Add OpenSSF Scorecard workflow and README badge (#10467)

Velero has no published OpenSSF Scorecard results, so the Scorecard
badge does not resolve and CLOMonitor flags the openssf_scorecard_badge
check as missing.

Add the ossf/scorecard-action workflow (SHA-pinned, least-privilege
permissions, publish_results enabled) running weekly and on push to
main. Once it runs post-merge, results publish to the OpenSSF API and
the README badge resolves. This also surfaces the project's security
posture (currently 6.2/10) to guide further hardening.

Part of the CNCF incubation readiness work (#10383).

Signed-off-by: Shubham Pampattiwar <spampatt@redhat.com>

.github/workflows/scorecard.yml

@@ -0,0 +1,56 @@
+name: Scorecard supply-chain security
+on:
+  # For Branch-Protection check. Only the default branch is supported. See
+  # https://github.com/ossf/scorecard/blob/main/docs/checks.md#branch-protection
+  branch_protection_rule:
+  # To guarantee Maintained check is occasionally updated. See
+  # https://github.com/ossf/scorecard/blob/main/docs/checks.md#maintained
+  schedule:
+    - cron: '20 7 * * 1'
+  push:
+    branches: [ "main" ]
+
+# Declare default permissions as read only.
+permissions: read-all
+
+jobs:
+  analysis:
+    name: Scorecard analysis
+    runs-on: ubuntu-latest
+    # Skip on forks; results are only meaningful for the canonical repo.
+    if: github.repository == 'velero-io/velero'
+    permissions:
+      # Needed to upload the results to code-scanning dashboard.
+      security-events: write
+      # Needed to publish results and get a badge (see publish_results below).
+      id-token: write
+
+    steps:
+      - name: "Checkout code"
+        uses: actions/checkout@v7
+        with:
+          persist-credentials: false
+
+      - name: "Run analysis"
+        uses: ossf/scorecard-action@2d1146689b8cda280b9bc96326124645441f03bc # v2.4.4
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          # Publish results to OpenSSF REST API for the Scorecard badge and to
+          # allow the project to be included in the OpenSSF metrics dashboard.
+          publish_results: true
+
+      # Upload the results as artifacts (optional). Commenting out will disable
+      # uploads of run results in SARIF format to the repository Actions tab.
+      - name: "Upload artifact"
+        uses: actions/upload-artifact@v7
+        with:
+          name: SARIF file
+          path: results.sarif
+          retention-days: 5
+
+      # Upload the results to GitHub's code scanning dashboard.
+      - name: "Upload to code-scanning"
+        uses: github/codeql-action/upload-sarif@v4.37.9
+        with:
+          sarif_file: results.sarif

README.md

@@ -1,6 +1,7 @@
 ![100]
 
 [![Build Status][1]][2] [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/3811/badge)](https://bestpractices.coreinfrastructure.org/projects/3811)
+[![OpenSSF Scorecard](https://api.scorecard.dev/projects/github.com/velero-io/velero/badge)](https://scorecard.dev/viewer/?uri=github.com/velero-io/velero)
 [![GitHub release (latest SemVer)](https://img.shields.io/github/v/release/velero-io/velero)](https://github.com/velero-io/velero/releases)
 [![GitHub stars](https://img.shields.io/github/stars/velero-io/velero)](https://github.com/velero-io/velero/stargazers)
 [![Docker Pulls](https://img.shields.io/docker/pulls/velero/velero.svg)](https://hub.docker.com/r/velero/velero)