feat(framework:ci) add alpine base image

Signed-off-by: Robert Steiner <robert@flower.ai>

.github/workflows/docker-base.yml

@@ -48,7 +48,7 @@ jobs:
         python-version: ["3.8", "3.9", "3.10", "3.11"]
     with:
       namespace-repository: flwr/base
-      file-dir: src/docker/base
+      file-dir: src/docker/base/ubuntu
       build-args: |
         PYTHON_VERSION=${{ matrix.python-version }}
         PIP_VERSION=${{ needs.parameters.outputs.pip-version }}

doc/source/contributor-how-to-build-docker-images.rst

@@ -66,7 +66,7 @@ The following example creates a base image with Python 3.11.0, pip 23.0.1 and se
 
 .. code-block:: bash
 
-  $ cd src/docker/base/
+  $ cd src/docker/base/ubuntu
   $ docker build \
     --build-arg PYTHON_VERSION=3.11.0 \
     --build-arg PIP_VERSION=23.0.1 \

src/docker/base/alpine/Dockerfile

@@ -0,0 +1,71 @@
+# Copyright 2024 Flower Labs GmbH. All Rights Reserved.
+
+# Multi-stage base build
+#
+# Building the base image for ARM64 requires installing some additional system dependencies to
+# compile the grpcio package, as they do not provide a pre-built package. However, we don't want
+# the dependencies in the final base image as they are only needed to compile the package.
+# That's why we're creating a multi-stage build. When installing the flwr, we are using a
+# virtual environment to keep all files in a single isolated directory as described here:
+# https://pythonspeed.com/articles/multi-stage-docker-python/
+
+ARG PYTHON_VERSION=3.11
+ARG ALPINE_VERSION=alpine3.19
+FROM python:${PYTHON_VERSION}-${ALPINE_VERSION} as compile
+
+# Install system dependencies
+RUN apk add --no-cache \
+    # require for compiling grpcio on ARM64
+    g++=13.2.1_git20231014-r0 \
+    libffi-dev=3.4.4-r3 \
+    # create virtual env
+    && python -m venv /opt/venv
+
+# Make sure we use the virtualenv
+ENV PATH="/opt/venv/bin:$PATH"
+
+# Install specific version of pip, setuptools and flwr
+ARG PIP_VERSION
+ARG SETUPTOOLS_VERSION
+ARG FLWR_PACKAGE=flwr
+ARG FLWR_VERSION
+RUN pip install -U --no-cache-dir \
+    pip==${PIP_VERSION} \
+    setuptools==${SETUPTOOLS_VERSION} \
+    ${FLWR_PACKAGE}==${FLWR_VERSION}
+
+FROM python:${PYTHON_VERSION}-${ALPINE_VERSION} as base
+
+# required by the grpc package
+RUN apk add --no-cache \
+    libstdc++=13.2.1_git20231014-r0
+
+COPY --from=compile /opt/venv /opt/venv
+
+# Make sure we use the virtualenv:
+ENV PATH="/opt/venv/bin:$PATH"
+
+# Send stdout and stderr stream directly to the terminal. Ensures that no
+# output is retained in a buffer if the application crashes.
+ENV PYTHONUNBUFFERED=1 \
+    # Typically, bytecode is created on the first invocation to speed up following invocation.
+    # However, in Docker we only make a single invocation (when we start the container).
+    # Therefore, we can disable bytecode writing.
+    PYTHONDONTWRITEBYTECODE=1 \
+    # Ensure that python encoding is always UTF-8.
+    PYTHONIOENCODING=UTF-8 \
+    LANG=C.UTF-8 \
+    LC_ALL=C.UTF-8
+
+# add non-root user
+RUN adduser \
+    --no-create-home \
+    --disabled-password \
+    --gecos "" \
+    --uid 49999 app \
+    && mkdir -p /app \
+    && chown -R app:app /app
+
+WORKDIR /app
+USER app
+ENV HOME=/app