feat(raycilint): add GitHub Action workflow for PR size checks

Adds a GitHub Actions workflow that runs rayci-lint prsize on pull requests and posts a sticky comment when thresholds are exceeded. The job fails unless the PR has a configurable skip label (default: skip-prcheck).

Topic: prcheck-action
Relative: prcheck-binary
Signed-off-by: andrew <andrew@anyscale.com>

Author: andrew-anyscale

.buildkite/raycilint.yaml

@@ -2,3 +2,6 @@ go_filelength:
   max_lines: 500
 go_coverage:
   min_coverage_pct: 80
+prsize:
+  max_additions: 500
+  max_deletions: 2000

.github/workflows/prcheck.yaml

@@ -0,0 +1,70 @@
+name: PR Check
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened, labeled, unlabeled]
+
+permissions:
+  pull-requests: write
+
+env:
+  CONFIG_PATH: ".buildkite/raycilint.yaml"
+  SKIP_LABEL: "skip-prcheck" # If updating this label, also update harcoded ref below.
+
+jobs:
+  check:
+    name: PR size check
+    # Skip all label-related events unless the skip-prcheck label was toggled.
+    # env context is unavailable in job-level if, so the label name must be hardcoded.
+    if: >-
+      (github.event.action != 'labeled' && github.event.action != 'unlabeled')
+      || github.event.label.name == 'skip-prcheck'
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - name: Check for skip label
+        id: check
+        if: ${{ !contains(github.event.pull_request.labels.*.name, env.SKIP_LABEL) }}
+        run: echo "run=true" >> "$GITHUB_OUTPUT"
+
+      - uses: actions/checkout@v4
+        if: steps.check.outputs.run
+        with:
+          fetch-depth: 1
+          persist-credentials: false
+
+      - uses: actions/setup-go@v5
+        if: steps.check.outputs.run
+        with:
+          go-version-file: go.mod
+
+      - name: Run prcheck
+        id: prcheck
+        if: steps.check.outputs.run
+        env:
+          BASE_REF: ${{ github.event.pull_request.base.ref }}
+          HEAD_REF: ${{ github.event.pull_request.head.ref }}
+        run: >-
+          go run ./raycilint/raycilint -config-file "$CONFIG_PATH" prsize
+          -base-ref "$BASE_REF"
+          -head-ref "$HEAD_REF"
+
+      - name: Update size warning comment
+        if: failure()
+        uses: marocchino/sticky-pull-request-comment@773744901bac0e8cbb5a0dc842800d45e9b2b405 # v2
+        with:
+          header: prcheck
+          message: |
+            ## ⚠️ PR Size Warning
+            This PR exceeds the size limits defined in `${{ env.CONFIG_PATH }}`.
+            ${{ steps.prcheck.outputs.additions && format('- additions: `{0}`', steps.prcheck.outputs.additions) || '' }}
+            ${{ steps.prcheck.outputs.deletions && format('- deletions: `{0}`', steps.prcheck.outputs.deletions) || '' }}
+
+            Break this into smaller PRs, or apply the `${{ env.SKIP_LABEL }}` label to bypass.
+
+      - name: Delete size warning comment
+        if: success() || !steps.check.outputs.run
+        uses: marocchino/sticky-pull-request-comment@773744901bac0e8cbb5a0dc842800d45e9b2b405 # v2
+        with:
+          header: prcheck
+          delete: true

run_prcheck.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+
+set -euo pipefail
+
+TMP_DIR="$(mktemp -d)"
+
+if [[ -f .rayciversion ]]; then
+  RAYCI_VERSION="$(cat .rayciversion)"
+  echo "--- Install rayci-lint binary ${RAYCI_VERSION}"
+  curl -sfL "https://github.com/ray-project/rayci/releases/download/v${RAYCI_VERSION}/rayci-lint-linux-amd64" -o "$TMP_DIR/rayci-lint"
+  chmod +x "$TMP_DIR/rayci-lint"
+  exec "$TMP_DIR/rayci-lint" prsize "$@"
+
+  exit 1  # Unreachable; just for safe-guarding.
+fi
+
+# Legacy path; build from source.
+
+RAYCI_BRANCH="${RAYCI_BRANCH:-stable}"
+
+echo "--- Install rayci-lint"
+
+readonly GO_VERSION=1.24.5
+curl -sfL "https://go.dev/dl/go${GO_VERSION}.linux-amd64.tar.gz" | tar -xzf - -C "$TMP_DIR"
+export GOROOT="$TMP_DIR/go"
+export GOPATH="$TMP_DIR/gopath"
+export GOPRIVATE="github.com/ray-project/rayci"
+"$TMP_DIR/go/bin/go" install 'github.com/ray-project/rayci/raycilint/raycilint@'"${RAYCI_BRANCH}"
+
+echo "--- Run rayci-lint prsize"
+
+exec "$GOPATH/bin/raycilint" prsize "$@"