Automate checking for Pyxis schema updates

.github/workflows/schema-update.yaml

@@ -0,0 +1,65 @@
+name: Check for schema updates
+
+on: workflow_dispatch
+
+jobs:
+  update:
+    name: Update generated schema and code for Pyxis
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check for existing pull request
+        id: check_pr
+        run: |
+          pr_count=$(gh pr list --repo "${GITHUB_REPOSITORY}" \
+                                --state open \
+                                --json number,url,title \
+                                --label schema-update \
+                                --jq '. | length')
+          echo "Found ${pr_count} pull request(s) currently open for schema update."
+          echo "pr_count=${pr_count}" | tee -a "${GITHUB_OUTPUT}"
+        env:
+          GH_TOKEN: ${{ github.token }}
+
+      - uses: actions/checkout@v4
+        if: ${{ steps.check_pr.outputs.pr_count == '0' }}
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        if: ${{ steps.check_pr.outputs.pr_count == '0' }}
+        with:
+          go-version-file: go.mod
+
+      - name: Generate changes
+        if: ${{ steps.check_pr.outputs.pr_count == '0' }}
+        run: |
+          # Collect the exit code, but a diff here should not be fatal
+          set +e
+          make ci.generate
+          rc=$?
+          set -e
+
+          if [ "${rc}" != "0" ]; then
+            # 41898282 is the user id of the GitHub Actions bot.
+            # https://github.com/actions/checkout#push-a-commit-using-the-built-in-token
+            git config user.name "github-actions[bot]"
+            git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+
+            timestamp=$(date +%s)
+            git checkout -b "pyxis-schema-update-${timestamp}"
+            git add internal/genpyxis/schema.graphql internal/genpyxis/generated.go
+            git commit -m "Update generated schema and code for Pyxis"
+            git push -u origin "pyxis-schema-update-${timestamp}"
+
+            gh pr create --repo "${GITHUB_REPOSITORY}" \
+                         --title "Update generated schema and code for Pyxis" \
+                         --body "${PR_BODY}" \
+                         --base "${BASE_BRANCH}" \
+                         --head "pyxis-schema-update-${timestamp}"
+          else
+            echo "Schema and code generation completed. No changes were detected."
+          fi
+        env:
+          GH_TOKEN: ${{ github.token }}
+          BASE_BRANCH: ${{ github.ref_name }}
+          PR_BODY: |
+            This pull request was automatically generated by [GitHub Actions](${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}).

Makefile

@@ -89,6 +89,10 @@ diff-check:
 ci.fmt: fmt diff-check
 	echo "=> ci.fmt done"
 
+.PHONY: ci.generate
+ci.generate: generate diff-check
+	echo "=> ci.generate done"
+
 .PHONY: ci.tidy
 ci.tidy: tidy diff-check
 	echo "=> ci.tidy done"