# whisper.cpp built for NVIDIA Blackwell (compute capability 12.0 / sm_120).
#
# Why this exists: the official `ghcr.io/ggml-org/whisper.cpp:main-cuda` image
# only ships CUDA kernels for sm_75/80/86/90 (Turing -> Hopper) and includes
# no PTX, so it fails to initialize CUDA on RTX 50-series Blackwell GPUs with
# `ggml_cuda_init: failed to initialize CUDA: system has unsupported display
# driver / cuda driver combination`.
#
# Build:
#   docker build -t whisper.cpp:cuda-blackwell ./whisper-cuda-blackwell
#
# Override args if needed:
#   --build-arg CUDA_ARCH=120        # set to your GPU's compute capability
#   --build-arg WHISPER_REF=v1.7.6   # pin to a specific whisper.cpp tag

ARG CUDA_VERSION=12.9.1
ARG UBUNTU_VERSION=24.04

# ---------- Build stage ----------
FROM nvidia/cuda:${CUDA_VERSION}-devel-ubuntu${UBUNTU_VERSION} AS builder

ARG CUDA_ARCH=120
ARG WHISPER_REF=master

RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
        build-essential \
        cmake \
        git \
        ca-certificates \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /src
RUN git clone --depth 1 --branch "${WHISPER_REF}" https://github.com/ggml-org/whisper.cpp.git . 2>/dev/null \
 || git clone --depth 1 https://github.com/ggml-org/whisper.cpp.git .

# Build with CUDA enabled and explicit Blackwell architecture.
# Adding "${CUDA_ARCH}-virtual" emits PTX too so JIT can target newer chips
# from the same family if Blackwell ever gets minor variants.
#
# Why the linker dance:
# `libggml-cuda.so` calls into the CUDA driver API (`cuGetErrorString`,
# `cuMemMap`, etc.) but doesn't declare a `DT_NEEDED` for libcuda. When the
# whisper-server executable links against libggml-cuda.so, ld then sees those
# unresolved symbols and refuses. We fix it two ways at once:
#   1. Symlink the driver stub to /usr/local/cuda/lib64/stubs/libcuda.so.1
#      and register the dir with ldconfig so `-lcuda` resolves.
#   2. Force `-lcuda` onto the link line via CMAKE_*_LINKER_FLAGS, with
#      `--no-as-needed` so ld keeps it even when ordering would normally drop it.
RUN ln -sf /usr/local/cuda/lib64/stubs/libcuda.so /usr/local/cuda/lib64/stubs/libcuda.so.1 \
 && echo "/usr/local/cuda/lib64/stubs" > /etc/ld.so.conf.d/cuda-stubs.conf \
 && ldconfig \
 && cmake -B build \
        -DGGML_CUDA=ON \
        -DCMAKE_CUDA_ARCHITECTURES="${CUDA_ARCH};${CUDA_ARCH}-virtual" \
        -DCMAKE_BUILD_TYPE=Release \
        -DCMAKE_EXE_LINKER_FLAGS="-L/usr/local/cuda/lib64/stubs -Wl,--no-as-needed -lcuda -Wl,--as-needed" \
        -DCMAKE_SHARED_LINKER_FLAGS="-L/usr/local/cuda/lib64/stubs -Wl,--no-as-needed -lcuda -Wl,--as-needed" \
 && cmake --build build --config Release -j "$(nproc)" \
        --target whisper-server whisper-cli whisper-bench

# ---------- Runtime stage ----------
FROM nvidia/cuda:${CUDA_VERSION}-cudnn-runtime-ubuntu${UBUNTU_VERSION}

RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
        ffmpeg \
        curl \
        ca-certificates \
        libgomp1 \
    && rm -rf /var/lib/apt/lists/*

# Binaries
COPY --from=builder /src/build/bin/whisper-server /usr/local/bin/whisper-server
COPY --from=builder /src/build/bin/whisper-cli    /usr/local/bin/whisper-cli
COPY --from=builder /src/build/bin/whisper-bench  /usr/local/bin/whisper-bench

# whisper.cpp builds dynamic libs by default; copy them all.
COPY --from=builder /src/build/src/libwhisper.so*                       /usr/local/lib/
COPY --from=builder /src/build/ggml/src/libggml.so*                     /usr/local/lib/
COPY --from=builder /src/build/ggml/src/libggml-base.so*                /usr/local/lib/
COPY --from=builder /src/build/ggml/src/libggml-cpu.so*                 /usr/local/lib/
COPY --from=builder /src/build/ggml/src/ggml-cuda/libggml-cuda.so*      /usr/local/lib/

# Helpful extras: the model-download script and the JFK sample.
COPY --from=builder /src/models/download-ggml-model.sh /app/models/download-ggml-model.sh
COPY --from=builder /src/samples /app/samples

RUN ldconfig

WORKDIR /app
EXPOSE 8080
ENTRYPOINT ["whisper-server"]