers under this line
 RUN apk add --no-cache certbot nginx nginx-mod-mail openssl curl \
- python py-jinja2 py-requests-toolbelt py-pip \
- && pip install --upgrade pip \
- && pip install idna
+ && pip3 install idna requests
 
 COPY conf /conf
 COPY *.py /

core/nginx/config.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 import jinja2
 import os

core/nginx/letsencrypt.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 import os
 import time

core/nginx/start.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 import os
 import subprocess

core/postfix/Dockerfile

@@ -1,9 +1,16 @@
 FROM alpine:3.8
+# python3 shared with most images
+RUN apk add --no-cache \
+    python3 py3-pip \
+  && pip3 install --upgrade pip
+# Shared layer between rspamd, postfix, dovecot, unbound and nginx
+RUN pip3 install jinja2
+# Shared layer between rspamd, postfix, dovecot
+RUN pip3 install tenacity
+# Image specific layers under this line
 
 RUN apk add --no-cache postfix postfix-pcre rsyslog \
-    python3 py3-pip \
- && pip3 install --upgrade pip \
- && pip3 install jinja2 podop tenacity
+ && pip3 install podop
 
 COPY conf /conf
 COPY start.py /start.py