switch to multi-stage build, prepare multi-arch build

contrib/docker/Dockerfile.template

@@ -0,0 +1,45 @@
+%QEMU_FROM_LINE%
+FROM %BASE_IMAGE% as build
+%QEMU_FROM_COPY%
+RUN apt-get update && apt-get install -y \
+    libmosquitto-dev libstdc++6 libc6 libgcc1 \
+    curl \
+    autoconf automake g++ make git \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /build
+
+ENV EBUSD_VERSION %EBUSD_VERSION%
+ENV EBUSD_ARCH %EBUSD_ARCH%
+
+RUN git clone https://github.com/john30/ebusd.git /build \
+    && %EBUSD_MAKE%
+
+ARG UPLOAD_URL
+ARG UPLOAD_CREDENTIALS
+%EBUSD_UPLOAD_LINE%
+
+
+FROM %BASE_IMAGE%-slim
+%QEMU_FROM_COPY%
+RUN apt-get update && apt-get install -y \
+    logrotate libmosquitto1 libstdc++6 libc6 libgcc1 \
+    && rm -rf /var/lib/apt/lists/*
+
+LABEL maintainer "ebusd@ebusd.eu"
+
+ENV EBUSD_VERSION %EBUSD_VERSION%
+ENV EBUSD_ARCH %EBUSD_ARCH%
+
+LABEL version "${EBUSD_VERSION}-${EBUSD_ARCH}%EBUSD_VERSION_VARIANT%"
+
+COPY --from=build /build/ebusd-*_mqtt1.deb ebusd.deb
+
+RUN dpkg -i ebusd.deb \
+    && rm -f ebusd.deb%EXTRA_RM%
+
+EXPOSE 8888
+
+COPY docker-entrypoint.sh /
+ENTRYPOINT ["/docker-entrypoint.sh"]
+CMD ["-f", "--scanconfig"]