Add support for building android_device and testing android_instrumen…

…tation_test emulator tests on RBE (android#310)

* Add support for building android_device and testing android_instrumentation_test emulator tests on RBE

* Address philwo's comments

* Update base docker image version and --jobs

.bazelrc

@@ -20,4 +20,55 @@ test --flaky_test_attempts=3
 
 # The unified launcher runs in Python 2 host configuration
 # https://github.com/bazelbuild/bazel/issues/7899
-build --host_force_python=PY2 
+build --host_force_python=PY2
+
+# ------------------------
+# General RBE configuration
+# ------------------------
+build:remote --jobs=100
+
+# Java toolchain setup
+build:remote --java_toolchain=@bazel_tools//tools/jdk:toolchain_hostjdk8
+build:remote --host_java_toolchain=@bazel_tools//tools/jdk:toolchain_hostjdk8
+build:remote --host_javabase=@rbe_default//java:jdk
+build:remote --javabase=@rbe_default//java:jdk
+
+# C++ toolchain setup
+build:remote --extra_toolchains=@rbe_default//config:cc-toolchain
+build:remote --crosstool_top=@rbe_default//cc:toolchain
+
+# Remote instance setup
+build:remote --remote_instance_name=projects/bazel-untrusted/instances/default_instance
+build:remote --project_id=bazel-untrusted
+
+# Set various strategies so that all actions execute remotely. Mixing remote
+# and local execution will lead to errors unless the toolchain and remote
+# machine exactly match the host machine.
+build:remote --spawn_strategy=remote
+build:remote --define=EXECUTOR=remote
+
+# Enable the remote cache so action results can be shared across machines,
+# developers, and workspaces.
+build:remote --remote_cache=remotebuildexecution.googleapis.com
+
+# Enable remote execution so actions are performed on the remote systems.
+build:remote --remote_executor=remotebuildexecution.googleapis.com
+
+# Enable authentication. This will pick up application default credentials by
+# default.
+build:remote --google_default_credentials
+
+# -------------------------------------------
+# Custom RBE configuration for Android builds
+# -------------------------------------------
+
+build:remote_android --config=remote  # Reuse general configuration
+
+# Platform configuration
+build:remote_android --extra_execution_platforms=:android_platform
+build:remote_android --host_platform=:android_platform
+build:remote_android --platforms=:android_platform
+
+build:remote_android --strategy=DexBuilder=remote
+build:remote_android --noexperimental_check_desugar_deps # Workaround for singlejar incompatibility with RBE
+build:remote_android --incompatible_strict_action_env

BUILD.bazel

@@ -21,3 +21,30 @@ android_library(
         artifact("org.hamcrest:java-hamcrest"),
     ],
 )
+
+# Platform configuration for emulators on RBE for Bazel CI
+platform(
+    name = "android_platform",
+    constraint_values = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:linux",
+        "@bazel_toolchains//constraints:xenial",
+        "@bazel_tools//tools/cpp:clang",
+    ],
+    # TODO(@jin): s/di-cloud-exp/rbe-containers/ when the official android-test container with libxcursor1 and libxcomposite1 is ready.
+    # URI for official container: docker://gcr.io/rbe-containers/ubuntu16_04-android_test@sha256:<sha256>
+    remote_execution_properties = """
+        properties: {
+            name: "container-image"
+            value: "docker://gcr.io/di-cloud-exp/rbe-ubuntu16-04-android@sha256:eb3828f71faf595f44b20b97d205e73e8a21982f1d7a170c3ec8f9d33ce3179a"
+        }
+        properties: {
+            name: "dockerNetwork"
+            value: "standard"
+        }
+        properties: {
+            name: "dockerPrivileged"
+            value: "true"
+        }
+""",
+)

WORKSPACE

@@ -9,6 +9,9 @@ android_sdk_repository(
     # path = "/path/to/sdk",
 )
 
+# Required for running emulator tests on RBE on Bazel CI
+android_ndk_repository(name = "androidndk")
+
 # Android Test Support
 #
 # This repository contains the supporting tools to run Android instrumentation tests,
@@ -95,3 +98,20 @@ maven_install(
     jetify = True,
     version_conflict_policy = "pinned",
 )
+
+http_archive(
+    name = "bazel_toolchains",
+    sha256 = "4d348abfaddbcee0c077fc51bb1177065c3663191588ab3d958f027cbfe1818b",
+    strip_prefix = "bazel-toolchains-2.1.0",
+    urls = [
+        "https://github.com/bazelbuild/bazel-toolchains/releases/download/2.1.0/bazel-toolchains-2.1.0.tar.gz",
+        "https://mirror.bazel.build/github.com/bazelbuild/bazel-toolchains/archive/2.1.0.tar.gz",
+    ],
+)
+
+load("@bazel_toolchains//rules:rbe_repo.bzl", "rbe_autoconfig")
+
+rbe_autoconfig(name = "rbe_default")
+
+# RBE support for android_device and android_instrumentation_test on RBE.
+register_execution_platforms(":android_platform")

bazelci/buildkite-pipeline.yml

@@ -5,19 +5,17 @@ platforms:
     build_targets:
     - "//..."
     test_flags:
-    - "--local_test_jobs=8" # Run at most 8 tests (= emulators) in parallel
-    - "--flaky_test_attempts=3" # Flakes.
-    - "--spawn_strategy=standalone" # Reduce flakes.
+    - "--config=remote_android"
+    - "--flaky_test_attempts=3"
     test_targets:
     - "//..."
     - "-//ui/espresso/AccessibilitySample/..."
   ubuntu1804:
     build_targets:
     - "//..."
     test_flags:
-    - "--local_test_jobs=8" # Run at most 8 tests (= emulators) in parallel
-    - "--flaky_test_attempts=3" # Flakes.
-    - "--spawn_strategy=standalone" # Reduce flakes.
+    - "--config=remote_android"
+    - "--flaky_test_attempts=3"
     test_targets:
     - "//..."
     - "-//ui/espresso/AccessibilitySample/..."