From 84fe7831ebced2ce84e166dedaa27da026f9cb98 Mon Sep 17 00:00:00 2001
From: Brian Seeders <brian.seeders@elastic.co>
Date: Mon, 16 Dec 2024 11:31:05 -0500
Subject: [PATCH] [CI] Automatically apply spotless changes in pull request CI
 (#118701) (#118711)

(cherry picked from commit f900ae61bbc3ba9670a832206f4a6552013f67c4)
---
 .buildkite/pipelines/pull-request/part-1.yml  |  4 +-
 .../pipelines/pull-request/precommit.yml      |  4 +-
 .buildkite/scripts/spotless.sh                | 44 +++++++++++++++++++
 3 files changed, 50 insertions(+), 2 deletions(-)
 create mode 100755 .buildkite/scripts/spotless.sh

diff --git a/.buildkite/pipelines/pull-request/part-1.yml b/.buildkite/pipelines/pull-request/part-1.yml
index 3d467c6c41e43..7a09e2a162ff8 100644
--- a/.buildkite/pipelines/pull-request/part-1.yml
+++ b/.buildkite/pipelines/pull-request/part-1.yml
@@ -1,6 +1,8 @@
 steps:
   - label: part-1
-    command: .ci/scripts/run-gradle.sh -Dignore.tests.seed checkPart1
+    command: |
+      .buildkite/scripts/spotless.sh # This doesn't have to be part of part-1, it was just a convenient place to put it
+      .ci/scripts/run-gradle.sh -Dignore.tests.seed checkPart1
     timeout_in_minutes: 300
     agents:
       provider: gcp
diff --git a/.buildkite/pipelines/pull-request/precommit.yml b/.buildkite/pipelines/pull-request/precommit.yml
index f6548dfeed9b2..1763758932581 100644
--- a/.buildkite/pipelines/pull-request/precommit.yml
+++ b/.buildkite/pipelines/pull-request/precommit.yml
@@ -3,7 +3,9 @@ config:
   skip-labels: []
 steps:
   - label: precommit
-    command: .ci/scripts/run-gradle.sh -Dignore.tests.seed precommit
+    command: |
+      .buildkite/scripts/spotless.sh
+      .ci/scripts/run-gradle.sh -Dignore.tests.seed precommit
     timeout_in_minutes: 300
     agents:
       provider: gcp
diff --git a/.buildkite/scripts/spotless.sh b/.buildkite/scripts/spotless.sh
new file mode 100755
index 0000000000000..b9e6094edb2c7
--- /dev/null
+++ b/.buildkite/scripts/spotless.sh
@@ -0,0 +1,44 @@
+#!/bin/bash
+
+if [[ -z "${BUILDKITE_PULL_REQUEST:-}" ]]; then
+  echo "Not a pull request, skipping spotless"
+  exit 0
+fi
+
+if ! git diff --exit-code; then
+  echo "Changes are present before running spotless, not running"
+  git status
+  exit 0
+fi
+
+NEW_COMMIT_MESSAGE="[CI] Auto commit changes from spotless"
+PREVIOUS_COMMIT_MESSAGE="$(git log -1 --pretty=%B)"
+
+echo "--- Running spotless"
+.ci/scripts/run-gradle.sh -Dscan.tag.NESTED spotlessApply
+
+if git diff --exit-code; then
+  echo "No changes found after running spotless. Don't need to auto commit."
+  exit 0
+fi
+
+if [[ "$NEW_COMMIT_MESSAGE" == "$PREVIOUS_COMMIT_MESSAGE" ]]; then
+  echo "Changes found after running spotless"
+  echo "CI already attempted to commit these changes, but the file(s) seem to have changed again."
+  echo "Please review and fix manually."
+  exit 1
+fi
+
+git config --global user.name elasticsearchmachine
+git config --global user.email 'infra-root+elasticsearchmachine@elastic.co'
+
+gh pr checkout "${BUILDKITE_PULL_REQUEST}"
+git add -u .
+git commit -m "$NEW_COMMIT_MESSAGE"
+git push
+
+# After the git push, the new commit will trigger a new build within a few seconds and this build should get cancelled
+# So, let's just sleep to give the build time to cancel itself without an error
+# If it doesn't get cancelled for some reason, then exit with an error, because we don't want this build to be green (we just don't want it to generate an error either)
+sleep 300
+exit 1