Arm64 support for Azure Functions Host

[paldaniel]

I have tried to run Azure Functions (host: 4.3.2, python 3.9) as an Azure IoT Edge module on Raspberry PI 4 (arm64) and had some success. I wanna share my steps to have official support for arm64 architecture.
Python image

1. Change runtime-image architecture

FROM mcr.microsoft.com/dotnet/sdk:6.0.100-bullseye-slim-arm64v8 AS runtime-image

2. Rebuild host to arm64, remove workers (could not build them to work on arm64 correctly)

RUN BUILD_NUMBER=$(echo ${HOST_VERSION} | cut -d'.' -f 3) && \
    git clone --branch v${HOST_VERSION} https://github.com/Azure/azure-functions-host /src/azure-functions-host && \
    cd /src/azure-functions-host && \
    HOST_COMMIT=$(git rev-list -1 HEAD) && \
    dotnet publish -v q /p:BuildNumber=$BUILD_NUMBER /p:CommitHash=$HOST_COMMIT src/WebJobs.Script.WebHost/WebJobs.Script.WebHost.csproj -c Release --output /azure-functions-host --runtime linux-arm64 --self-contained && \
    rm -rf /root/.local /root/.nuget /src /azure-functions-host/workers

3. Rebuild extension bundles
   This worked only with full rebuild on my pc (amd64) to arm64
   For both 2.12.1, 3.9.1

dotnet add package Microsoft.Azure.WebJobs
dotnet build --output ./bin_v3/linux-arm64 --runtime linux-arm64

4. Change python to arm64

FROM arm64v8/python:3.9.12-slim-bullseye

5. Remove MSSQL support (could not build it to arm64)

RUN apt-get update && \
    apt-get install -y wget && \
    echo 'debconf debconf/frontend select Noninteractive' | debconf-set-selections && \
    apt-get update && \
    apt-get install -y apt-transport-https curl gnupg && \
    # MSSQL dependencies
    # curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - && \
    # curl https://packages.microsoft.com/config/debian/11/prod.list > /etc/apt/sources.list.d/mssql-release.list && \
    # # Needed for libss1.0.0 and in turn MS SQL
    # echo 'deb http://security.debian.org/debian-security jessie/updates main' >> /etc/apt/sources.list && \
    # # install necessary locales for MS SQL
    # apt-get update && apt-get install -y locales && \
    # echo 'en_US.UTF-8 UTF-8' > /etc/locale.gen && \
    # locale-gen && \
    # # install MS SQL related packages
    # apt-get update && \
    # apt-get install -y unixodbc msodbcsql18 mssql-tools && \
    # .NET Core dependencies
    apt-get install -y --no-install-recommends ca-certificates \
    libc6 libgcc1 libgssapi-krb5-2 libicu67 libssl1.1 libstdc++6 zlib1g && \
    rm -rf /var/lib/apt/lists/* && \
    # Custom dependencies:
    #  OpenCV dependencies:
    apt-get update && \
    apt-get install -y libglib2.0-0 libsm6 libxext6 libxrender-dev && \
    #  binutils
    apt-get install -y binutils && \
    #  OpenMP dependencies
    apt-get install -y libgomp1 && \
    # mysql dependencies
    apt-get install -y default-libmysqlclient-dev

6. Rebuild Azure Functions Python Worker and add required files:

COPY --from=runtime-image ["/azure-functions-host", "/azure-functions-host"]
COPY --from=runtime-image ["/FuncExtensionBundles", "/FuncExtensionBundles" ]

RUN mkdir -p /azure-functions-host/workers/python/3.9/LINUX/Arm64 &&\
    apt install -y git &&\
    pip install grpcio-tools &&\
    pip install git+https://github.com/Azure/azure-functions-python-worker#egg=azure-functions-worker --target=/azure-functions-host/workers/python/3.9/LINUX/Arm64 &&\
    apt purge git -y &&\
    pip uninstall -y grpcio-tools

COPY ["worker.py", "/azure-functions-host/workers/python/3.9/LINUX/Arm64"]
COPY ["worker.config.json", "/azure-functions-host/workers/python" ]
COPY ["start.sh", "/azure-functions-host" ]
COPY ["sshd_config", "/etc/ssh/"]

worker.py:

import os
import sys

from pathlib import Path

# User packages
PKGS_PATH = "site/wwwroot/.python_packages"
VENV_PKGS_PATH = "site/wwwroot/worker_venv"

PKGS = "lib/site-packages"

# Azure environment variables
AZURE_WEBSITE_INSTANCE_ID = "WEBSITE_INSTANCE_ID"
AZURE_CONTAINER_NAME = "CONTAINER_NAME"
AZURE_WEBJOBS_SCRIPT_ROOT = "AzureWebJobsScriptRoot"


def is_azure_environment():
    """Check if the function app is running on the cloud"""
    return (AZURE_CONTAINER_NAME in os.environ
            or AZURE_WEBSITE_INSTANCE_ID in os.environ)


def add_script_root_to_sys_path():
    """Append function project root to module finding sys.path"""
    functions_script_root = os.getenv(AZURE_WEBJOBS_SCRIPT_ROOT)
    if functions_script_root is not None:
        sys.path.append(functions_script_root)


def determine_user_pkg_paths():
    """This finds the user packages when function apps are running on the cloud

    For Python 3.7+, we only accept:
        /home/site/wwwroot/.python_packages/lib/site-packages
    """
    minor_version = sys.version_info[1]

    home = Path.home()
    pkgs_path = os.path.join(home, PKGS_PATH)
    usr_packages_path = []

    if minor_version in (7, 8, 9, 10):
        usr_packages_path.append(os.path.join(pkgs_path, PKGS))
    else:
        raise RuntimeError(f'Unsupported Python version: 3.{minor_version}')

    return usr_packages_path


if __name__ == '__main__':
    # worker.py lives in the same directory as azure_functions_worker
    func_worker_dir = str(Path(__file__).absolute().parent)
    env = os.environ

    if is_azure_environment():
        user_pkg_paths = determine_user_pkg_paths()
        joined_pkg_paths = os.pathsep.join(user_pkg_paths)

        # On cloud, we prioritize third-party user packages
        # over worker packages in PYTHONPATH
        env['PYTHONPATH'] = f'{joined_pkg_paths}:{func_worker_dir}'
        os.execve(sys.executable,
                  [sys.executable, '-m', 'azure_functions_worker']
                  + sys.argv[1:],
                  env)
    else:
        # On local development, we prioritize worker packages over
        # third-party user packages (in .venv)
        sys.path.insert(1, func_worker_dir)
        add_script_root_to_sys_path()
        from azure_functions_worker import main

        main.main()

worker.config.json

{
    "description":{
        "language":"python",
        "defaultRuntimeVersion":"3.9",
        "supportedOperatingSystems":["LINUX", "OSX", "WINDOWS"],
        "supportedRuntimeVersions":["3.7", "3.8", "3.9", "3.10"],
        "supportedArchitectures":["X64", "X86", "Arm64"],
        "extensions":[".py"],
        "defaultExecutablePath":"python",
        "defaultWorkerPath":"%FUNCTIONS_WORKER_RUNTIME_VERSION%/{os}/{architecture}/worker.py"
    }
}

7. Based on requirements I have used the start.sh entrypoint

ENTRYPOINT ["/azure-functions-host/start.sh"]

The full Dockerfile:

ARG HOST_VERSION=4.3.2

FROM mcr.microsoft.com/dotnet/sdk:6.0.100-bullseye-slim-arm64v8 AS runtime-image
ARG HOST_VERSION


ENV PublishWithAspNetCoreTargetManifest=false

RUN BUILD_NUMBER=$(echo ${HOST_VERSION} | cut -d'.' -f 3) && \
    git clone --branch v${HOST_VERSION} https://github.com/Azure/azure-functions-host /src/azure-functions-host && \
    cd /src/azure-functions-host && \
    HOST_COMMIT=$(git rev-list -1 HEAD) && \
    dotnet publish -v q /p:BuildNumber=$BUILD_NUMBER /p:CommitHash=$HOST_COMMIT src/WebJobs.Script.WebHost/WebJobs.Script.WebHost.csproj -c Release --output /azure-functions-host --runtime linux-arm64 --self-contained && \
    rm -rf /root/.local /root/.nuget /src /azure-functions-host/workers

RUN apt-get update && \
    apt-get install -y gnupg wget unzip && \
    EXTENSION_BUNDLE_VERSION_V2=2.12.1 && \
    EXTENSION_BUNDLE_FILENAME_V2=Microsoft.Azure.Functions.ExtensionBundle.${EXTENSION_BUNDLE_VERSION_V2}_linux-arm64.zip && \
    wget CUSTOM_STORAGE/$EXTENSION_BUNDLE_FILENAME_V2 && \
    mkdir -p /FuncExtensionBundles/Microsoft.Azure.Functions.ExtensionBundle/$EXTENSION_BUNDLE_VERSION_V2 && \
    unzip /$EXTENSION_BUNDLE_FILENAME_V2 -d /FuncExtensionBundles/Microsoft.Azure.Functions.ExtensionBundle/$EXTENSION_BUNDLE_VERSION_V2 && \
    rm -f /$EXTENSION_BUNDLE_FILENAME_V2 &&\
    EXTENSION_BUNDLE_VERSION_V3=3.9.1 && \
    EXTENSION_BUNDLE_FILENAME_V3=Microsoft.Azure.Functions.ExtensionBundle.${EXTENSION_BUNDLE_VERSION_V3}_linux-arm64.zip && \
    wget CUSTOM_STORAGE/$EXTENSION_BUNDLE_FILENAME_V3 && \
    mkdir -p /FuncExtensionBundles/Microsoft.Azure.Functions.ExtensionBundle/$EXTENSION_BUNDLE_VERSION_V3 && \
    unzip /$EXTENSION_BUNDLE_FILENAME_V3 -d /FuncExtensionBundles/Microsoft.Azure.Functions.ExtensionBundle/$EXTENSION_BUNDLE_VERSION_V3 && \
    rm -f /$EXTENSION_BUNDLE_FILENAME_V3 &&\
    find /FuncExtensionBundles/ -type f -exec chmod 644 {} \;

FROM arm64v8/python:3.9.12-slim-bullseye
ARG HOST_VERSION

ENV LANG=C.UTF-8 \
    ACCEPT_EULA=Y \
    AzureWebJobsScriptRoot=/home/site/wwwroot \
    HOME=/home \
    FUNCTIONS_WORKER_RUNTIME=python \
    ASPNETCORE_URLS=http://+:80 \
    DOTNET_RUNNING_IN_CONTAINER=true \
    DOTNET_USE_POLLING_FILE_WATCHER=true \
    HOST_VERSION=${HOST_VERSION} \
    ASPNETCORE_CONTENTROOT=/azure-functions-host

# Install Python dependencies
RUN apt-get update && \
    apt-get install -y wget && \
    echo 'debconf debconf/frontend select Noninteractive' | debconf-set-selections && \
    apt-get update && \
    apt-get install -y apt-transport-https curl gnupg && \
    # MSSQL dependencies
    # curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - && \
    # curl https://packages.microsoft.com/config/debian/11/prod.list > /etc/apt/sources.list.d/mssql-release.list && \
    # # Needed for libss1.0.0 and in turn MS SQL
    # echo 'deb http://security.debian.org/debian-security jessie/updates main' >> /etc/apt/sources.list && \
    # # install necessary locales for MS SQL
    # apt-get update && apt-get install -y locales && \
    # echo 'en_US.UTF-8 UTF-8' > /etc/locale.gen && \
    # locale-gen && \
    # # install MS SQL related packages
    # apt-get update && \
    # apt-get install -y unixodbc msodbcsql18 mssql-tools && \
    # .NET Core dependencies
    apt-get install -y --no-install-recommends ca-certificates \
    libc6 libgcc1 libgssapi-krb5-2 libicu67 libssl1.1 libstdc++6 zlib1g && \
    rm -rf /var/lib/apt/lists/* && \
    # Custom dependencies:
    #  OpenCV dependencies:
    apt-get update && \
    apt-get install -y libglib2.0-0 libsm6 libxext6 libxrender-dev && \
    #  binutils
    apt-get install -y binutils && \
    #  OpenMP dependencies
    apt-get install -y libgomp1 && \
    # mysql dependencies
    apt-get install -y default-libmysqlclient-dev
# Fix from https://github.com/GoogleCloudPlatform/google-cloud-dotnet-powerpack/issues/22#issuecomment-729895157
#apt-get install -y libc-dev

# This is current not working with the .NET 6.0 image based on bullseye. Tracking here: https://github.com/Azure/azure-functions-docker/issues/451
# Chrome headless dependencies
# https://github.com/puppeteer/puppeteer/blob/main/docs/troubleshooting.md#chrome-headless-doesnt-launch-on-unix
#RUN apt-get install -y xvfb gconf-service libasound2 libatk1.0-0 libc6 libcairo2 libcups2 \
#    libdbus-1-3 libexpat1 libfontconfig1 libgbm1 libgcc1 libgconf-2-4 libgdk-pixbuf2.0-0 libglib2.0-0 \
#    libgtk-3-0 libnspr4 libpango-1.0-0 libpangocairo-1.0-0 libstdc++6 libx11-6 libx11-xcb1 libxcb1 \
#    libxcomposite1 libxcursor1 libxdamage1 libxext6 libxfixes3 libxi6 libxrandr2 libxrender1 libxss1 \
#    libxtst6 ca-certificates fonts-liberation libappindicator1 libnss3 lsb-release xdg-utils wget

COPY --from=runtime-image ["/azure-functions-host", "/azure-functions-host"]
COPY --from=runtime-image ["/FuncExtensionBundles", "/FuncExtensionBundles" ]

RUN mkdir -p /azure-functions-host/workers/python/3.9/LINUX/Arm64 &&\
    apt install -y git &&\
    pip install grpcio-tools &&\
    pip install git+https://github.com/Azure/azure-functions-python-worker#egg=azure-functions-worker --target=/azure-functions-host/workers/python/3.9/LINUX/Arm64 &&\
    apt purge git -y &&\
    pip uninstall -y grpcio-tools

COPY ["worker.py", "/azure-functions-host/workers/python/3.9/LINUX/Arm64"]
COPY ["worker.config.json", "/azure-functions-host/workers/python" ]
COPY ["start.sh", "/azure-functions-host" ]
COPY ["sshd_config", "/etc/ssh/"]

ENV FUNCTIONS_WORKER_RUNTIME_VERSION=3.9

ENTRYPOINT ["/azure-functions-host/start.sh"]

ENV AzureWebJobsScriptRoot=/home/site/wwwroot \
    AzureFunctionsJobHost__Logging__Console__IsEnabled=true

WORKDIR $AzureWebJobsScriptRoot

COPY custom_app/requirements.txt .

RUN pip install -r requirements.txt

COPY start.sh /azure-functions-host

RUN chmod +x /azure-functions-host/start.sh

COPY custom_app .

[Ved2806]

Hi @vrdmr Could you please take a look into this issue?

[paldaniel]

Hi everyone, any update on this topic?

[liliankasem]

@vrdmr can someone on your team look into this issue?

[kurt-mueller-osumc]

It's been 1.5+ years since this issue was opened :(

[juergstaub]

It's been 1.5+ years since this issue was opened :(

Would need linux-arm64 as well :-(

[hallvictoria]

Hi all, sorry for the delay here. We've added support for Linux-Arm64 builds (see #1643 and #1686), which will be in runtime version 4.1041. This release will be starting soon, so I'd estimate 1-2 months for a full rollout. I'm not sure what the Core Tools release process is, but it lags behind the production updates.

Closing this issue for now as the work has been completed and tested but will check back & reopen if there are any issues. Thanks everyone for your patience!