From 6095cf897df69ad5236064bee05b9f9766152f1c Mon Sep 17 00:00:00 2001
From: Bharath B <bhb@redhat.com>
Date: Wed, 14 Aug 2024 21:09:45 +0530
Subject: [PATCH] NE-1803: Reload router when defaultDestinationCA is updated

---
 pkg/router/router_test.go     | 18 ++++++++++++------
 pkg/router/template/router.go | 28 ++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/pkg/router/router_test.go b/pkg/router/router_test.go
index 1b747224e..2a8c3cda6 100644
--- a/pkg/router/router_test.go
+++ b/pkg/router/router_test.go
@@ -102,11 +102,16 @@ func TestMain(m *testing.M) {
 
 	h.workdir = workdir
 	h.dirs = map[string]string{
-		"whitelist": filepath.Join(workdir, "router", "whitelists"),
-		"certs":     filepath.Join(workdir, "router", "certs"),
+		"whitelist":     filepath.Join(workdir, "router", "whitelists"),
+		"certs":         filepath.Join(workdir, "router", "certs"),
+		"serviceCA":     filepath.Join(workdir, "service-ca"),
+		"serviceCAData": filepath.Join(workdir, "service-ca", "..data/"),
 	}
 
 	createRouterDirs()
+	defaultDestinationCA := filepath.Join(h.dirs["serviceCA"], "service-ca.crt")
+	os.Create(filepath.Join(h.dirs["serviceCAData"], "service-ca.crt"))
+	os.Symlink(filepath.Join(h.dirs["serviceCAData"], "service-ca.crt"), defaultDestinationCA)
 
 	// The template plugin which is wrapped
 	svcFetcher := templateplugin.NewListWatchServiceLookup(client.CoreV1(), 60*time.Second, namespace)
@@ -147,10 +152,11 @@ pgfj+yGLmkUw8JwgGH6xCUbHO+WBUFSlPf+Y50fJeO+OrjqPXAVKeSV3ZCwWjKT4
 u3YLAbyW/lHhOCiZu2iAI8AbmXem9lW6Tr7p/97s0w==
 -----END RSA PRIVATE KEY-----
 `,
-		DefaultCertificateDir: h.dirs["certs"],
-		ReloadFn:              func(shutdown bool) error { return nil },
-		TemplatePath:          "../../images/router/haproxy/conf/haproxy-config.template",
-		ReloadInterval:        reloadInterval,
+		DefaultCertificateDir:    h.dirs["certs"],
+		DefaultDestinationCAPath: defaultDestinationCA,
+		ReloadFn:                 func(shutdown bool) error { return nil },
+		TemplatePath:             "../../images/router/haproxy/conf/haproxy-config.template",
+		ReloadInterval:           reloadInterval,
 		HTTPResponseHeaders: []templateplugin.HTTPHeader{{
 			Name:   "x-foo",
 			Value:  "'bar'",
diff --git a/pkg/router/template/router.go b/pkg/router/template/router.go
index 17ccccb9f..060742f8c 100644
--- a/pkg/router/template/router.go
+++ b/pkg/router/template/router.go
@@ -289,6 +289,9 @@ func newTemplateRouter(cfg templateRouterCfg) (*templateRouter, error) {
 	if err := router.watchMutualTLSCert(); err != nil {
 		return nil, err
 	}
+	if err := router.watchCABundleCert(); err != nil {
+		return nil, err
+	}
 	if router.dynamicConfigManager != nil {
 		log.V(0).Info("initializing dynamic config manager ... ")
 		router.dynamicConfigManager.Initialize(router, router.defaultCertificatePath)
@@ -1521,3 +1524,28 @@ func privateKeysFromPEM(pemCerts []byte) ([]byte, error) {
 	}
 	return buf.Bytes(), nil
 }
+
+// watchCABundleCert watches the directory containing the CA bundle certificate
+// and reloads the router if the directory contents change.
+func (r *templateRouter) watchCABundleCert() error {
+	if len(r.defaultDestinationCAPath) == 0 {
+		log.V(0).Info("defaultDestinationCAPath is empty, file watcher not created")
+		return nil
+	}
+
+	caBundleDir := filepath.Dir(r.defaultDestinationCAPath)
+	reloadFn := func() {
+		log.V(0).Info("reloading to get updated default destination CA certificate bundle")
+		r.rateLimitedCommitFunction.RegisterChange()
+	}
+
+	if err := r.watchVolumeMountDir(caBundleDir, reloadFn); err != nil {
+		// On encountering an error will log it and not return the error because
+		// DefaultDestinationCAPath is an optional configuration parameter, and an
+		// error here shouldn't cause router to exit.
+		log.V(0).Error(err, "failed to establish watch on CA bundle certificate directory")
+		return nil
+	}
+
+	return nil
+}