Convert C++ Example to Docker Build Pattern

While this does make it a longer build time, it makes it easier to get
started with the C++ example because there is no tooling dependencies
other than Docker (Make is even optional, it just sets the default
arguments up).

Also provides an end to end example of compiling the SDK, installing it
and then using it with another C++ project.

Co-authored-by: Dmitry Sazonov <dsazonoff@gmail.com>

.dockerignore

@@ -14,6 +14,9 @@
 
 # project specific
 .*
+/build
+/cmd
+/sdks/cpp/.build
 .idea
 *.zip
 /release

examples/cpp-simple/CMakeLists.txt

@@ -47,4 +47,7 @@ target_link_libraries(${PROJECT_NAME} PUBLIC agones)
 
 if (MSVS)
   target_compile_options(${PROJECT_NAME} PUBLIC /wd4101 /wd4146 /wd4251 /wd4661)
-endif()
+endif()
+
+# Installation
+install(TARGETS ${PROJECT_NAME} EXPORT ${PROJECT_NAME} RUNTIME DESTINATION .)

examples/cpp-simple/Dockerfile

@@ -12,12 +12,34 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+FROM gcc:8 as builder
+
+WORKDIR /project
+
+ADD https://cmake.org/files/v3.14/cmake-3.14.1-Linux-x86_64.sh /cmake-3.14.1-Linux-x86_64.sh
+RUN mkdir /opt/cmake
+RUN sh /cmake-3.14.1-Linux-x86_64.sh --prefix=/opt/cmake --skip-license
+RUN ln -s /opt/cmake/bin/cmake /usr/local/bin/cmake
+RUN cmake --version
+
+COPY ./sdks/cpp sdk
+RUN cd sdk && mkdir -p .build && \
+    cd .build && \
+    cmake .. -DCMAKE_BUILD_TYPE=Release -G "Unix Makefiles" -Wno-dev && \
+    cmake --build . --target install
+
+COPY ./examples/cpp-simple cpp-simple
+RUN cd cpp-simple && mkdir -p .build && \
+    cd .build && \
+    cmake .. -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=.bin && \
+    cmake --build . --target install
+
 FROM debian:stretch
 RUN useradd -m server
 
-COPY ./bin/server-static /home/server/server-static
+COPY --from=builder /project/cpp-simple/.build/.bin/cpp-simple /home/server/cpp-simple
 RUN chown -R server /home/server && \
-    chmod o+x /home/server/server-static
+    chmod o+x /home/server/cpp-simple
 
 USER server
-ENTRYPOINT /home/server/server-static
+ENTRYPOINT /home/server/cpp-simple

examples/cpp-simple/Makefile

@@ -23,16 +23,13 @@
 #     \_/ \__,_|_|  |_|\__,_|_.__/|_|\___|___/
 #
 
-CXX = g++
-CPPFLAGS += -I/usr/local/include -pthread
-CXXFLAGS += -std=c++11
-LDFLAGS += -L/usr/local/lib -lagonessdk -lgrpc++_unsecure -lgrpc -lprotobuf -lpthread -ldl
 REPOSITORY = gcr.io/agones-images
 
 # Directory that this Makefile is in.
 mkfile_path := $(abspath $(lastword $(MAKEFILE_LIST)))
 project_path := $(dir $(mkfile_path))
-server_tag = $(REPOSITORY)/cpp-simple-server:0.4
+server_tag = $(REPOSITORY)/cpp-simple-server:0.5
+root_path = $(realpath $(project_path)/../..)
 
 #   _____                    _
 #  |_   _|_ _ _ __ __ _  ___| |_ ___
@@ -41,25 +38,6 @@ server_tag = $(REPOSITORY)/cpp-simple-server:0.4
 #    |_|\__,_|_|  \__, |\___|\__|___/
 #                 |___/
 
-# build the library
-build: ensure-bin server-dynamic server-static
-
-# Build a docker image for the server, and tag it
-build-image:
-	docker build $(project_path) --tag=$(server_tag)
-
-# make the server executable
-server-dynamic: server.o
-	$(CXX) $^ $(LDFLAGS) -o $(project_path)bin/$@
-
-# make the server executable
-server-static: server.o
-	$(CXX) $^ $(LDFLAGS) -o $(project_path)bin/$@ -static
-
-# make sure the bin directory exists
-ensure-bin:
-	-mkdir $(project_path)/bin
-
-clean:
-	-rm -r $(project_path)/bin
-	-rm *.o
+# build the cpp-simple binary
+build:
+	cd $(root_path) && docker build -f $(project_path)/Dockerfile --tag=$(server_tag) .