Ogrenich Bazel

Prepare Environment

Install Bazelisk 1.4.0 as Bazel through Homebrew:

brew install bazelisk@1.4.0
ln -s /user/local/Cellar/bazelisk/1.4.0/bin/bazelisk /user/local/bin/bazel

iOS

1. Create a new Xcode project. iOS Single View App (Swift, Storyboards, Include Unit and UI Tests).

[Optional] (Carthage) Create a new Cartfile file with dependencies and run:

carthage bootstrap --platform iOS

2. Create a new WORKSPACE file with base dependencies.

3. Create a new BUILD file for the main target.

[Optional] (Carthage) Create an additional BUILD file in the root directory of the iOS project with imports of dynamic frameworks.

4. Update some env values in your main target's Info.plist file:

CFBundlePackageType: $(PRODUCT_BUNDLE_PACKAGE_TYPE) -> APPL
UISceneDelegateClassName: $(PRODUCT_MODULE_NAME).SceneDelegate -> *_Sources.SceneDelegate

5. Add a new .bazelversion and specify exact version of Bazel in it. Additionally add a new .bazelrc with predefined build flags for iOS.

6.1. Fetch and Compile core Bazel’s dependencies:

bazel build @build_bazel_rules_swift//examples/xplatform/hello_world

6.2. Fetch external Bazel’s dependencies:

bazel fetch //*:*

6.3. Build project with Bazel:

bazel build //*:* --spawn_strategy=local --apple_platform_type=ios --cpu=ios_x86_64

7. Build iOS App with Bazel completed successfully! 🎉

8. Install Tulsi 0.20200219.88 – Xcode Project Generator For Bazel: https://github.com/bazelbuild/tulsi#building-and-installing.

9. Remove *.xcodeproj.

10. Create a new *.tulsiproj and save it on the same level with WORKSPACE file.

11. Add */BUILD file associated with the project as a Package to the created Tulsi's project. Repeat this step if you have more than one BUILD file containing targets you wish to build directly.

12. Next, you have to select one or more targets that you want to build in Xcode, for example * - ios_application and Sources – swift_library.

13. Select one or more Source Targets with a Recursive strategy (Optional). This allows you to select a working set from your full source tree that best matches the portion of the project that you're likely to edit. Save a new Config with the Default name.

14. Generate a new Xcode Project with Tulsi and save it on the same level with WORKSPACE and *.tulsiproj files.

Finally, build and run your * App with Bazel in Xcode. 🍾

iOS Build Benchmarks 👷

1. Cold Build iOS App (Carthage) with Xcode.

Build time: 11.592s

2. Cold Build with Bazel without Remote Cache.

Elapsed time: 7.829s

INFO: Analyzed target //Bazel:Bazel (0 packages loaded, 196 targets configured).
INFO: Found 1 target...
INFO: From ImportedDynamicFrameworkProcessor Bazel/Bazel-intermediates/_imported_frameworks/Kingfisher.framework.zip:
bazel-out/ios_x86_64-fastbuild/bin/Bazel/Bazel-intermediates/_imported_frameworks/Kingfisher.framework: replacing existing signature
Target //Bazel:Bazel up-to-date:
  bazel-bin/Bazel/Bazel.ipa
INFO: Elapsed time: 7.829s, Critical Path: 7.51s
INFO: 15 processes: 15 local.
INFO: Build completed successfully, 44 total actions

3. Cold Build with Bazel + Upload Actions and Outputs to Remote Cache.

Elapsed time: 7.864s

INFO: Invocation ID: *
INFO: Analyzed target //Bazel:Bazel (0 packages loaded, 196 targets configured).
INFO: Found 1 target...
INFO: From ImportedDynamicFrameworkProcessor Bazel/Bazel-intermediates/_imported_frameworks/Kingfisher.framework.zip:
bazel-out/ios_x86_64-fastbuild/bin/Bazel/Bazel-intermediates/_imported_frameworks/Kingfisher.framework: replacing existing signature
Target //Bazel:Bazel up-to-date:
  bazel-bin/Bazel/Bazel.ipa
INFO: Elapsed time: 7.864s, Critical Path: 7.11s
INFO: 15 processes: 15 local.
INFO: Build completed successfully, 44 total actions

4. Cold Build with Bazel + Retrieve Actions and Outputs from Remote Cache.

Elapsed time: 1.614s

INFO: Invocation ID: *
INFO: Analyzed target //Bazel:Bazel (0 packages loaded, 196 targets configured).
INFO: Found 1 target...
INFO: From ImportedDynamicFrameworkProcessor Bazel/Bazel-intermediates/_imported_frameworks/Kingfisher.framework.zip:
bazel-out/ios_x86_64-fastbuild/bin/Bazel/Bazel-intermediates/_imported_frameworks/Kingfisher.framework: replacing existing signature
Target //Bazel:Bazel up-to-date:
  bazel-bin/Bazel/Bazel.ipa
INFO: Elapsed time: 1.614s, Critical Path: 1.26s
INFO: 15 processes: 14 remote cache hit, 1 local.
INFO: Build completed successfully, 44 total actions

Result: Bazel with Remote Cache a little bit faster than original Xcode build system. Overall speedup from local Bazel build to Remote Cache is ~x7 faster 🚀