feat(framework) Add alpine base image

.github/workflows/docker-base.yml

@@ -13,9 +13,6 @@ on:
 permissions:
   contents: read
 
-env:
-  DEFAULT_UBUNTU: 22.04
-
 jobs:
   parameters:
     name: Collect build parameters
@@ -24,7 +21,6 @@ jobs:
     outputs:
       pip-version: ${{ steps.versions.outputs.pip-version }}
       setuptools-version: ${{ steps.versions.outputs.setuptools-version }}
-      ubuntu-version: ${{ steps.versions.outputs.ubuntu-version }}
 
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
@@ -36,7 +32,6 @@ jobs:
         run: |
           echo "pip-version=${{ steps.bootstrap.outputs.pip-version }}" >> "$GITHUB_OUTPUT"
           echo "setuptools-version=${{ steps.bootstrap.outputs.setuptools-version }}" >> "$GITHUB_OUTPUT"
-          echo "ubuntu-version=${{ env.DEFAULT_UBUNTU }}" >> "$GITHUB_OUTPUT"
 
   build-base-images:
     name: Build base images
@@ -46,15 +41,19 @@ jobs:
       fail-fast: false
       matrix:
         python-version: ["3.8", "3.9", "3.10", "3.11"]
+        distro:
+          - name: ubuntu
+            version: 22.04
     with:
       namespace-repository: flwr/base
-      file-dir: src/docker/base
+      file-dir: src/docker/base/${{ matrix.distro.name }}
       build-args: |
         PYTHON_VERSION=${{ matrix.python-version }}
         PIP_VERSION=${{ needs.parameters.outputs.pip-version }}
         SETUPTOOLS_VERSION=${{ needs.parameters.outputs.setuptools-version }}
-        UBUNTU_VERSION=${{ needs.parameters.outputs.ubuntu-version }}
-      tags: py${{ matrix.python-version }}-ubuntu${{ needs.parameters.outputs.ubuntu-version }}
+        DISTRO=${{ matrix.distro.name }}
+        DISTRO_VERSION=${{ matrix.distro.version }}
+      tags: py${{ matrix.python-version }}-${{ matrix.distro.name }}${{ matrix.distro.version }}
     secrets:
       dockerhub-user: ${{ secrets.DOCKERHUB_USERNAME }}
       dockerhub-token: ${{ secrets.DOCKERHUB_TOKEN }}

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 +1,85 @@
+# Copyright 2024 Flower Labs GmbH. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+
+# Multi-stage base image 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/
+
+# hadolint global ignore=DL3018
+ARG PYTHON_VERSION=3.11
+ARG DISTRO=alpine
+ARG DISTRO_VERSION=3.19
+FROM python:${PYTHON_VERSION}-${DISTRO}${DISTRO_VERSION} as compile
+
+# Install system dependencies
+RUN apk add --no-cache \
+    # require for compiling grpcio on ARM64
+    g++ \
+    libffi-dev \
+    # create virtual env
+    && python -m venv /opt/venv
+
+# Make sure we use the virtualenv
+ENV PATH="/opt/venv/bin:$PATH"
+
+# Install specific version of pip, setuptools and flwr
+ARG PIP_VERSION
+ARG SETUPTOOLS_VERSION
+ARG FLWR_VERSION
+ARG FLWR_PACKAGE=flwr
+RUN pip install -U --no-cache-dir \
+    pip==${PIP_VERSION} \
+    setuptools==${SETUPTOOLS_VERSION} \
+    ${FLWR_PACKAGE}==${FLWR_VERSION}
+
+FROM python:${PYTHON_VERSION}-${DISTRO}${DISTRO_VERSION} as base
+
+# required by the grpc package
+RUN apk add --no-cache \
+    libstdc++
+
+COPY --from=compile /opt/venv /opt/venv
+
+# Make sure we use the virtualenv
+ENV PATH="/opt/venv/bin:$PATH" \
+    # Send stdout and stderr stream directly to the terminal. Ensures that no
+    # output is retained in a buffer if the application crashes.
+    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

src/docker/base/Dockerfile → src/docker/base/ubuntu/Dockerfile

@@ -1,7 +1,21 @@
-# Copyright 2023 Flower Labs GmbH. All Rights Reserved.
+# Copyright 2024 Flower Labs GmbH. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
 
-ARG UBUNTU_VERSION=22.04
-FROM ubuntu:$UBUNTU_VERSION as base
+ARG DISTRO=ubuntu
+ARG DISTRO_VERSION=22.04
+FROM $DISTRO:$DISTRO_VERSION as base
 
 ENV DEBIAN_FRONTEND noninteractive
 # Send stdout and stderr stream directly to the terminal. Ensures that no