MSCCL++ Integration (#22734)

Co-authored-by: Caio Rocha <caiorocha@microsof.com>
Co-authored-by: empyreus <rjsouza1995@gmail.com>

docker/Dockerfile

@@ -21,6 +21,7 @@ ARG GITHUB_ARTIFACTORY=github.com
 ARG INSTALL_FLASHINFER_JIT_CACHE=0
 ARG FLASHINFER_VERSION=0.6.12
 ARG MOONCAKE_VERSION=0.3.11.post1
+ARG MSCCLPP_VERSION=sglang-v0.9.1
 #if need other arg please add in MOONCAKE_COMPILE_ARG
 ARG MOONCAKE_COMPILE_ARG="-DUSE_HTTP=ON -DUSE_MNNVL=ON -DUSE_CUDA=ON -DWITH_EP=ON"
 
@@ -443,6 +444,7 @@ ARG USE_LATEST_SGLANG
 ARG GITHUB_ARTIFACTORY
 ARG MOONCAKE_VERSION
 ARG MOONCAKE_COMPILE_ARG
+ARG MSCCLPP_VERSION
 
 WORKDIR /sgl-workspace
 
@@ -523,6 +525,24 @@ RUN --mount=type=cache,target=/root/.cache/pip \
         python3 -m pip install mooncake-transfer-engine==${MOONCAKE_VERSION}; \
     fi
 
+# Install MSCCL++ Python dependencies and package (builds extension via CMake through pip)
+RUN --mount=type=cache,target=/root/.cache/pip \
+    git clone --depth=1 --branch ${MSCCLPP_VERSION} https://${GITHUB_ARTIFACTORY}/microsoft/mscclpp.git /tmp/mscclpp \
+    && case "${CUDA_VERSION}" in \
+           12.*) \
+               CMAKE_ARGS="-DMSCCLPP_BYPASS_GPU_CHECK=ON -DMSCCLPP_USE_CUDA=ON -DMSCCLPP_GPU_ARCHS=80,90,100,100a,103,103a" \
+               python3 -m pip install "/tmp/mscclpp[cuda12]"; \
+               ;; \
+           13.*) \
+               CMAKE_ARGS="-DMSCCLPP_BYPASS_GPU_CHECK=ON -DMSCCLPP_USE_CUDA=ON -DMSCCLPP_GPU_ARCHS=80,90,100,100a,103,103a" \
+               python3 -m pip install "/tmp/mscclpp[cuda13]"; \
+               ;; \
+           *) \
+               echo "Unsupported CUDA version for MSCCL++: ${CUDA_VERSION}" && exit 1; \
+               ;; \
+       esac \
+    && rm -rf /tmp/mscclpp
+
 # Install essential Python packages (use constraints to prevent conflicts)
 RUN --mount=type=cache,target=/root/.cache/pip \
     python3 -m pip install -c /sgl-workspace/constraints.txt \