Disable default modsecurity_rules_file if modsecurity-snippet is specified

internal/ingress/controller/template/template.go

@@ -1537,7 +1537,7 @@ func buildModSecurityForLocation(cfg config.Configuration, location *ingress.Loc
 `, location.ModSecurity.TransactionID))
 	}
 
-	if !isMSEnabled {
+	if !isMSEnabled && location.ModSecurity.Snippet == "" {
 		buffer.WriteString(`modsecurity_rules_file /etc/nginx/modsecurity/modsecurity.conf;
 `)
 	}

internal/ingress/controller/template/template_test.go

@@ -1781,8 +1781,8 @@ func TestModSecurityForLocation(t *testing.T) {
 		{"configmap enabled, configmap OWASP enabled, annotation enabled, OWASP disabled", true, true, true, true, false, "", "", ""},
 		{"configmap disabled, annotation enabled, OWASP disabled", false, false, true, true, false, "", "", fmt.Sprintf("%v%v", loadModule, modSecCfg)},
 		{"configmap disabled, annotation disabled, OWASP disabled", false, false, false, true, false, "", "", ""},
-		{"configmap disabled, annotation enabled, OWASP disabled", false, false, true, true, false, testRule, "", fmt.Sprintf("%v%v%v", loadModule, modsecRule, modSecCfg)},
-		{"configmap disabled, annotation enabled, OWASP enabled", false, false, true, true, false, testRule, "", fmt.Sprintf("%v%v%v", loadModule, modsecRule, modSecCfg)},
+		{"configmap disabled, annotation enabled, OWASP disabled", false, false, true, true, false, testRule, "", fmt.Sprintf("%v%v", loadModule, modsecRule)},
+		{"configmap disabled, annotation enabled, OWASP enabled", false, false, true, true, false, testRule, "", fmt.Sprintf("%v%v", loadModule, modsecRule)},
 	}
 
 	for _, testCase := range testCases {

rootfs/etc/nginx/template/nginx.tmpl

@@ -153,10 +153,10 @@ http {
     modsecurity_rules '
       {{ $all.Cfg.ModsecuritySnippet }}
     ';
-    {{ end }}
-
+    {{ else }}
     modsecurity_rules_file /etc/nginx/modsecurity/modsecurity.conf;
-
+    {{ end }}
+
     {{ if $all.Cfg.EnableOWASPCoreRules }}
     modsecurity_rules_file /etc/nginx/owasp-modsecurity-crs/nginx-modsecurity.conf;
     {{ end }}

test/e2e/annotations/modsecurity/modsecurity.go

@@ -342,4 +342,41 @@ var _ = framework.DescribeAnnotation("modsecurity owasp", func() {
 			Expect().
 			Status(http.StatusOK)
 	})
+
+	ginkgo.It("should disable default modsecurity conf setting when modsecurity-snippet is specified", func() {
+		host := "modsecurity.foo.com"
+		nameSpace := f.Namespace
+
+		snippet := `SecRuleEngine On
+		SecRequestBodyAccess On
+		SecAuditEngine RelevantOnly
+		SecAuditLogParts ABIJDEFHZ
+		SecAuditLogType Concurrent
+		SecAuditLog /var/tmp/modsec_audit.log
+		SecAuditLogStorageDir /var/tmp/
+		SecRule REQUEST_HEADERS:User-Agent \"block-ua\" \"log,deny,id:107,status:403,msg:\'UA blocked\'\"`
+
+		annotations := map[string]string{
+			"nginx.ingress.kubernetes.io/enable-modsecurity":  "true",
+			"nginx.ingress.kubernetes.io/modsecurity-snippet": snippet,
+		}
+		f.UpdateNginxConfigMapData("annotation-value-word-blocklist", "load_module, lua_package, _by_lua, location, root, {, }")
+		// Sleep a while just to guarantee that the configmap is applied
+		framework.Sleep()
+		ing := framework.NewSingleIngress(host, "/", host, nameSpace, framework.EchoService, 80, annotations)
+		f.EnsureIngress(ing)
+
+		f.WaitForNginxServer(host,
+			func(server string) bool {
+				return !strings.Contains(server, "modsecurity_rules_file /etc/nginx/modsecurity/modsecurity.conf;") &&
+					strings.Contains(server, "SecAuditLog /var/tmp/modsec_audit.log")
+			})
+
+		f.HTTPTestClient().
+			GET("/").
+			WithHeader("Host", host).
+			WithHeader("User-Agent", "block-ua").
+			Expect().
+			Status(http.StatusForbidden)
+	})
 })