add trivy

.github/workflows/trivy.yaml

@@ -0,0 +1,30 @@
+name:  Run Trivy scan
+
+on:
+  push:
+    tags:
+      - '*'
+    branches:
+      - "gha-*" # for testing
+  pull_request:
+
+
+jobs:
+  trivy:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - name: Checkout Repo
+        uses: actions/checkout@v4
+      - name: Get base image
+        run: |
+          image=$(grep hyperkube-base Dockerfile | awk '{ print $2 }')
+          echo "HYPERKUBE=${image}"
+          echo "HYPERKUBE=${image}" >> "$GITHUB_ENV"
+      - name: Run Trivy scanner
+        uses: aquasecurity/trivy-action@d710430a6722f083d3b36b8339ff66b32f22ee55 # v0.19.0
+        with:
+          image-ref:  ${{ env.HYPERKUBE }}
+          exit-code: '1'
+          severity: 'CRITICAL,HIGH'