Add nativelink remote execution to github actions

* Create github action that generates .buckconfig.local
  using `NATIVELINK_HEADER_RW_KEY` from gha secrets.
* Set `container-image` used for remote execution specific
  to setup of buck2.
* Update .gitignore to include .buckconfig.local.

Author: Adam Singer

.github/actions/build_example_nativelink/action.yml

@@ -0,0 +1,25 @@
+name: build_example_nativelink
+inputs:
+  NATIVELINK_HEADER_RW_KEY_SECRET:
+    description: ''
+    required: true
+runs:
+  using: composite
+  steps:
+  - name: Build examples/remote_execution/nativelink directory using remote execution
+    run: |-
+      cat <<EOL > examples/remote_execution/nativelink/.buckconfig.local
+      [buck2_re_client]
+      engine_address       = grpc://scheduler-buck2.build-faster.nativelink.net:443
+      action_cache_address = grpc://cas-buck2.build-faster.nativelink.net:443
+      cas_address          = grpc://cas-buck2.build-faster.nativelink.net:443
+      http_headers         = x-nativelink-api-key:${NATIVELINK_HEADER_RW_KEY}
+      tls = true
+      instance_name = main
+      EOL
+
+      cd examples/remote_execution/nativelink
+      $RUNNER_TEMP/artifacts/buck2 build //... -v 4
+    env:
+      NATIVELINK_HEADER_RW_KEY: ${{ inputs.NATIVELINK_HEADER_RW_KEY_SECRET }}
+    shell: bash

.github/workflows/build-and-test.yml

@@ -69,6 +69,9 @@ jobs:
         $RUNNER_TEMP/artifacts/buck2 test //... -v 2
     - uses: ./.github/actions/build_example_conan
     - uses: ./.github/actions/build_example_no_prelude
+    - uses: ./.github/actions/build_example_nativelink
+      with:
+        NATIVELINK_HEADER_RW_KEY_SECRET: ${{ secrets.NATIVELINK_HEADER_RW_KEY_SECRET }}
     - uses: ./.github/actions/setup_reindeer
     - uses: ./.github/actions/build_bootstrap
   windows-build-examples:

examples/remote_execution/nativelink/platforms/defs.bzl

@@ -21,7 +21,7 @@ def _platforms(ctx):
             # Set those up based on what workers you've registered with NativeLink.
             remote_execution_properties = {
                 "OSFamily": "linux",
-                "container-image": "docker://ghcr.io/catthehacker/ubuntu:act-22.04@sha256:5f9c35c25db1d51a8ddaae5c0ba8d3c163c5e9a4a6cc97acd409ac7eae239448",
+                "container-image": "docker://buck2-github:latest",
             },
             remote_execution_use_case = "buck2-default",
             remote_output_paths = "output_paths",