Extract out Android build instructions (#1191)

This is the first part towards removing the dependency on Docker from our build instructions for Linux desktop and Android (#1181). This commit makes it clear that you can build 'libmozc.so' on both Linux and macOS by the same Bazel command with actually demonstrating it in .github/workflows/android.yaml that 'libmozc.so' can be built on both Linux and macOS GitHub Actions runners. With above our 'Dockerfile' can stop setting up Android NDK since 'build_mozc_in_docker.md' does not mention Android any more. This commit is only about the build instructions of 'libmozc.so' for Android. There must be no difference in the final artifacts. PiperOrigin-RevId: 729468755
google · Feb 21, 2025 · f215eaf · f215eaf
1 parent 5c0b4bd
commit f215eaf
Show file tree

Hide file tree

Showing 7 changed files with 153 additions and 32 deletions.
diff --git a/.github/workflows/android.yaml b/.github/workflows/android.yaml
@@ -1,5 +1,5 @@
 name: CI for Android
-# https://github.com/google/mozc/blob/master/docs/build_mozc_in_docker.md
+# https://github.com/google/mozc/blob/master/docs/build_mozc_for_android.md
 
 # Run on push.
 on: push
@@ -11,8 +11,11 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
+env:
+  PYTHON_VENV_ROOT: ${{ github.workspace }}/src/python-venv
+
 jobs:
-  build:
+  build_on_linux:
     # https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2404-Readme.md
     runs-on: ubuntu-24.04
     timeout-minutes: 60
@@ -27,6 +30,25 @@ jobs:
         run: |
           sudo apt-get update
 
+      - name: Setup Python
+        run: |
+          python3 -m venv ${PYTHON_VENV_ROOT}
+          source ${PYTHON_VENV_ROOT}/bin/activate
+          python3 -m pip install requests
+
+      - name: Try to restore update_deps cache
+        uses: actions/cache@v4
+        with:
+          path: src/third_party_cache
+          key: update_deps-${{ runner.os }}-${{ hashFiles('src/build_tools/update_deps.py') }}
+
+      - name: Install dependencies
+        working-directory: ./src
+        # This command uses src/third_party_cache as the download cache.
+        run: |
+          source ${PYTHON_VENV_ROOT}/bin/activate
+          python3 build_tools/update_deps.py
+
       - name: build
         working-directory: ./src
         run: |
@@ -38,3 +60,38 @@ jobs:
           name: native_libs.zip
           path: src/bazel-bin/android/jni/native_libs.zip
           if-no-files-found: warn
+
+  build_on_mac:
+    # https://github.com/actions/runner-images/blob/main/images/macos/macos-14-arm64-Readme.md
+    runs-on: macos-14
+    timeout-minutes: 60
+
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: 'recursive'
+
+      - name: Setup Python
+        run: |
+          python3 -m venv ${PYTHON_VENV_ROOT}
+          source ${PYTHON_VENV_ROOT}/bin/activate
+          python3 -m pip install requests
+
+      - name: Try to restore update_deps cache
+        uses: actions/cache@v4
+        with:
+          path: src/third_party_cache
+          key: update_deps-${{ runner.os }}-${{ hashFiles('src/build_tools/update_deps.py') }}
+
+      - name: Install dependencies
+        working-directory: ./src
+        # This command uses src/third_party_cache as the download cache.
+        run: |
+          source ${PYTHON_VENV_ROOT}/bin/activate
+          python3 build_tools/update_deps.py
+
+      - name: build
+        working-directory: ./src
+        run: |
+          bazelisk build --config oss_android package --config release_build
diff --git a/README.md b/README.md
@@ -34,9 +34,10 @@ Detailed differences between Google Japanese Input and Mozc are described in [Ab
 Build Instructions
 ------------------
 
-* [How to build Mozc in Docker](docs/build_mozc_in_docker.md): Android library and Linux desktop builds.
-* [How to build Mozc in macOS](docs/build_mozc_in_osx.md): macOS build.
-* [How to build Mozc in Windows](docs/build_mozc_in_windows.md): Windows build.
+* [How to build Mozc for Android](docs/build_mozc_for_docker.md): for Android library (`libmozc.so`)
+* [How to build Mozc for Linux](docs/build_mozc_in_docker.md): for Linux desktop
+* [How to build Mozc for macOS](docs/build_mozc_in_osx.md): for macOS build
+* [How to build Mozc for Windows](docs/build_mozc_in_windows.md): for Windows
 
 Release Plan
 ------------

diff --git a/docker/ubuntu22.04/Dockerfile b/docker/ubuntu22.04/Dockerfile
@@ -61,11 +61,6 @@ RUN curl -LO https://github.com/bazelbuild/bazelisk/releases/download/v1.25.0/ba
   && mv bazelisk-linux-amd64 /home/mozc_builder/bin/bazelisk \
   && chmod u+x /home/mozc_builder/bin/bazelisk
 
-## Set up Android NDK
-## https://github.com/android/ndk/wiki/Home/24fe2d7ee3591346e0e8ae615977a15c0a4fba40#ndk-r28
-RUN curl -LO https://dl.google.com/android/repository/android-ndk-r28-linux.zip && unzip android-ndk-r28-linux.zip && rm android-ndk-r28-linux.zip
-ENV ANDROID_NDK_HOME /home/mozc_builder/work/android-ndk-r28
-
 # 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/

diff --git a/docker/ubuntu24.04/Dockerfile b/docker/ubuntu24.04/Dockerfile
@@ -57,11 +57,6 @@ RUN curl -LO https://github.com/bazelbuild/bazelisk/releases/download/v1.25.0/ba
   && mv bazelisk-linux-amd64 /home/mozc_builder/bin/bazelisk \
   && chmod u+x /home/mozc_builder/bin/bazelisk
 
-## Set up Android NDK
-## https://github.com/android/ndk/wiki/Home/24fe2d7ee3591346e0e8ae615977a15c0a4fba40#ndk-r28
-RUN curl -LO https://dl.google.com/android/repository/android-ndk-r28-linux.zip && unzip android-ndk-r28-linux.zip && rm android-ndk-r28-linux.zip
-ENV ANDROID_NDK_HOME /home/mozc_builder/work/android-ndk-r28
-
 # 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/

diff --git a/docs/build_mozc_for_android.md b/docs/build_mozc_for_android.md
@@ -0,0 +1,86 @@
+# How to build `libmozc.so` for Android
+
+[![Android lib](https://github.com/google/mozc/actions/workflows/android.yaml/badge.svg)](https://github.com/google/mozc/actions/workflows/android.yaml)
+
+## Summary
+
+If you are not sure what the following commands do, please check the descriptions below
+and make sure the operations before running them.
+
+```
+git clone https://github.com/google/mozc.git
+cd mozc/src
+
+export PYTHON_VENV_ROOT=${PWD}/python-venv
+python3 -m venv ${PYTHON_VENV_ROOT}
+source ${PYTHON_VENV_ROOT}/bin/activate
+python3 -m pip install requests
+
+python3 build_tools/update_deps.py
+
+bazelisk build package --config oss_android --config release_build
+```
+
+Client code for Android apk is deprecated.
+(the last revision with Android client code is
+[afb03dd](https://github.com/google/mozc/commit/afb03ddfe72dde4cf2409863a3bfea160f7a66d8)).
+
+## Setup
+
+### System Requirements
+
+Currently macOS and Linux are tested to build `libmozc.so` for Android.
+
+### Software Requirements
+
+Building `libmozc.so` for Android requires the following software.
+
+ * [bazelisk](https://github.com/bazelbuild/bazelisk)
+ * C++ compiler (GCC or clang)
+ * Python 3.9 or later with the following pip module.
+   * `requests`
+
+## Build instructions
+
+### Get the Code
+
+You can download Mozc source code as follows:
+
+```
+git clone https://github.com/google/mozc.git
+cd mozc/src
+```
+
+Hereafter you can do all the operations without changing directory.
+
+### Set up and enable Python virtual environment
+
+The following commands set up Python virtual environment under `mozc/src/python-venv`.
+
+```
+export PYTHON_VENV_ROOT=${PWD}/python-venv
+python3 -m venv ${PYTHON_VENV_ROOT}
+source ${PYTHON_VENV_ROOT}/bin/activate
+python3 -m pip install requests
+```
+
+Using `mozc/src/python-venv` as the virtual environment location is not mandatory. Any other location should also work.
+
+### Check out additional build dependencies
+
+```
+python build_tools/update_deps.py
+```
+
+In this step, additional build dependencies will be downloaded.
+
+  * [Android NDK r28](https://github.com/android/ndk/wiki/Home/24fe2d7ee3591346e0e8ae615977a15c0a4fba40#ndk-r28)
+  * [git submodules](../.gitmodules)
+
+### Build `libmozc.so` for Android
+
+```
+bazelisk build package --config oss_android --config release_build
+```
+
+`package` is an alias to build `android/jni:native_libs`.
diff --git a/docs/build_mozc_in_docker.md b/docs/build_mozc_in_docker.md
@@ -19,7 +19,7 @@ docker cp mozc_build:/home/mozc_builder/work/mozc/src/bazel-bin/unix/mozc.zip .
 ```
 
 ## Introduction
-Docker containers are available to build Mozc binaries for Android JNI library and Linux desktop.
+Docker containers are available to build Mozc binaries for Linux desktop.
 
 ## System Requirements
 Currently, only Ubuntu 24.04 is tested to host the Docker container to build Mozc.
@@ -186,22 +186,6 @@ If the issue persists, also try the following command to [clean Bazel's build ca
 bazelisk clean --expunge
 ```
 
-## Build Mozc library for Android:
-
-Client code for Android apk is deprecated.
-(the last revision with Android client code is
-[afb03dd](https://github.com/google/mozc/commit/afb03ddfe72dde4cf2409863a3bfea160f7a66d8)).
-
-The conversion engine for Android is built with Bazel.
-
-```
-bazelisk build package --config oss_android
-```
-
-`package` is an alias to build `android/jni:native_libs`.
-
-We have tested Android NDK r27. The former versions may not work.
-
 -----
 
 ## Build Mozc for Linux Desktop with GYP (deprecated):

diff --git a/src/MODULE.bazel b/src/MODULE.bazel
@@ -129,6 +129,9 @@ android_ndk_repository_extension = use_extension(
     "@rules_android_ndk//:extension.bzl",
     "android_ndk_repository_extension",
 )
+android_ndk_repository_extension.configure(
+    path = "$WORKSPACE_ROOT/third_party/ndk/android-ndk-r28",
+)
 use_repo(android_ndk_repository_extension, "androidndk")
 
 register_toolchains("@androidndk//:all")