Dockerfile: refactoring and addition of entrypoint (#12939)

Previously source files were copied first, then build dependencies were
installed, then libraries cloned and built.
This was reordered to be:
1. install dependencies
2. clone and build libraries
3. Pull in minetest source and minetest_game
4. Build minetest

In addition the peristent volumes are now declared.
Also an entrypoint added making it possible to append command line
parameters.

Dockerfile

@@ -1,9 +1,26 @@
-ARG DOCKER_IMAGE=alpine:3.14
+ARG DOCKER_IMAGE=alpine:3.16
 FROM $DOCKER_IMAGE AS builder
 
 ENV MINETEST_GAME_VERSION master
 ENV IRRLICHT_VERSION master
 
+RUN apk add --no-cache git build-base cmake sqlite-dev curl-dev zlib-dev zstd-dev \
+		gmp-dev jsoncpp-dev postgresql-dev ninja luajit-dev ca-certificates
+
+WORKDIR /usr/src/
+RUN git clone --recursive https://github.com/jupp0r/prometheus-cpp/ && \
+	cd prometheus-cpp && \
+	cmake -B build \
+		-DCMAKE_INSTALL_PREFIX=/usr/local \
+		-DCMAKE_BUILD_TYPE=Release \
+		-DENABLE_TESTING=0 \
+		-GNinja && \
+	cmake --build build && \
+	cmake --install build
+
+RUN git clone --depth=1 https://github.com/minetest/irrlicht/ -b ${IRRLICHT_VERSION} && \
+	cp -r irrlicht/include /usr/include/irrlichtmt
+
 COPY .git /usr/src/minetest/.git
 COPY CMakeLists.txt /usr/src/minetest/CMakeLists.txt
 COPY README.md /usr/src/minetest/README.md
@@ -19,28 +36,9 @@ COPY src /usr/src/minetest/src
 COPY textures /usr/src/minetest/textures
 
 WORKDIR /usr/src/minetest
-
+RUN git clone --depth=1 -b ${MINETEST_GAME_VERSION} https://github.com/minetest/minetest_game.git ./games/minetest_game && \
-RUN apk add --no-cache git build-base cmake sqlite-dev curl-dev zlib-dev zstd-dev \
+	rm -fr ./games/minetest_game/.git && \
-		gmp-dev jsoncpp-dev postgresql-dev ninja luajit-dev ca-certificates && \
-	git clone --depth=1 -b ${MINETEST_GAME_VERSION} https://github.com/minetest/minetest_game.git ./games/minetest_game && \
-	rm -fr ./games/minetest_game/.git
-
-WORKDIR /usr/src/
-RUN git clone --recursive https://github.com/jupp0r/prometheus-cpp/ && \
-	cd prometheus-cpp && \
 	cmake -B build \
-		-DCMAKE_INSTALL_PREFIX=/usr/local \
-		-DCMAKE_BUILD_TYPE=Release \
-		-DENABLE_TESTING=0 \
-		-GNinja && \
-	cmake --build build && \
-	cmake --install build
-
-RUN git clone --depth=1 https://github.com/minetest/irrlicht/ -b ${IRRLICHT_VERSION} && \
-	cp -r irrlicht/include /usr/include/irrlichtmt
-
-WORKDIR /usr/src/minetest
-RUN cmake -B build \
 		-DCMAKE_INSTALL_PREFIX=/usr/local \
 		-DCMAKE_BUILD_TYPE=Release \
 		-DBUILD_SERVER=TRUE \
@@ -51,7 +49,7 @@ RUN cmake -B build \
 	cmake --build build && \
 	cmake --install build
 
-ARG DOCKER_IMAGE=alpine:3.14
+ARG DOCKER_IMAGE=alpine:3.16
 FROM $DOCKER_IMAGE AS runtime
 
 RUN apk add --no-cache sqlite-libs curl gmp libstdc++ libgcc libpq luajit jsoncpp zstd-libs && \
@@ -67,5 +65,7 @@ COPY --from=builder /usr/local/share/doc/minetest/minetest.conf.example /etc/min
 USER minetest:minetest
 
 EXPOSE 30000/udp 30000/tcp
+VOLUME /var/lib/minetest/ /etc/minetest/
 
-CMD ["/usr/local/bin/minetestserver", "--config", "/etc/minetest/minetest.conf"]
+ENTRYPOINT ["/usr/local/bin/minetestserver"]
+CMD ["--config", "/etc/minetest/minetest.conf"]