[feat][ci] Add Trivy container scan Github workflow

This commit introduces a Github Actions workflow that runs a Trivy
container scan on the following Docker containers:

- apachepulsar/pulsar:3.2.0
- apachepulsar/pulsar-all:3.2.0

The workflow runs daily @ 0800 UTC and if it finds any vulnerabilities
of HIGH or CRITICAL severity it sends an email including the report
to the Pulsar DEV mailing list as well as upload the report to the
workflow run in Github.

.github/workflows/ci-trivy-container-scan.yaml

@@ -0,0 +1,92 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+name: CI - Trivy Container Scan
+on:
+  schedule:
+    - cron: '0 8 * * *' # Every day at 8am UTC
+  workflow_dispatch:
+    inputs:
+      report-format:
+        description: 'Format of the report'
+        type: choice
+        default: table
+        options:
+          - table
+          - json
+          - sarif
+      severity:
+        description: "Severities to include (comma-separated or 'ALL' to include all)"
+        required: false
+        default: 'CRITICAL,HIGH'
+
+jobs:
+  container_scan:
+    if: ${{ github.repository == 'apache/pulsar' }}
+    name: Trivy Docker image vulnerability scan
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        docker-image:
+          - 'apachepulsar/pulsar'
+          - 'apachepulsar/pulsar-all'
+        docker-tag:
+          - '3.2.0'
+    env:
+      IMAGE_REF: '${{ matrix.docker-image }}:${{ matrix.docker-tag }}'
+    steps:
+      - id: prepare-vars
+        shell: bash
+        run: |
+          IMAGE_REF_CLEAN="$(echo $IMAGE_REF | sed 's/-/_/g; s/\./_/g; s/:/_/g; s/\//_/g')"
+          echo "image_ref_clean=$IMAGE_REF_CLEAN" >> "$GITHUB_OUTPUT"
+          echo "report_filename=trivy-scan-$IMAGE_REF_CLEAN.${{ inputs.report-format }}" >> "$GITHUB_OUTPUT"
+      - name: Run Trivy container scan
+        uses: aquasecurity/trivy-action@master
+        with:
+          image-ref: ${{ env.IMAGE_REF }}
+          scanners: vuln
+          severity: ${{ inputs.severity != 'ALL' && inputs.severity ||  'UNKNOWN,LOW,MEDIUM,HIGH,CRITICAL'  }}
+          limit-severities-for-sarif: true
+          format: ${{ inputs.report-format }}
+          output: ${{ steps.prepare-vars.outputs.report_filename }}
+          exit-code: 1
+      - name: Email Trivy container scan report
+        uses: dawidd6/action-send-mail@v3
+        if: ${{ failure() }}
+        with:
+          server_address: smtp.gmail.com
+          server_port: 465
+          secure: true
+          username: ${{secrets.TRIVY_SCAN_MAIL_USERNAME}}
+          password: ${{secrets.TRIVY_SCAN_MAIL_PASSWORD}}
+          subject: Trivy container scan results for ${{ env.IMAGE_REF }}
+          to: [email protected]
+          from: Github Trivy Container Scanner
+          body: Trivy reported vulnerabilities (${{ inputs.severity }}) for ${{ env.IMAGE_REF }}
+          ignore_cert: true
+          attachments: '${{ github.workspace }}/${{ steps.prepare-vars.outputs.report_filename }}'
+      - name: Upload Trivy container scan report
+        uses: actions/upload-artifact@v4
+        if: ${{ failure() }}
+        with:
+          name: trivy-vuln-report-${{ steps.prepare-vars.outputs.image_ref_clean }}
+          path: '${{ github.workspace }}/${{ steps.prepare-vars.outputs.report_filename }}'
+          retention-days: 15