Refactor dockerfile to reduce build time

Dockerfile

@@ -1,3 +1,43 @@
+FROM debian:buster AS builder
+
+# Build-time dependencies
+RUN apt-get update -yqq && apt-get install -yqq \
+		ca-certificates \
+		build-essential \
+		pkg-config \
+		qt5-default \
+		libqt5svg5* \
+		libboost-dev \
+		libasound2-dev \
+		libssl-dev \
+		libspeechd-dev \
+		libzeroc-ice-dev \
+		libpulse-dev \
+		libcap-dev \
+		libprotobuf-dev \
+		libprotoc-dev \
+		protobuf-compiler \
+		protobuf-compiler-grpc \
+		libgrpc++-dev \
+		libogg-dev \
+		libavahi-compat-libdnssd-dev \
+		libsndfile1-dev \
+		libbz2-dev \
+		libxi-dev \
+		git --no-install-recommends
+
+WORKDIR /usr/src/murmur
+RUN \
+    git clone https://github.com/mumble-voip/mumble.git . \
+	&& git checkout master \
+	&& git submodule init \
+	&& git submodule update
+
+RUN \
+    qmake -recursive main.pro CONFIG+="no-client no-g15 no-bonjour grpc" \
+	&& make release
+
+
 FROM debian:buster
 EXPOSE 64738/tcp 64738/udp
 
@@ -5,71 +45,26 @@ ENV HOME /home/user
 RUN useradd --create-home --home-dir $HOME user \
 	&& chown -R user:user $HOME
 
-# Runtime dependencies for murmurd
-RUN apt-get update && apt-get install -y \
+WORKDIR $HOME
+
+# Runtime dependencies
+RUN apt-get update && apt-get install -yqq \
 		ca-certificates \
-		libprotobuf17 \
+		'libprotobuf[0-9]+$' \
+		libqt5core5a \
+		libqt5dbus5 \
 		libqt5xml5 \
 		libqt5sql5 \
 		libqt5network5 \
 		libcap2 \
-		libgrpc6 \
+		'libgrpc[0-9]+$' \
 		libgrpc++1 \
 		libzeroc-ice3.7 \
-	&& rm -rf /var/lib/apt/lists/*
+	&& apt-get clean && rm -rf /var/lib/apt/lists/*
 
-# The build dependencies will be uninstalled after compilation,
-# so the image doesn't get bloated.
-RUN buildDeps=' \
-		build-essential \
-		pkg-config \
-		qt5-default \
-		qtbase5-dev \
-		qttools5-dev \
-		qttools5-dev-tools \
-		libqt5svg5* \
-		libspeex1 \
-		libspeex-dev \
-		libboost-dev \
-		libasound2-dev \
-		libssl-dev \
-		g++ \
-		libspeechd-dev \
-		libzeroc-ice-dev \
-		zeroc-ice-slice \
-		libpulse-dev \
-		libcap-dev \
-		libspeexdsp-dev \
-		libprotobuf-dev \
-		libprotoc-dev \
-		protobuf-compiler \
-		protobuf-compiler-grpc \
-		libgrpc-dev \
-		libgrpc++-dev \
-		libogg-dev \
-		libavahi-compat-libdnssd-dev \
-		libsndfile1-dev \
-		libxi-dev \
-		git \
-	' \
-	&& set -x \
-	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends \
-	&& rm -rf /var/lib/apt/lists/* \
-	&& mkdir -p /usr/src/murmur \
-	&& git clone https://github.com/mumble-voip/mumble.git /usr/src/murmur \
-	&& cd /usr/src/murmur \
-	&& git checkout 7c67ea33f47716a188da045ead2035f978fc6253 \
-	&& git submodule init \
-	&& git submodule update \
-	&& qmake -recursive main.pro CONFIG+="no-client no-g15 no-bonjour grpc" \
-	&& make \
-	&& cp -r release/ /home/user/release \
-	&& chmod a+r /home/user/release -R \
-	&& rm -rf /usr/src/murmur \
-	&& apt-get purge -y --auto-remove $buildDeps
+COPY --from=builder /usr/src/murmur/release/murmurd /usr/bin/murmurd
 
-WORKDIR $HOME
 USER user
 
-ENTRYPOINT [ "/home/user/release/murmurd" ]
+ENTRYPOINT [ "/usr/bin/murmurd" ]
 CMD [ "-fg", "-v", "-ini", "/data/murmur.ini" ]