From 52e0e838e93343d95685ac74b06eab73ccca43fa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Toma=C5=BE=20Jerman?= <tomaz.jerman121@gmail.com>
Date: Mon, 27 Sep 2021 14:11:40 +0200
Subject: [PATCH] Prevent API GW filters from overwriting the same registry
 struct

---
 pkg/apigw/filter/postfilter.go  | 8 ++++++++
 pkg/apigw/filter/prefilter.go   | 8 ++++++++
 pkg/apigw/filter/processer.go   | 8 ++++++++
 pkg/apigw/filter/proxy/proxy.go | 4 ++++
 pkg/apigw/registry/registry.go  | 2 +-
 pkg/apigw/service_test.go       | 1 +
 pkg/apigw/types/handler.go      | 1 +
 pkg/apigw/types/test.go         | 4 ++++
 8 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/pkg/apigw/filter/postfilter.go b/pkg/apigw/filter/postfilter.go
index 0460eec71..7f983e01a 100644
--- a/pkg/apigw/filter/postfilter.go
+++ b/pkg/apigw/filter/postfilter.go
@@ -61,6 +61,10 @@ func NewRedirection() (e *redirection) {
 	return
 }
 
+func (h redirection) New() types.Handler {
+	return NewRedirection()
+}
+
 func (h redirection) String() string {
 	return fmt.Sprintf("apigw filter %s (%s)", h.Name, h.Label)
 }
@@ -109,6 +113,10 @@ func NewDefaultJsonResponse() (e *defaultJsonResponse) {
 	return
 }
 
+func (h defaultJsonResponse) New() types.Handler {
+	return NewDefaultJsonResponse()
+}
+
 func (h defaultJsonResponse) String() string {
 	return fmt.Sprintf("apigw filter %s (%s)", h.Name, h.Label)
 }
diff --git a/pkg/apigw/filter/prefilter.go b/pkg/apigw/filter/prefilter.go
index 5f81a3984..964ee2bdc 100644
--- a/pkg/apigw/filter/prefilter.go
+++ b/pkg/apigw/filter/prefilter.go
@@ -56,6 +56,10 @@ func NewHeader() (v *header) {
 	return
 }
 
+func (h header) New() types.Handler {
+	return NewHeader()
+}
+
 func (h header) String() string {
 	return fmt.Sprintf("apigw filter %s (%s)", h.Name, h.Label)
 }
@@ -133,6 +137,10 @@ func NewQueryParam() (v *queryParam) {
 	return
 }
 
+func (h queryParam) New() types.Handler {
+	return NewQueryParam()
+}
+
 func (h queryParam) String() string {
 	return fmt.Sprintf("apigw filter %s (%s)", h.Name, h.Label)
 }
diff --git a/pkg/apigw/filter/processer.go b/pkg/apigw/filter/processer.go
index 0d17ec5aa..00446bb3f 100644
--- a/pkg/apigw/filter/processer.go
+++ b/pkg/apigw/filter/processer.go
@@ -66,6 +66,10 @@ func NewWorkflow(wf WfExecer) (p *workflow) {
 	return
 }
 
+func (h workflow) New() types.Handler {
+	return NewWorkflow(h.d)
+}
+
 func (h workflow) String() string {
 	return fmt.Sprintf("apigw filter %s (%s)", h.Name, h.Label)
 }
@@ -185,6 +189,10 @@ func NewPayload(l *zap.Logger) (p *processerPayload) {
 	return
 }
 
+func (h processerPayload) New() types.Handler {
+	return NewPayload(h.log)
+}
+
 func (h processerPayload) String() string {
 	return fmt.Sprintf("apigw filter %s (%s)", h.Name, h.Label)
 }
diff --git a/pkg/apigw/filter/proxy/proxy.go b/pkg/apigw/filter/proxy/proxy.go
index 6995b5dd3..861490c04 100644
--- a/pkg/apigw/filter/proxy/proxy.go
+++ b/pkg/apigw/filter/proxy/proxy.go
@@ -67,6 +67,10 @@ func New(l *zap.Logger, c *http.Client, s types.SecureStorager) (p *proxy) {
 	return
 }
 
+func (h proxy) New() types.Handler {
+	return New(h.log, h.c, h.s)
+}
+
 func (h proxy) String() string {
 	return fmt.Sprintf("apigw filter %s (%s)", h.Name, h.Label)
 }
diff --git a/pkg/apigw/registry/registry.go b/pkg/apigw/registry/registry.go
index a3d1739f7..fd59c3899 100644
--- a/pkg/apigw/registry/registry.go
+++ b/pkg/apigw/registry/registry.go
@@ -45,7 +45,7 @@ func (r *Registry) Get(identifier string) (types.Handler, error) {
 		return nil, fmt.Errorf("could not get element from registry: %s", identifier)
 	}
 
-	return f, nil
+	return f.New(), nil
 }
 
 func (r *Registry) All() (list types.FilterMetaList) {
diff --git a/pkg/apigw/service_test.go b/pkg/apigw/service_test.go
index fe64da38b..a89901b6a 100644
--- a/pkg/apigw/service_test.go
+++ b/pkg/apigw/service_test.go
@@ -142,6 +142,7 @@ func Test_serviceInit(t *testing.T) {
 					},
 				},
 				reg: map[string]types.Handler{"testExistingFilter": &mockExistingHandler{
+					MockHandler: &types.MockHandler{},
 					merge: func(params []byte) (types.Handler, error) {
 						return nil, errors.New("testttt")
 					},
diff --git a/pkg/apigw/types/handler.go b/pkg/apigw/types/handler.go
index 6ab71497b..3dddc5cea 100644
--- a/pkg/apigw/types/handler.go
+++ b/pkg/apigw/types/handler.go
@@ -18,6 +18,7 @@ type (
 		HTTPHandler
 		fmt.Stringer
 
+		New() Handler
 		Merge([]byte) (Handler, error)
 		Meta() FilterMeta
 	}
diff --git a/pkg/apigw/types/test.go b/pkg/apigw/types/test.go
index b4c812cd7..ba21a1ca1 100644
--- a/pkg/apigw/types/test.go
+++ b/pkg/apigw/types/test.go
@@ -32,6 +32,10 @@ type (
 	MockRoundTripper func(*http.Request) (*http.Response, error)
 )
 
+func (h MockHandler) New() Handler {
+	return MockHandler{}
+}
+
 func (h MockHandler) String() string {
 	return "MockHandler"
 }