1.. _showcase-sense-tutorial-bazel_cloud: 2 3============================== 413. Use Bazel's cloud features 5============================== 6One of Bazel's defining features is that it's a cloud build system. Team 7members can easily `share artifacts 8<https://app.buildbuddy.io/invocation/f8bc4845-a38d-4c62-b939-14238168ba46>`__ 9(including test logs), builds can be run in parallel on hundreds of machines in 10the cloud, and build artifacts that were built once (by anyone) don't need to 11be rebuilt from scratch. 12 13This section gives you a taste of these features of Bazel using `BuildBuddy 14<https://www.buildbuddy.io/>`_. 15 16---------------- 17BuildBuddy setup 18---------------- 19To use cloud features, you need to get set up with some cloud provider. 20 21.. note:: 22 23 Googlers: see additional instructions at `go/pw-sense-googlers 24 <http://go/pw-sense-googlers#buildbuddy-integration>`_. 25 26#. Go to https://app.buildbuddy.io/ and log in via Google or GitHub. 27#. Click `Quickstart Guide <https://app.buildbuddy.io/docs/setup/>`__. 28#. In step 1 (**Configure your .bazelrc**) enable the following options: 29 30 * **API Key** 31 * **Enable cache** 32 * **Full cache** 33 34 .. caution:: 35 36 :bug:`364781685`: Sense does not support remote execution yet, so don't 37 enable that option. 38 39#. Copy the provided snippet to ``//.bazelrc`` (the ``.bazelrc`` file in the root 40 directory of your Sense repository). 41 42 .. figure:: https://storage.googleapis.com/pigweed-media/sense/buildbuddy_bazelrc_v1.png 43 44#. Try :ref:`building the blinky app <showcase-sense-tutorial-build>` again to verify your 45 BuildBuddy integration. While the build runs you should see an information log indicating 46 that the build is streaming to BuildBuddy, like this: 47 48 .. code-block:: text 49 50 INFO: Streaming build results to: https://app.buildbuddy.io/invocation/6d467374-ffad-44be-a6be-e4f7b53129dd 51 52--------------------- 53Review and share logs 54--------------------- 55Let's go back to what we learned in :ref:`showcase-sense-tutorial-hosttests` and run a test. 56 57#. Open ``//modules/blinky/blinky_test.cc``. 58 59#. Make the ``Toggle`` test fail by changing one of the expected values. 60 Example: 61 62 .. code-block:: c++ 63 64 TEST_F(BlinkyTest, Toggle) { 65 // ... 66 auto event = FirstActive(); 67 ASSERT_NE(event, monochrome_led_.events().end()); 68 EXPECT_EQ(event->state, State::kInactive); // add this line 69 // EXPECT_EQ(event->state, State::kActive); // comment out this line 70 EXPECT_GE(ToMs(event->timestamp - start), kIntervalMs * 0); 71 start = event->timestamp; 72 // ... 73 } 74 75 .. caution:: Remember to save your changes! 76 .. tab-set:: 77 78 .. tab-item:: VS Code 79 :sync: vsc 80 81 In **Bazel Build Targets** expand **//modules/blinky**, then right-click 82 **:blinky_test (cc_test)**, then select **Test target**. 83 84 .. figure:: https://storage.googleapis.com/pigweed-media/sense/20240802/test_target_v2.png 85 :alt: Selecting Test target 86 87 Starting ``blinky_test`` 88 89 A task launches a terminal. You should see ``blinky_test`` fail, and a 90 BuildBuddy invocation link printed: 91 92 .. code-block:: console 93 94 //modules/blinky:blinky_test FAILED in 0.4s 95 INFO: Streaming build results to: https://app.buildbuddy.io/invocation/f8bc4845-a38d-4c62-b939-14238168ba46 96 97 .. tab-item:: CLI 98 :sync: cli 99 100 Run the following command. You should see output similar to what's 101 shown after the command. The key line starts with ``INFO: Streaming 102 build results to:``. It contains the BuildBuddy invocation link. 103 104 .. code-block:: console 105 106 $ bazelisk test //modules/blinky:blinky_test 107 # ... 108 //modules/blinky:blinky_test FAILED in 0.4s 109 /home/kayce/.cache/bazel/_bazel_kayce/27fcdd448f61589ce2692618b3237728/execroot/showcase-rp2/bazel-out/k8-fastbuild/testlogs/modules/blinky/blinky_test/test.log 110 111 Executed 1 out of 1 test: 1 fails locally. 112 INFO: Streaming build results to: https://app.buildbuddy.io/invocation/f8bc4845-a38d-4c62-b939-14238168ba46 113 114#. Click the provided BuildBuddy link. Some highlights to notice: 115 116 * The **LOGS** tab provides a full log of the failed test. 117 * The **DETAILS** tab shows the exact command line invocation for reproducing this result. 118 * The **TIMING** tab shows a granular breakdown of how long Bazel took to build and execute the test. 119 120#. Click **Share** (top-right corner) and broaden the permissions to make 121 the invocation link shareable. Then show it off to your friends and 122 coworkers! 123 124-------------- 125Remote caching 126-------------- 127Bazel supports remote caching: if you (or someone else in your organization) 128already built an artifact, you can simply retrieve it from the cache instead of 129building it from scratch. Let's test it out. 130 131 132#. Remove all local Bazel build results. 133 134 .. code-block:: console 135 136 $ bazelisk clean 137 138#. Run ``blinky_test`` again. It should be quite fast, even though you 139 discarded all the build artifacts. Bazel simply downloads them from the 140 remote cache that your previous invocation populated! 141 142 You can click the **CACHE** tab in the BuildBuddy invocation UI to see more 143 details on cache performance: how many hits there were, how much data was 144 uploaded and downloaded, etc. 145 146------- 147Summary 148------- 149In this section, you've gotten a taste of the cloud features of Bazel: 150generating easily shareable URLs for build and test invocations, and speeding 151up your builds by leveraging remote caching. 152 153Next, head over to :ref:`showcase-sense-tutorial-prod` to try 154out the ``production`` app that exercises more of the Enviro+ Pack hardware. 155
