fix: Massage the build so the scenarios can run

Fixes #121

sim/Dockerfile

@@ -4,7 +4,7 @@ ARG TARGETARCH
 RUN echo "TARGETARCH : $TARGETARCH"
 
 RUN apt-get update && \
-  DEBIAN_FRONTEND=noninteractive apt-get install -y python3 build-essential cmake wget
+  DEBIAN_FRONTEND=noninteractive apt-get install -y python3 build-essential cmake wget ninja-build
 
 ENV NS_VERS 3.40
 RUN wget -O ns3.tar.bz2 https://www.nsnam.org/release/ns-allinone-$NS_VERS.tar.bz2
@@ -19,7 +19,6 @@ WORKDIR /ns3
 
 RUN mkdir out/
 RUN ./ns3 configure --build-profile=release --out=out/
-RUN ./ns3 build
 
 # make including of the QuicNetworkSimulatorHelper class possible
 COPY CMakeLists.patch .
@@ -29,9 +28,12 @@ RUN rm -r scratch/subdir scratch/scratch-simulator.cc
 COPY scenarios scratch/
 
 # compile all the scenarios
-RUN ./ns3 build  && \
-  cd out/lib && du -sh . && strip -v * && du -sh . && cd ../.. && \
-  cd out/scratch && rm -r subdir ns$NS_VERS-scratch-simulator*
+RUN ./ns3 build
+
+# strip ns3 version prefix from scratches
+RUN find out/scratch -name "ns${NS_VERS}-*" | \
+    sed -e 'p' -E -e "s|ns${NS_VERS}-*||g" | \
+    xargs -n2 mv
 
 ENV PATH="/go/bin:${PATH}"
 COPY wait-for-it-quic /wait-for-it-quic
@@ -44,15 +46,11 @@ RUN apt-get update && \
   apt-get clean
 
 WORKDIR /ns3
-COPY --from=builder /ns3/out/src/fd-net-device/* /ns3/src/fd-net-device/
+COPY --from=builder /ns3/out/src/fd-net-device/* /ns3/out/src/fd-net-device/
 COPY --from=builder /ns3/out/scratch/*/* /ns3/scratch/
-COPY --from=builder /ns3/out/lib/ /ns3/lib
+COPY --from=builder /ns3/out/lib/ /ns3/out/lib
 COPY --from=builder /wait-for-it-quic/wait-for-it-quic /usr/bin
 
-# see https://gitlab.com/nsnam/ns-3-dev/issues/97
-ENV PATH="/ns3/src/fd-net-device/:${PATH}"
-ENV LD_LIBRARY_PATH="/ns3/lib"
-
 COPY run.sh .
 RUN chmod +x run.sh
 RUN mkdir /logs