Enable configuration of plugins using configmap

docs/user-guide/nginx-configuration/configmap.md

@@ -74,6 +74,7 @@ The following table shows a configuration option's name, type, and the default v
 |[server-name-hash-bucket-size](#server-name-hash-bucket-size)|int|`<size of the processor’s cache line>`
 |[proxy-headers-hash-max-size](#proxy-headers-hash-max-size)|int|512|
 |[proxy-headers-hash-bucket-size](#proxy-headers-hash-bucket-size)|int|64|
+|[plugins](#plugins)|[]string| |
 |[reuse-port](#reuse-port)|bool|"true"|
 |[server-tokens](#server-tokens)|bool|"true"|
 |[ssl-ciphers](#ssl-ciphers)|string|"ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256"|
@@ -465,6 +466,11 @@ _References:_
 - [http://nginx.org/en/docs/hash.html](http://nginx.org/en/docs/hash.html)
 - [https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_headers_hash_bucket_size](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_headers_hash_bucket_size)
 
+## plugins
+
+Configures plugins to use placed in the directory /etc/nginx/lua/plugins. Every plugin has to have main.lua in the root.
+Every plugin has to bundle all of its dependencies. The execution order follows the definition.
+
 ## server-tokens
 
 Send NGINX Server header in responses and display NGINX version in error pages. _**default:**_ is enabled

internal/ingress/controller/config/config.go

@@ -268,6 +268,11 @@ type Configuration struct {
 	NginxStatusIpv4Whitelist []string `json:"nginx-status-ipv4-whitelist,omitempty"`
 	NginxStatusIpv6Whitelist []string `json:"nginx-status-ipv6-whitelist,omitempty"`
 
+	// Plugins configures plugins to use placed in the directory /etc/nginx/lua/plugins.
+	// Every plugin has to have main.lua in the root. Every plugin has to bundle all of its dependencies.
+	// The execution order follows the definition.
+	Plugins []string `json:"plugins,omitempty"`
+
 	// If UseProxyProtocol is enabled ProxyRealIPCIDR defines the default the IP/network address
 	// of your external load balancer
 	ProxyRealIPCIDR []string `json:"proxy-real-ip-cidr,omitempty"`

internal/ingress/controller/template/configmap.go

@@ -61,6 +61,7 @@ const (
 	globalAuthCacheKey        = "global-auth-cache-key"
 	globalAuthCacheDuration   = "global-auth-cache-duration"
 	luaSharedDictsKey         = "lua-shared-dicts"
+	plugins                   = "plugins"
 )
 
 var (
@@ -341,6 +342,15 @@ func ReadConfig(src map[string]string) config.Configuration {
 		delete(conf, workerProcesses)
 	}
 
+	if val, ok := conf[plugins]; ok {
+		to.Plugins = strings.Split(val, ",")
+		for i := range to.Plugins {
+			to.Plugins[i] = strings.TrimSpace(to.Plugins[i])
+		}
+
+		delete(conf, plugins)
+	}
+
 	to.CustomHTTPErrors = filterErrors(errors)
 	to.SkipAccessLogURLs = skipUrls
 	to.WhitelistSourceRange = whiteList

rootfs/etc/nginx/template/nginx.tmpl

@@ -103,7 +103,7 @@ http {
           plugins = res
         end
         -- load all plugins that'll be used here
-        plugins.init({})
+        plugins.init({ {{ range  $idx, $plugin := $cfg.Plugins }}{{ if $idx }},{{ end }}{{ $plugin | quote }}{{ end }} })
     }
 
     init_worker_by_lua_block {

test/e2e/settings/plugins.go

@@ -0,0 +1,54 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed 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.
+*/
+
+package settings
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/onsi/ginkgo"
+	"k8s.io/ingress-nginx/test/e2e/framework"
+)
+
+var _ = framework.IngressNginxDescribe("plugins", func() {
+	f := framework.NewDefaultFramework("plugins")
+
+	ginkgo.BeforeEach(func() {
+		f.NewEchoDeployment()
+	})
+
+	ginkgo.It("should exist a x-hello-world header", func() {
+		f.UpdateNginxConfigMapData("plugins", "hello_world, invalid")
+
+		host := "example.com"
+		f.EnsureIngress(framework.NewSingleIngress(host, "/", host, f.Namespace, framework.EchoService, 80, nil))
+
+		f.WaitForNginxConfiguration(
+			func(server string) bool {
+				return strings.Contains(server, fmt.Sprintf("server_name %v", host)) &&
+					strings.Contains(server, `plugins.init({ "hello_world","invalid" })`)
+			})
+
+		f.HTTPTestClient().
+			GET("/").
+			WithHeader("Host", host).
+			Expect().
+			Status(http.StatusOK).
+			Body().Contains("x-hello-world=1")
+	})
+})