Add header Host into mirror annotations (#8178)

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

@@ -131,6 +131,7 @@ You can add these Kubernetes annotations to specific Ingress objects to customiz
 |[nginx.ingress.kubernetes.io/modsecurity-snippet](#modsecurity)|string|
 |[nginx.ingress.kubernetes.io/mirror-request-body](#mirror)|string|
 |[nginx.ingress.kubernetes.io/mirror-target](#mirror)|string|
+|[nginx.ingress.kubernetes.io/mirror-host](#mirror)|string|
 
 ### Canary
 
@@ -941,6 +942,13 @@ By default the request-body is sent to the mirror backend, but can be turned off
 nginx.ingress.kubernetes.io/mirror-request-body: "off"
 ```
 
+Also by default header Host for mirrored requests will be set the same as a host part of uri in the "mirror-target" annotation. You can override it by "mirror-host" annotation:
+
+```yaml
+nginx.ingress.kubernetes.io/mirror-target: https://1.2.3.4/$request_uri
+nginx.ingress.kubernetes.io/mirror-host: "test.env.com"
+```
+
 **Note:** The mirror directive will be applied to all paths within the ingress resource.
 
 The request sent to the mirror is linked to the original request. If you have a slow mirror backend, then the original request will throttle.

internal/ingress/annotations/mirror/main.go

@@ -18,9 +18,9 @@ package mirror
 
 import (
 	"fmt"
+	"strings"
 
 	networking "k8s.io/api/networking/v1"
-
 	"k8s.io/ingress-nginx/internal/ingress/annotations/parser"
 	"k8s.io/ingress-nginx/internal/ingress/resolver"
 )
@@ -30,6 +30,7 @@ type Config struct {
 	Source      string `json:"source"`
 	RequestBody string `json:"requestBody"`
 	Target      string `json:"target"`
+	Host        string `json:"host"`
 }
 
 // Equal tests for equality between two Configuration types
@@ -54,6 +55,10 @@ func (m1 *Config) Equal(m2 *Config) bool {
 		return false
 	}
 
+	if m1.Host != m2.Host {
+		return false
+	}
+
 	return true
 }
 
@@ -85,5 +90,18 @@ func (a mirror) Parse(ing *networking.Ingress) (interface{}, error) {
 		config.Source = ""
 	}
 
+	config.Host, err = parser.GetStringAnnotation("mirror-host", ing)
+	if err != nil {
+		if config.Target != "" {
+			url, err := parser.StringToURL(config.Target)
+			if err != nil {
+				config.Host = ""
+			} else {
+				hostname := strings.Split(url.Hostname(), "$")
+				config.Host = hostname[0]
+			}
+		}
+	}
+
 	return config, nil
 }

internal/ingress/annotations/mirror/main_test.go

@@ -30,6 +30,7 @@ import (
 func TestParse(t *testing.T) {
 	requestBody := parser.GetAnnotationWithPrefix("mirror-request-body")
 	backendURL := parser.GetAnnotationWithPrefix("mirror-target")
+	host := parser.GetAnnotationWithPrefix("mirror-host")
 
 	ap := NewParser(&resolver.Mock{})
 	if ap == nil {
@@ -45,11 +46,43 @@ func TestParse(t *testing.T) {
 			Source:      ngxURI,
 			RequestBody: "on",
 			Target:      "https://test.env.com/$request_uri",
+			Host:        "test.env.com",
 		}},
 		{map[string]string{requestBody: "off"}, &Config{
 			Source:      "",
 			RequestBody: "off",
 			Target:      "",
+			Host:        "",
+		}},
+		{map[string]string{host: "test.env.com", backendURL: "http://some.test.env.com/$someparam"}, &Config{
+			Source:      ngxURI,
+			RequestBody: "on",
+			Target:      "http://some.test.env.com/$someparam",
+			Host:        "test.env.com",
+		}},
+		{map[string]string{backendURL: "IamNotAURL"}, &Config{
+			Source:      ngxURI,
+			RequestBody: "on",
+			Target:      "IamNotAURL",
+			Host:        "",
+		}},
+		{map[string]string{backendURL: "http://some.test.env.com:2121/$someparam=1&$someotherparam=2"}, &Config{
+			Source:      ngxURI,
+			RequestBody: "on",
+			Target:      "http://some.test.env.com:2121/$someparam=1&$someotherparam=2",
+			Host:        "some.test.env.com",
+		}},
+		{map[string]string{backendURL: "http://some.test.env.com", host: "someInvalidParm.%^&*()_=!@#'\""}, &Config{
+			Source:      ngxURI,
+			RequestBody: "on",
+			Target:      "http://some.test.env.com",
+			Host:        "someInvalidParm.%^&*()_=!@#'\"",
+		}},
+		{map[string]string{backendURL: "http://some.test.env.com", host: "_sbrubles-i\"@xpto:12345"}, &Config{
+			Source:      ngxURI,
+			RequestBody: "on",
+			Target:      "http://some.test.env.com",
+			Host:        "_sbrubles-i\"@xpto:12345",
 		}},
 	}
 

internal/ingress/controller/template/template.go

@@ -1667,10 +1667,11 @@ func buildMirrorLocations(locs []*ingress.Location) string {
 		mapped.Insert(loc.Mirror.Source)
 		buffer.WriteString(fmt.Sprintf(`location = %v {
 internal;
+proxy_set_header Host %v;
 proxy_pass %v;
 }
 
-`, loc.Mirror.Source, loc.Mirror.Target))
+`, loc.Mirror.Source, loc.Mirror.Host, loc.Mirror.Target))
 	}
 
 	return buffer.String()