feat: pass query parameters to the hydrators (#479)

Co-authored-by: Krystian Cieslik <[email protected]>

pipeline/mutate/mutator_hydrator.go

@@ -167,6 +167,12 @@ func (a *MutatorHydrator) Mutate(r *http.Request, session *authn.AuthenticationS
 	if err != nil {
 		return errors.WithStack(err)
 	}
+
+	if r.URL != nil {
+		q := r.URL.Query()
+		req.URL.RawQuery = q.Encode()
+	}
+
 	for key, values := range r.Header {
 		for _, value := range values {
 			req.Header.Add(key, value)

pipeline/mutate/mutator_hydrator_test.go

@@ -7,6 +7,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
+	"net/url"
 	"testing"
 
 	"github.com/julienschmidt/httprouter"
@@ -324,6 +325,27 @@ func TestMutatorHydrator(t *testing.T) {
 				Match:   newAuthenticationSession(setExtra(sampleKey, sampleValue)),
 				Err:     nil,
 			},
+			"Pass Query Parameters": {
+				Setup: func(t *testing.T) http.Handler {
+					router := httprouter.New()
+					router.POST("/", func(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
+						q := r.URL.Query()
+						assert.Equal(t, len(q), 2)
+						assert.Equal(t, q["a"], []string{"b"})
+						assert.Equal(t, q["c"], []string{"&12"})
+
+						_, err = w.Write([]byte(`{}`))
+						require.NoError(t, err)
+					})
+					return router
+				},
+				Session: newAuthenticationSession(),
+				Rule:    &rule.Rule{ID: "test-rule"},
+				Config:  defaultConfigForMutator(),
+				Request: &http.Request{URL: &url.URL{RawQuery: "a=b&c=%2612"}},
+				Match:   newAuthenticationSession(),
+				Err:     nil,
+			},
 		}
 
 		for testName, specs := range testMap {