Updated dockerfile

Dockerfile

@@ -1,29 +1,43 @@
-FROM docker.snppla.net/snppla/openvpn:1.0
+ARG BASE_IMAGE=docker.snppla.net/snppla/openvpn:1.0
+
+# Build the WebAPI plugin against the same Python 3 the runtime image uses
+FROM ${BASE_IMAGE} AS webapi-build
+
+ARG DEBIAN_FRONTEND=noninteractive
+# Current master; v0.2.1 predates the Deluge 2 fixes
+ARG WEBAPI_REF=114c39324c1297168ffafd0ee9b2b2726c65408c
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+        ca-certificates \
+        git \
+        python3-setuptools && \
+    rm -rf /var/lib/apt/lists/*
+
+RUN git clone https://github.com/idlesign/deluge-webapi.git /src && \
+    git -C /src checkout ${WEBAPI_REF} && \
+    cd /src && \
+    rm -rf dist && \
+    python3 setup.py bdist_egg
+
+FROM ${BASE_IMAGE}
+
+ARG DEBIAN_FRONTEND=noninteractive
 
 EXPOSE 58846
 
 RUN apt-get update && \
-    apt-get install -y \
-        software-properties-common \
-        python3-pip \
-        python3-setuptools \
-        git && \
+    apt-get install -y --no-install-recommends software-properties-common gpg-agent && \
     add-apt-repository ppa:deluge-team/stable -y && \
     apt-get update && \
     apt-get install -y --no-install-recommends deluged && \
+    apt-get purge -y --auto-remove software-properties-common gpg-agent && \
     rm -rf /var/lib/apt/lists/*
 
-# Build and install the WebAPI plugin against the container's Python 3
-RUN git clone https://github.com/idlesign/deluge-webapi.git /tmp/deluge-webapi && \
-    cd /tmp/deluge-webapi && \
-    python3 setup.py bdist_egg && \
-    mkdir -p /config/plugins && \
-    cp dist/WebAPI-*.egg /config/plugins/ && \
-    rm -rf /tmp/deluge-webapi
+COPY --from=webapi-build /src/dist/WebAPI-*.egg /config/plugins/
 
 RUN useradd -ms /bin/bash deluge
 
 COPY deluged_init.sh /sbin/deluged_init.sh
-RUN chmod +x /sbin/deluged_init.sh
 
-CMD ["/sbin/deluged_init.sh"]
+CMD ["/sbin/deluged_init.sh"]