Support none keyword in log-format escape (#8692)

* Support none keyword in log-format escape


## What this PR does / why we need it:
ingress-nginx does not support disabling escaping of special characters in the nginx log. This PR exposes the setting to support that functionality.

## Types of changes
- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to change)
- [ ] Documentation only

## Which issue/s this PR fixes
<!--
(optional, in `fixes #<issue number>` format, will close that issue when PR gets merged):

fixes #
-->

## How Has This Been Tested?
Followed the [getting-started](96b6228a6b/docs/developer-guide/getting-started.md) guide. Used ppa:longsleep/golang-backports on WSL Ubuntu to establish a golang-1.18 environment with latest docker and recommended kind. Built the dev-env successfully; had issues with make test, but they are entirely unrelated to anything I touched. Ultimate test was
```
FOCUS=log-format make kind-e2e-test
...
Ginkgo ran 1 suite in 6m29.7437865s
Test Suite Passed
```

## Checklist:
<!--- Go over all the following points, and put an `x` in all the boxes that apply. -->
<!--- If you're unsure about any of these, don't hesitate to ask. We're here to help! -->
- [x] My change requires a change to the documentation.
- [x] I have updated the documentation accordingly.
- [x] I've read the [CONTRIBUTION](https://github.com/kubernetes/ingress-nginx/blob/main/CONTRIBUTING.md) guide
- [x] I have added tests to cover my changes.
- [x] All new and existing tests passed.

I did not update docs/e2e-tests.md.

* gofmt -s ./internal/ingress/controller/config/config.go

test/e2e/settings/log-format.go

@@ -35,12 +35,12 @@ var _ = framework.DescribeSetting("log-format-*", func() {
 		f.EnsureIngress(framework.NewSingleIngress(host, "/", host, f.Namespace, framework.EchoService, 80, nil))
 	})
 
-	ginkgo.Context("Check log-format-escape-json", func() {
+	ginkgo.Context("Check log-format-escape-json and log-format-escape-none", func() {
 
-		ginkgo.It("should disable the log-format-escape-json by default", func() {
+		ginkgo.It("should not configure log-format escape by default", func() {
 			f.WaitForNginxConfiguration(
 				func(cfg string) bool {
-					return !strings.Contains(cfg, "log_format upstreaminfo escape=json")
+					return !strings.Contains(cfg, "log_format upstreaminfo escape")
 				})
 		})
 
@@ -59,9 +59,25 @@ var _ = framework.DescribeSetting("log-format-*", func() {
 					return !strings.Contains(cfg, "log_format upstreaminfo escape=json")
 				})
 		})
+
+		ginkgo.It("should enable the log-format-escape-none", func() {
+			f.UpdateNginxConfigMapData("log-format-escape-none", "true")
+			f.WaitForNginxConfiguration(
+				func(cfg string) bool {
+					return strings.Contains(cfg, "log_format upstreaminfo escape=none")
+				})
+		})
+
+		ginkgo.It("should disable the log-format-escape-none", func() {
+			f.UpdateNginxConfigMapData("log-format-escape-none", "false")
+			f.WaitForNginxConfiguration(
+				func(cfg string) bool {
+					return !strings.Contains(cfg, "log_format upstreaminfo escape=none")
+				})
+		})
 	})
 
-	ginkgo.Context("Check log-format-upstream with log-format-escape-json", func() {
+	ginkgo.Context("Check log-format-upstream with log-format-escape-json and log-format-escape-none", func() {
 
 		ginkgo.It("log-format-escape-json enabled", func() {
 			f.SetNginxConfigMapData(map[string]string{
@@ -86,7 +102,7 @@ var _ = framework.DescribeSetting("log-format-*", func() {
 			assert.Contains(ginkgo.GinkgoT(), logs, `{"my_header1":"Here is \"header1\" with json escape", "my_header2":""}`)
 		})
 
-		ginkgo.It("log-format-escape-json disabled", func() {
+		ginkgo.It("log-format default escape", func() {
 			f.SetNginxConfigMapData(map[string]string{
 				"log-format-escape-json": "false",
 				"log-format-upstream":    "\"{\"my_header3\":\"$http_header3\", \"my_header4\":\"$http_header4\"}\"",
@@ -94,19 +110,42 @@ var _ = framework.DescribeSetting("log-format-*", func() {
 
 			f.WaitForNginxConfiguration(
 				func(cfg string) bool {
-					return !strings.Contains(cfg, "log_format upstreaminfo escape=json")
+					return !strings.Contains(cfg, "log_format upstreaminfo escape")
 				})
 
 			f.HTTPTestClient().
 				GET("/").
 				WithHeader("Host", host).
-				WithHeader("header3", `Here is "header3" with json escape`).
+				WithHeader("header3", `Here is "header3" with default escape`).
 				Expect().
 				Status(http.StatusOK)
 
 			logs, err := f.NginxLogs()
 			assert.Nil(ginkgo.GinkgoT(), err, "obtaining nginx logs")
-			assert.Contains(ginkgo.GinkgoT(), logs, `{"my_header3":"Here is \x22header3\x22 with json escape", "my_header4":"-"}`)
+			assert.Contains(ginkgo.GinkgoT(), logs, `{"my_header3":"Here is \x22header3\x22 with default escape", "my_header4":"-"}`)
+		})
+
+		ginkgo.It("log-format-escape-none enabled", func() {
+			f.SetNginxConfigMapData(map[string]string{
+				"log-format-escape-none": "true",
+				"log-format-upstream":    "\"{\"my_header5\":\"$http_header5\", \"my_header6\":\"$http_header6\"}\"",
+			})
+
+			f.WaitForNginxConfiguration(
+				func(cfg string) bool {
+					return strings.Contains(cfg, "log_format upstreaminfo escape=none")
+				})
+
+			f.HTTPTestClient().
+				GET("/").
+				WithHeader("Host", host).
+				WithHeader("header5", `Here is "header5" with none escape`).
+				Expect().
+				Status(http.StatusOK)
+
+			logs, err := f.NginxLogs()
+			assert.Nil(ginkgo.GinkgoT(), err, "obtaining nginx logs")
+			assert.Contains(ginkgo.GinkgoT(), logs, `{"my_header5":"Here is "header5" with none escape", "my_header6":""}`)
 		})
 	})
 })