Add config to build impacted frontends

config/jobs/presubmits.yaml

@@ -50,6 +50,24 @@ presubmits:
             command:
               - hack/non_manual_build.sh
 
+    - name: pull-peridot-build-impacted-frontend
+      branches:
+        - main
+      always_run: true
+      decorate: true
+      spec:
+        tolerations:
+          - key: peridot.rockylinux.org/workflow-tolerates-arch
+            operator: Equal
+            value: amd64
+            effect: NoSchedule
+        nodeSelector:
+          peridot.rockylinux.org/workflow-tolerates-arch: amd64
+        containers:
+          - image: quay.io/peridot/ci:v0.3.16
+            command:
+              - hack/frontend_build.sh
+
     - name: pull-peridot-gofmt-check
       branches:
         - main

hack/build_impacted_frontend.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+
+set -o errexit
+
+source hack/bazel_setup.sh
+
+starting_query="attr(tags, 'resf_frontend_bundle',"
+
+for t in `cat impacted_targets`; do
+  starting_query="$starting_query $t union"
+done
+
+starting_query=${starting_query%" union"}
+starting_query="$starting_query)"
+
+$BAZEL_B $($BAZEL_QR "$starting_query")

hack/frontend_build.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+
+set -o errexit
+
+source hack/bazel_setup.sh
+
+bazel_bin="$(which bazel)"
+workspace_dir="$(pwd)"
+
+$BAZEL_B //:bazel-diff
+
+# Generate starting hashes
+git checkout "$PULL_BASE_SHA" --quiet
+bazel-bin/bazel-diff generate-hashes -w "$workspace_dir" -b "$bazel_bin" starting_hashes_json
+
+# Generate ending hashes
+git checkout "$PULL_PULL_SHA" --quiet
+bazel-bin/bazel-diff generate-hashes -w "$workspace_dir" -b "$bazel_bin" ending_hashes_json
+
+# Get impacted targets
+bazel-bin/bazel-diff get-impacted-targets -sh starting_hashes_json -fh ending_hashes_json impacted_targets
+
+# Build impacted targets
+hack/build_impacted_frontend.sh
+
+