auto version update improvements

.github/workflows/update_versions.yaml

@@ -1,6 +1,8 @@
 name: Update Versions PR
 
 on:
+  schedule:
+    - cron: "0 0 * * *"
   workflow_dispatch: {}
 
 permissions:
@@ -12,24 +14,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
-      - name: Fetch versions
+      - name: Mirror versions
+        id: mirror-versions
         run: |-
-          bazel run //scripts:mirror_terraform_releases > terraform/private/versions_new.bzl
-
-      - name: Commit and push update
-        run: |-
-          mv terraform/private/versions_new.bzl terraform/private/versions.bzl
           git config --global user.name "GitHub Actions"
           git config --global user.email "[email protected]"
-          git checkout -b update-terraform-versions
-          git add terraform/private/versions.bzl
-          git commit -m "Updated Terraform Versions"
-          git push origin -u update-terraform-versions
+          bazel run //scripts:mirror_terraform_releases
 
       - name: Create PR
+        if: steps.mirror-versions.outputs.has_changes
         run: >-
-          gh pr create --base main --title 'Update Terraform Versions' --body 'Created by Github action'
+          gh pr create --base main --fill
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

scripts/mirror_terraform_releases.sh

@@ -3,6 +3,8 @@
 # replace the `./terraform/private/versions.bzl` file.
 set -Eeuo pipefail
 
+VERSIONS_FILE="$(git rev-parse --show-toplevel)/terraform/private/versions.bzl"
+
 # https://www.hashicorp.com/.well-known/pgp-key.txt
 hashicorp_pgp_key_file="$1"
 
@@ -68,11 +70,31 @@ for terraform_release_url in "${terraform_release_url_dirs[@]}"; do
 
 done
 
-cat <<EOF
+cat <<EOF > "$VERSIONS_FILE"
 """
 GENERATED by \`bazel run //scripts/mirror_terraform_releases\`
 Mirror of Terraform Release info.
 """
 
 TERRAFORM_VERSIONS = $json
 EOF
+
+>&2 echo "Wrote $VERSIONS_FILE"
+
+
+if [ -z "$(git status --porcelain "$VERSIONS_FILE")" ]; then
+    >&2 echo "No new version information generated, exiting"
+    exit 0
+fi
+
+date="$(date --utc -I)"
+
+>&2 echo "New version information generated, committing"
+git checkout -b "auto-update-versions-$date"
+git add "$VERSIONS_FILE"
+git commit -m "Auto updated Terraform versions $date"
+git push origin -u "auto-update-versions-$date"
+
+if [ -n "${GITHUB_OUTPUT:-}" ]; then
+    echo "has_changes=true" >> "$GITHUB_OUTPUT"
+fi