したいこと

Google製のオープンソースIMEのmozcのAndroidビルドを行いたい．

詰まったところ

公式ドキュメントによればDockerfileを用いてDockerコンテナを作成しそのうえでbazelというビルドツールを用いてビルドすれば変換エンジンがビルドできるらしい(クライアントのビルドは非推奨)

curl -O https://raw.githubusercontent.com/google/mozc/master/docker/ubuntu20.04/Dockerfile
sudo docker build --rm -t $USER/mozc_ubuntu20.04 .
sudo docker run --interactive --tty --rm $USER/mozc_ubuntu20.04
bazel build android/jni:mozc_lib --config oss_android

しかし実際にやってみると以下のようなエラーが出る(コミットハッシュ667db549e000778e9b08749326086b6bec58cad0)

Extracting Bazel installation...
Starting local Bazel server and connecting to it...
ERROR: Analysis of target '//android/jni:mozc_lib' failed; build aborted: Either the path attribute of android_sdk_repository or the ANDROID_HOME environment variable must be set.
INFO: Elapsed time: 12.774s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (5 packages loaded, 6 targets configured)
    currently loading: @bazel_tools//tools/python ... (2 packages)
    Fetching @local_config_cc_toolchains; Restarting.

解決策

公式のを修正した以下のDockerfileを用いる

Dockerfile# Copyright 2010-2020, Google Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
#     * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
#     * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

FROM ubuntu:20.04

ENV DEBIAN_FRONTEND noninteractive

# Package installation
RUN apt-get update
## Common packages for linux build environment
RUN apt install -y wget clang libc++-dev libc++abi-dev python python-six python3-six pkg-config git curl bzip2 unzip make ninja-build
## Packages for linux desktop version
RUN apt install -y libibus-1.0-dev libglib2.0-dev qtbase5-dev libgtk2.0-dev libxcb-xfixes0-dev
## Packages for Android
RUN apt install -y --no-install-recommends openjdk-8-jdk openjdk-8-jre-headless libjsr305-java ant zip libc6-i386 lib32stdc++6 lib32ncurses6 lib32z1
## Packages for NaCl
RUN apt install -y libc6-i386 lib32stdc++6
## For emacsian
RUN apt install -y emacs

## For Bazel
## https://docs.bazel.build/versions/master/install-ubuntu.html
RUN apt install -y curl gnupg libncurses5
RUN curl -fsSL https://bazel.build/bazel-release.pub.gpg | gpg --dearmor > bazel.gpg
RUN mv bazel.gpg /etc/apt/trusted.gpg.d/
RUN echo "deb [arch=amd64] https://storage.googleapis.com/bazel-apt stable jdk1.8" | tee /etc/apt/sources.list.d/bazel.list
RUN apt update
RUN apt install -y bazel

# Working environemnt
ENV HOME /home/mozc_builder
RUN useradd --create-home --shell /bin/bash --base-dir /home mozc_builder
USER mozc_builder
RUN mkdir -p /home/mozc_builder/work
WORKDIR /home/mozc_builder/work

## For Android SDK/NDK
RUN curl -LO http://dl.google.com/android/repository/android-ndk-r21b-linux-x86_64.zip && unzip android-ndk-r21b-linux-x86_64.zip && rm android-ndk-r21b-linux-x86_64.zip
ENV ANDROID_NDK_HOME /home/mozc_builder/work/android-ndk-r21b
# RUN curl -L http://dl.google.com/android/android-sdk_r24.1.2-linux.tgz | tar -zx
ENV ANDROID_HOME /home/mozc_builder/work/android-sdk-linux
ENV SDK_TOOL_VERSION=sdk-tools-linux-4333796
ENV BUILD_TOOLS_VERSION=28.0.3
ENV PLATFORMS_VERSION=android-28
ENV PATH=$PATH:$ANDROID_HOME/tools:$ANDROID_HOME/tools/bin
# install android sdk tools
RUN mkdir $ANDROID_HOME && \
  wget "https://dl.google.com/android/repository/${SDK_TOOL_VERSION}.zip" && \
  unzip -d $ANDROID_HOME $SDK_TOOL_VERSION.zip && \
  rm -rf $SDK_TOOL_VERSION.zip
# agree sdkmanager licenses
RUN mkdir ~/.android && \
    touch ~/.android/repositories.cfg
RUN yes | sdkmanager --licenses
# install android tools and more
RUN sdkmanager "tools" "build-tools;${BUILD_TOOLS_VERSION}" "platforms;${PLATFORMS_VERSION}" "platform-tools" "extras;android;m2repository"
# ENV PATH $PATH:${ANDROID_HOME}/tools:${ANDROID_HOME}/platform-tools:${ANDROID_NDK_HOME}
# RUN echo y | android update sdk --all --force --no-ui --filter android-22
# RUN echo y | android update sdk --all --force --no-ui --filter build-tools-22.0.0
# RUN echo y | android update sdk --all --force --no-ui --filter platform-tool
# RUN mkdir -p ${ANDROID_HOME}/extras/android
# RUN curl -LO https://dl.google.com/dl/android/repository/support_r23.1.1.zip && unzip -d ${ANDROID_HOME}/extras/android support_r23.1.1.zip support/v13/android-support-v13.jar && rm support_r23.1.1.zip

## depot_tools for Ninja prebuilt
RUN git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
ENV PATH $PATH:/home/mozc_builder/work/depot_tools

# check out Mozc source with submodules
RUN mkdir /home/mozc_builder/work/mozc
# COPY --chown=mozc_builder:mozc_builder src/ /home/mozc_builder/work/mozc/src/
RUN git clone https://github.com/google/mozc.git -b master --single-branch --recursive

WORKDIR /home/mozc_builder/work/mozc/src
ENTRYPOINT bash

このDockerfileがあるディレクトリ上で公式と同じ以下のコマンドを入力する．

sudo docker build --rm -t $USER/mozc_ubuntu20.04 .
sudo docker run --interactive --tty --rm $USER/mozc_ubuntu20.04

Dockerコンテナ内でbazelを用いてビルドする

bazel build android/jni:mozc_lib --config oss_android

別でターミナルを開いてコンテナ内に生成されたビルドファイルをディレクトリごとホストにコピーする

mkdir bazel-bin
sudo docker cp ${container_id}:/home/mozc_builder/work/mozc/src/bazel-bin/. bazel-bin/
mkdir basel-out
sudo docker cp ${container_id}:/home/mozc_builder/work/mozc/src/bazel-out/. bazel-out/
mkdir basel-src
sudo docker cp ${container_id}:/home/mozc_builder/work/mozc/src/bazel-src/. bazel-src/

一応すべてコピーしたがおそらく必要なものはbazel-bin/android/jni/libmozc.soファイルだけな気がする