ci: add Trivy security scanning workflow and status badge

- Add a GitHub Actions workflow to perform Trivy security scanning on code pushes, pull requests, scheduled runs, and manual dispatch
- Display Trivy Security Scan status badge in the README

Signed-off-by: appleboy <appleboy.tw@gmail.com>

Author: appleboy

.github/workflows/trivy-scan.yml

@@ -0,0 +1,56 @@
+name: Trivy Security Scan
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+  schedule:
+    # Run daily at 00:00 UTC
+    - cron: '0 0 * * *'
+  workflow_dispatch: # Allow manual trigger
+
+permissions:
+  contents: read
+  security-events: write # Required for uploading SARIF results
+
+jobs:
+  trivy-scan:
+    name: Trivy Security Scan
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+
+      - name: Run Trivy vulnerability scanner (source code)
+        uses: aquasecurity/trivy-action@0.33.1
+        with:
+          scan-type: 'fs'
+          scan-ref: '.'
+          scanners: 'vuln,secret,misconfig'
+          format: 'sarif'
+          output: 'trivy-results.sarif'
+          severity: 'CRITICAL,HIGH,MEDIUM'
+          ignore-unfixed: true
+
+      - name: Upload Trivy results to GitHub Security tab
+        uses: github/codeql-action/upload-sarif@v4
+        if: always()
+        with:
+          sarif_file: 'trivy-results.sarif'
+
+      - name: Run Trivy scanner (table output for logs)
+        uses: aquasecurity/trivy-action@0.33.1
+        if: always()
+        with:
+          scan-type: 'fs'
+          scan-ref: '.'
+          scanners: 'vuln,secret,misconfig'
+          format: 'table'
+          severity: 'CRITICAL,HIGH,MEDIUM'
+          ignore-unfixed: true
+          exit-code: '1'

README.md

@@ -1,6 +1,7 @@
 # expvar
 
 [![Run Tests](https://github.com/gin-contrib/expvar/actions/workflows/go.yml/badge.svg?branch=master)](https://github.com/gin-contrib/expvar/actions/workflows/go.yml)
+[![Trivy Security Scan](https://github.com/gin-contrib/expvar/actions/workflows/trivy-scan.yml/badge.svg)](https://github.com/gin-contrib/expvar/actions/workflows/trivy-scan.yml)
 [![codecov](https://codecov.io/gh/gin-contrib/expvar/branch/master/graph/badge.svg)](https://codecov.io/gh/gin-contrib/expvar)
 [![Go Report Card](https://goreportcard.com/badge/github.com/gin-contrib/expvar)](https://goreportcard.com/report/github.com/gin-contrib/expvar)
 [![GoDoc](https://godoc.org/github.com/gin-contrib/expvar?status.svg)](https://godoc.org/github.com/gin-contrib/expvar)