steps:

# OS from VMSS is very clean... Need to install basic utilities.

# Build essentials are required.

- script: |
    set -e
    sudo apt update
    sudo apt install -y build-essential cmake
  displayName: Install build essential


# Install azcopy for cache download.
# https://docs.microsoft.com/en-us/azure/storage/common/storage-use-azcopy-v10#use-azcopy-in-a-script

- script: |
    set -e
    mkdir -p tmp
    cd tmp
    wget -O azcopy_v10.tar.gz https://aka.ms/downloadazcopy-v10-linux && tar -xf azcopy_v10.tar.gz --strip-components=1
    sudo cp ./azcopy /usr/bin/
    sudo chmod +x /usr/bin/azcopy
  displayName: Setup azcopy

# VM with GPU needs to install drivers. Reference:
# https://docs.microsoft.com/en-us/azure/virtual-machines/linux/n-series-driver-setup
# https://docs.nvidia.com/cuda/cuda-installation-guide-linux/index.html
# https://linuxhint.com/install-cuda-ubuntu/

- script: |
    lspci | grep -i NVIDIA
  displayName: GPU status verification

- script: |
    set -e
    sudo apt install linux-headers-$(uname -r) -y
    sudo wget -O /etc/apt/preferences.d/cuda-repository-pin-600 https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/cuda-ubuntu2004.pin
    sudo apt-key adv --fetch-keys https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/3bf863cc.pub
    sudo add-apt-repository "deb https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/ /"
    sudo apt update
    sudo apt install -y cuda-drivers
  displayName: Install CUDA

# Technically we need a reboot here, but looks like it also works without reboot.

- script: |
    nvidia-smi
  displayName: nvidia-smi verification


# UsePythonVersion task only works when the specific Python version is already installed.

# The following is for linux.
# Reference: https://dev.to/akaszynski/create-an-azure-self-hosted-agent-without-going-insane-173g
# We only need Python 3.7 and 3.9 for now.
# --system-site-packages is required to make packages installed with --user visible to virtualenv.
- script: |
    set -e
    sudo add-apt-repository ppa:deadsnakes/ppa
    sudo apt install -y python3.7-dev python3.7-venv python3.9-dev python3.9-venv
    mkdir $(Agent.ToolsDirectory)/Python
  displayName: Download Python

- script: |
    set -e
    cd $(Agent.ToolsDirectory)/Python
    PY37_VER=$(python3.7 -c "import sys; print('.'.join([f'{val}' for val in sys.version_info[:3]]))")
    mkdir $PY37_VER
    ln -s $PY37_VER 3.7
    cd $PY37_VER
    python3.7 -m venv x64 --system-site-packages
    touch x64.complete
  displayName: Configure Python 3.7

- script: |
    set -e
    cd $(Agent.ToolsDirectory)/Python
    PY39_VER=$(python3.9 -c "import sys; print('.'.join([f'{val}' for val in sys.version_info[:3]]))")
    mkdir $PY39_VER
    ln -s $PY39_VER 3.9
    cd $PY39_VER
    python3.9 -m venv x64 --system-site-packages
    touch x64.complete
  displayName: Configure Python 3.9