Remove CORS configuration from subscription (#458)

Author: mthenw

docs/api.md

@@ -98,14 +98,6 @@ HTTP subscription response depends on [response object](#respond-to-an-http-requ
 * `404 Not Found` if there is no backing function registered for requested HTTP endpoint
 * `500 Internal Server Error` if the function invocation failed or the backing function didn't return [HTTP response object](#respond-to-an-http-request-event)
 
-##### CORS
-
-By default cross-origin resource sharing (CORS) is disabled for `sync` subscriptions. It can be enabled and configured
-per-subscription basis.
-
-Event Gateway handles preflight `OPTIONS` requests for you. You don't need to setup subscription for `OPTIONS` method
-because the Event Gateway will respond with all appropriate headers.
-
 #### Path parameters
 
 The Event Gateway allows creating HTTP subscription with parameterized paths. Every path segment prefixed with `:` is
@@ -134,11 +126,6 @@ To respond to an HTTP event a function needs to return object with following fie
 
 Currently, the event gateway supports only string responses.
 
-### CORS
-
-Events API supports CORS requests which means that any origin can emit a custom event. In case of `sync` subscriptions CORS is
-configured per-subscription basis.
-
 ## Configuration API
 
 [OpenAPI spec](./openapi/openapi-config-api.yaml)
@@ -309,11 +296,6 @@ JSON object:
 * `functionId` - `string` - ID of function to receive events
 * `path` - `string` - optional, URL path under which events (HTTP requests) are accepted, default: `/`
 * `method` - `string` - optional, HTTP method that accepts requests, default: `POST`
-* `cors` - `object` - optional, by default CORS is disabled for `sync` subscriptions. When set to empty object CORS configuration will use default values for all fields below. Available fields:
-  * `origins` - `array` of `string` - list of allowed origins. An origin may contain a wildcard (\*) to replace 0 or more characters (i.e.: http://\*.domain.com), default: `*`
-  * `methods` - `array` of `string` - list of allowed methods, default: `HEAD`, `GET`, `POST`
-  * `headers` - `array` of `string` - list of allowed headers, default: `Origin`, `Accept`, `Content-Type`
-  * `allowCredentials` - `bool` - default: false
 
 **Response**
 
@@ -331,7 +313,6 @@ JSON object:
 * `functionId` - function ID
 * `method` - `string` - HTTP method that accepts requests
 * `path` - `string` - path that accepts requests, starts with `/`
-* `cors` - `object` - optional, CORS configuration
 
 ---
 
@@ -350,11 +331,6 @@ _Note that `type`, `eventType`, `functionId`, `path`, and `method` may not be up
 * `functionId` - `string` - ID of function to receive events
 * `path` - `string` - optional, URL path under which events (HTTP requests) are accepted, default: `/`
 * `method` - `string` - optional, HTTP method that accepts requests, default: `POST`
-* `cors` - `object` - optional, by default CORS is disabled for `sync` subscriptions. When set to empty object CORS configuration will use default values for all fields below. Available fields:
-  * `origins` - `array` of `string` - list of allowed origins. An origin may contain a wildcard (\*) to replace 0 or more characters (i.e.: http://\*.domain.com), default: `*`
-  * `methods` - `array` of `string` - list of allowed methods, default: `HEAD`, `GET`, `POST`
-  * `headers` - `array` of `string` - list of allowed headers, default: `Origin`, `Accept`, `Content-Type`
-  * `allowCredentials` - `bool` - default: false
 
 **Response**
 
@@ -373,7 +349,6 @@ JSON object:
 * `functionId` - function ID
 * `method` - `string` - HTTP method that accepts requests
 * `path` - `string` - path that accepts requests, starts with `/`
-* `cors` - `object` - optional, CORS configuration
 
 ---
 
@@ -414,7 +389,6 @@ JSON object:
   * `functionId` - function ID
   * `method` - `string` - HTTP method that accepts requests
   * `path` - `string` - path that accepts requests, starts with `/`
-  * `cors` - `object` - optional, CORS configuration
 
 #### Get Subscription
 
@@ -438,7 +412,6 @@ JSON object:
 * `functionId` - function ID
 * `method` - `string` - HTTP method that accepts requests
 * `path` - `string` - path that accepts requests, starts with `/`
-* `cors` - `object` - optional, CORS configuration
 
 ### Prometheus Metrics
 

docs/openapi/openapi-config-api.yaml

@@ -290,8 +290,6 @@ components:
           $ref: '#/components/schemas/Path'
         method:
           $ref: '#/components/schemas/Method'
-        cors:
-          $ref: '#/components/schemas/CORS'
     Subscriptions:
       type: object
       properties:
@@ -400,32 +398,6 @@ components:
       properties:
         message:
           type: string
-    CORS:
-      type: object
-      description: "(only for HTTP event) CORS configuration for HTTP event subscription"
-      default: null
-      properties:
-        origins:
-          type: array
-          description: "list of allowed origins. An origin may contain a wildcard (*) to replace 0 or more characters (i.e.: http://*.domain.com)"
-          items:
-            type: string
-          default: ["*"]
-        methods:
-          type: array
-          description: "list of allowed methods"
-          items:
-            type: string
-          default: ["HEAD", "GET", "POST"]
-        headers:
-          type: array
-          description: "list of allowed headers"
-          items:
-            type: string
-          default: ["Origin", "Accept", "Content-Type"]
-        allowCredentials:
-          type: boolean
-          default: false
     Errors:
       type: object
       description: "error response object"
@@ -498,8 +470,6 @@ components:
                 $ref: '#/components/schemas/Path'
               method:
                 $ref: '#/components/schemas/Method'
-              cors:
-                $ref: '#/components/schemas/CORS'
     UpdateSubscription:
       description: "subscription update request body"
       content:
@@ -517,8 +487,6 @@ components:
                 $ref: '#/components/schemas/Path'
               method:
                 $ref: '#/components/schemas/Method'
-              cors:
-                $ref: '#/components/schemas/CORS'
   responses:
     Error:
       description: "internal server error"

httpapi/httpapi_test.go

@@ -514,17 +514,9 @@ func TestUpdateSubscription(t *testing.T) {
 		FunctionID: "func",
 		Method:     "GET",
 		Path:       "/",
-		CORS: &subscription.CORS{
-			Origins:          []string{"*"},
-			Methods:          []string{"HEAD", "GET", "POST"},
-			Headers:          []string{"Origin", "Accept", "Content-Type"},
-			AllowCredentials: false,
-		},
 	}
 	updatedValue := []byte(`{"space":"default","subscriptionId":"testid","type":"sync",` +
-		`"eventType":"http.request","functionId":"func","method":"GET","path":"/",` +
-		`"cors":{"origins":["*"],"methods":["HEAD","GET","POST"],` +
-		`"headers":["Origin","Accept","Content-Type"],"allowCredentials":false}}`)
+		`"eventType":"http.request","functionId":"func","method":"GET","path":"/"}`)
 
 	t.Run("subscription updated", func(t *testing.T) {
 		subscriptions.EXPECT().UpdateSubscription(subscription.ID("testid"), updateSub).Return(updateSub, nil)

internal/cache/subscription_cache.go

@@ -49,7 +49,7 @@ func (c *subscriptionCache) Modified(k string, v []byte) {
 			root = pathtree.NewNode()
 			c.endpoints[s.Method] = root
 		}
-		err := root.AddRoute(s.Path, s.Space, s.FunctionID, s.CORS)
+		err := root.AddRoute(s.Path, s.Space, s.FunctionID)
 		if err != nil {
 			c.log.Error("Could not add path to the tree.", zap.Error(err), zap.String("path", s.Path), zap.String("method", s.Method))
 		}

internal/cache/subscription_cache_test.go

@@ -5,7 +5,6 @@ import (
 
 	"github.com/serverless/event-gateway/function"
 	"github.com/serverless/event-gateway/libkv"
-	"github.com/serverless/event-gateway/subscription"
 	"github.com/stretchr/testify/assert"
 
 	"go.uber.org/zap"
@@ -59,29 +58,11 @@ func TestSubscriptionCacheModifiedSyncSubscription(t *testing.T) {
 		"path": "/b",
 		"method": "GET"}`))
 
-	space, id, _, _ := scache.endpoints["GET"].Resolve("/a")
+	space, id, _ := scache.endpoints["GET"].Resolve("/a")
 	assert.Equal(t, function.ID("testfunc1"), *id)
 	assert.Equal(t, "default", space)
 }
 
-func TestSubscriptionCacheModifiedCORSConfiguration(t *testing.T) {
-	scache := newSubscriptionCache(zap.NewNop())
-
-	scache.Modified("testsub1", []byte(`{
-		"subscriptionId":"testsub1",
-		"type": "sync",
-		"eventType": "http.request",
-		"functionId": "testfunc1",
-		"path": "/a",
-		"method": "GET",
-		"cors": {
-			"origins": ["http://example.com"]
-		}}`))
-
-	_, _, _, corsConfig := scache.endpoints["GET"].Resolve("/a")
-	assert.Equal(t, &subscription.CORS{Origins: []string{"http://example.com"}}, corsConfig)
-}
-
 func TestSubscriptionCacheModifiedEventsWrongPayload(t *testing.T) {
 	scache := newSubscriptionCache(zap.NewNop())
 
@@ -139,7 +120,7 @@ func TestSubscriptionCacheModifiedHTTPSubscriptionDeleted(t *testing.T) {
 		"path": "/",
 		"method": "GET"}`))
 
-	space, id, _, _ := scache.endpoints["GET"].Resolve("/")
+	space, id, _ := scache.endpoints["GET"].Resolve("/")
 	assert.Nil(t, id)
 	assert.Equal(t, "", space)
 }

internal/cache/target.go

@@ -40,7 +40,7 @@ func (tc *Target) SyncSubscriber(method, path string, eventType eventpkg.TypeNam
 		return nil
 	}
 
-	space, functionID, params, cors := root.Resolve(path)
+	space, functionID, params := root.Resolve(path)
 	if functionID == nil {
 		return nil
 	}
@@ -49,7 +49,6 @@ func (tc *Target) SyncSubscriber(method, path string, eventType eventpkg.TypeNam
 		Space:      space,
 		FunctionID: *functionID,
 		Params:     params,
-		CORS:       cors,
 	}
 }
 

internal/pathtree/tree.go

@@ -6,7 +6,6 @@ import (
 	"strings"
 
 	"github.com/serverless/event-gateway/function"
-	"github.com/serverless/event-gateway/subscription"
 )
 
 // Node is a data structure, inspired by prefix tree, used for routing HTTP requests in the Event Gateway. It's used for creating tree structure
@@ -16,7 +15,6 @@ type Node struct {
 	children    map[string]*Node
 	space       string
 	functionID  *function.ID
-	cors        *subscription.CORS
 	parameter   string
 	isStatic    bool
 	isParameter bool
@@ -35,11 +33,10 @@ type Params map[string]string
 
 // AddRoute adds route to the tree. This function will panic in case of adding conflicting parameterized paths.
 // nolint: gocyclo
-func (n *Node) AddRoute(route string, space string, functionID function.ID, corsConfig *subscription.CORS) error {
+func (n *Node) AddRoute(route string, space string, functionID function.ID) error {
 	if route == "/" {
 		n.space = space
 		n.functionID = &functionID
-		n.cors = corsConfig
 		return nil
 	}
 
@@ -62,7 +59,6 @@ func (n *Node) AddRoute(route string, space string, functionID function.ID, cors
 				if i == len(segments)-1 {
 					currentNode.children[segment].space = space
 					currentNode.children[segment].functionID = &functionID
-					currentNode.children[segment].cors = corsConfig
 					return nil
 				}
 				currentNode = currentNode.children[segment]
@@ -96,7 +92,6 @@ func (n *Node) AddRoute(route string, space string, functionID function.ID, cors
 			}
 			currentNode.children[segment].space = space
 			currentNode.children[segment].functionID = &functionID
-			currentNode.children[segment].cors = corsConfig
 			return nil
 		}
 		currentNode = currentNode.children[segment]
@@ -110,7 +105,6 @@ func (n *Node) DeleteRoute(route string) error {
 	if route == "/" {
 		n.space = ""
 		n.functionID = nil
-		n.cors = nil
 		return nil
 	}
 
@@ -129,7 +123,6 @@ func (n *Node) DeleteRoute(route string) error {
 			} else {
 				currentNode.children[segment].space = ""
 				currentNode.children[segment].functionID = nil
-				currentNode.children[segment].cors = nil
 			}
 
 			return nil
@@ -143,12 +136,12 @@ func (n *Node) DeleteRoute(route string) error {
 
 // Resolve takes request URL path and traverse the tree trying find corresponding route.
 // nolint: gocyclo
-func (n *Node) Resolve(path string) (string, *function.ID, Params, *subscription.CORS) {
+func (n *Node) Resolve(path string) (string, *function.ID, Params) {
 	if path == "/" {
 		if n.functionID != nil {
-			return n.space, n.functionID, nil, n.cors
+			return n.space, n.functionID, nil
 		}
-		return "", nil, nil, nil
+		return "", nil, nil
 	}
 
 	segments := toSegments(path)
@@ -162,7 +155,7 @@ func (n *Node) Resolve(path string) (string, *function.ID, Params, *subscription
 			// look for param
 			child, exists = first(currentNode.children)
 			if !exists || !(child.isParameter || child.isWildcard) {
-				return "", nil, nil, nil
+				return "", nil, nil
 			}
 		}
 		currentNode = child
@@ -174,15 +167,15 @@ func (n *Node) Resolve(path string) (string, *function.ID, Params, *subscription
 		if currentNode.isWildcard {
 			// add missing parts
 			params[currentNode.parameter] = strings.Join(segments[i:], "/")
-			return currentNode.space, currentNode.functionID, params, currentNode.cors
+			return currentNode.space, currentNode.functionID, params
 		}
 
 		if i == len(segments)-1 {
-			return currentNode.space, currentNode.functionID, params, currentNode.cors
+			return currentNode.space, currentNode.functionID, params
 		}
 	}
 
-	return "", nil, nil, nil
+	return "", nil, nil
 }
 
 func toSegments(route string) []string {