1.. _showcase-sense-tutorial-bazel_cloud: 2 3============================== 413. Use Bazel's cloud features 5============================== 6.. caution:: 7 8 This section is optional. Feel free to skip to the next one if you're 9 impatient to :ref:`try the air quality app <showcase-sense-tutorial-prod>`! 10 11One of Bazel's defining features is that it's a cloud build system. Team 12members can easily `share artifacts 13<https://app.buildbuddy.io/invocation/f8bc4845-a38d-4c62-b939-14238168ba46>`__ 14(including test logs), builds can be run in parallel on hundreds of machines in 15the cloud, and build artifacts that were built once (by anyone) don't need to 16be rebuilt from scratch. 17 18This section gives you a taste of these features of Bazel using `BuildBuddy 19<https://www.buildbuddy.io/>`_. 20 21---------------- 22BuildBuddy setup 23---------------- 24To use cloud features, you need to get set up with some cloud provider. 25 26.. note:: 27 28 Googlers: see additional instructions at `go/pw-sense-googlers 29 <http://go/pw-sense-googlers#buildbuddy-integration>`_. 30 31#. Go to https://app.buildbuddy.io/ and log in via Google or GitHub. 32#. Click `Quickstart Guide <https://app.buildbuddy.io/docs/setup/>`__. 33#. In **1. Configure your .bazelrc** enable the following options: 34 35 * API Key 36 * Enable cache 37 * Full cache 38 39 .. caution:: 40 41 :bug:`364781685`: Sense does not support remote execution yet, so don't 42 enable that option. 43 44#. Copy the provided snippet to your ``.bazelrc``. 45 46--------------------- 47Review and share logs 48--------------------- 49Let's go back to what we learned in :ref:`showcase-sense-tutorial-hosttests` and run a test. 50 51#. Open ``//modules/blinky/blinky_test.cc``. 52 53#. Make the ``Toggle`` test fail by changing one of the expected values. 54 Example: 55 56 .. code-block:: c++ 57 58 TEST_F(BlinkyTest, Toggle) { 59 // ... 60 auto event = FirstActive(); 61 ASSERT_NE(event, monochrome_led_.events().end()); 62 EXPECT_EQ(event->state, State::kInactive); // add this line 63 // EXPECT_EQ(event->state, State::kActive); // comment out this line 64 EXPECT_GE(ToMs(event->timestamp - start), kIntervalMs * 0); 65 start = event->timestamp; 66 // ... 67 } 68 69 .. caution:: Remember to save your changes! 70 .. tab-set:: 71 72 .. tab-item:: VS Code 73 :sync: vsc 74 75 In **Bazel Build Targets** expand **//modules/blinky**, then right-click 76 **:blinky_test (cc_test)**, then select **Test target**. 77 78 .. figure:: https://storage.googleapis.com/pigweed-media/sense/20240802/test_target_v2.png 79 :alt: Selecting Test target 80 81 Starting ``blinky_test`` 82 83 A task launches a terminal. You should see ``blinky_test`` fail, and a 84 BuildBuddy invocation link printed: 85 86 .. code-block:: console 87 88 //modules/blinky:blinky_test FAILED in 0.4s 89 INFO: Streaming build results to: https://app.buildbuddy.io/invocation/f8bc4845-a38d-4c62-b939-14238168ba46 90 91 .. tab-item:: CLI 92 :sync: cli 93 94 Run the following command. You should see output similar to what's 95 shown after the command. The key line starts with ``INFO: Streaming 96 build results to:``. It contains the BuildBuddy invocation link. 97 98 .. code-block:: console 99 100 $ bazelisk test //modules/blinky:blinky_test 101 # ... 102 //modules/blinky:blinky_test FAILED in 0.4s 103 /home/kayce/.cache/bazel/_bazel_kayce/27fcdd448f61589ce2692618b3237728/execroot/showcase-rp2/bazel-out/k8-fastbuild/testlogs/modules/blinky/blinky_test/test.log 104 105 Executed 1 out of 1 test: 1 fails locally. 106 INFO: Streaming build results to: https://app.buildbuddy.io/invocation/f8bc4845-a38d-4c62-b939-14238168ba46 107 108#. Click the provided link. Some highlights to notice: 109 110 * The full log of the failed test. 111 * The command line invocation used to generate it. 112 * A timing profile showing how long Bazel took to build and execute the test. 113 114#. Click "Share" (in the top-right corner) and broaden the permissions to make 115 the invocation link shareable. Then show it off to your friends and 116 coworkers! 117 118-------------- 119Remote caching 120-------------- 121Bazel supports remote caching: if you (or someone else in your organization) 122already built an artifact, you can simply retrieve it from the cache instead of 123building it from scratch. Let's test it out. 124 125 126#. Remove all local Bazel build results. 127 128 .. code-block:: console 129 130 $ bazelisk clean 131 132#. Run ``blinky_test`` again. It should be quite fast, even though you 133 discarded all the build artifacts. Bazel simply downloads them from the 134 remote cache that your previous invocation populated! 135 136 You can click the **CACHE** tab in the BuildBuddy invocation UI to see more 137 details on cache performance (how many hits there were, how much data was 138 uploaded and downloaded, etc). 139 140------- 141Summary 142------- 143In this section, you've gotten a taste of the cloud features of Bazel: 144generating easily shareable URLs for build and test invocations, and speeding 145up your builds by leveraging remote caching. 146 147Next, head over to :ref:`showcase-sense-tutorial-prod` to try 148out the air quality monitoring application. 149
