Allow configuration of invoke URL pattern via environment variables

Author: Richard Connon

api/server/fn_annotator.go

@@ -8,22 +8,24 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
-//FnAnnotator Is used to inject trigger context (such as request URLs) into outbound trigger resources
+//FnAnnotator Is used to inject fn context (such as request URLs) into outbound fn resources
 type FnAnnotator interface {
 	// Annotates a trigger on read
 	AnnotateFn(ctx *gin.Context, a *models.App, fn *models.Fn) (*models.Fn, error)
 }
 
-type requestBasedFnAnnotator struct{}
+type requestBasedFnAnnotator struct {
+	group, template string
+}
 
-func annotateFnWithBaseURL(baseURL string, app *models.App, fn *models.Fn) (*models.Fn, error) {
+func annotateFnWithBaseURL(baseURL, group, template string, app *models.App, fn *models.Fn) (*models.Fn, error) {
 
 	baseURL = strings.TrimSuffix(baseURL, "/")
-	src := strings.TrimPrefix(fn.ID, "/")
-	triggerPath := fmt.Sprintf("%s/invoke/%s", baseURL, src)
+	path := strings.Replace(template, ":fn_id", fn.ID, -1)
+	invokePath := fmt.Sprintf("%s%s%s", baseURL, group, path)
 
 	newT := fn.Clone()
-	newAnnotations, err := newT.Annotations.With(models.FnInvokeEndpointAnnotation, triggerPath)
+	newAnnotations, err := newT.Annotations.With(models.FnInvokeEndpointAnnotation, invokePath)
 	if err != nil {
 		return nil, err
 	}
@@ -39,25 +41,25 @@ func (tp *requestBasedFnAnnotator) AnnotateFn(ctx *gin.Context, app *models.App,
 		scheme = "https"
 	}
 
-	return annotateFnWithBaseURL(fmt.Sprintf("%s://%s", scheme, ctx.Request.Host), app, t)
+	return annotateFnWithBaseURL(fmt.Sprintf("%s://%s", scheme, ctx.Request.Host), tp.group, tp.template, app, t)
 }
 
 //NewRequestBasedFnAnnotator creates a FnAnnotator that inspects the incoming request host and port, and uses this to generate fn invoke endpoint URLs based on those
-func NewRequestBasedFnAnnotator() FnAnnotator {
-	return &requestBasedFnAnnotator{}
+func NewRequestBasedFnAnnotator(group, template string) FnAnnotator {
+	return &requestBasedFnAnnotator{group: group, template: template}
 }
 
 type staticURLFnAnnotator struct {
-	baseURL string
+	baseURL, group, template string
 }
 
 //NewStaticURLFnAnnotator annotates triggers bases on a given, specified URL base - e.g. "https://my.domain" --->  "https://my.domain/t/app/source"
-func NewStaticURLFnAnnotator(baseURL string) FnAnnotator {
+func NewStaticURLFnAnnotator(baseURL, group, template string) FnAnnotator {
 
-	return &staticURLFnAnnotator{baseURL: baseURL}
+	return &staticURLFnAnnotator{baseURL: baseURL, group: group, template: template}
 }
 
 func (s *staticURLFnAnnotator) AnnotateFn(ctx *gin.Context, app *models.App, trigger *models.Fn) (*models.Fn, error) {
-	return annotateFnWithBaseURL(s.baseURL, app, trigger)
+	return annotateFnWithBaseURL(s.baseURL, s.group, s.template, app, trigger)
 
 }

api/server/server.go

@@ -119,6 +119,18 @@ const (
 	// EnvMaxRequestSize sets the limit in bytes for any API request's length.
 	EnvMaxRequestSize = "FN_MAX_REQUEST_SIZE"
 
+	// EnvInvokeGroup sets the API group for the invoke endpoint
+	EnvInvokeGroup = "FN_INVOKE_GROUP"
+
+	// EnvInvokeTemplate sets the API path for the invoke endpoing
+	EnvInvokeTemplate = "FN_INVOKE_PATH"
+
+	// DefaultInvokeGroup is "/v2"
+	DefaultInvokeGroup = "/v2"
+
+	// DefaultInvokeTemplate is "/:fn_id"
+	DefaultInvokeTemplate = "/:fn_id"
+
 	// DefaultLogFormat is text
 	DefaultLogFormat = "text"
 
@@ -266,14 +278,16 @@ func NewFromEnv(ctx context.Context, opts ...Option) *Server {
 
 	opts = append(opts, LimitRequestBody(int64(getEnvInt(EnvMaxRequestSize, 0))))
 
+	invokeGroup := getEnv(EnvInvokeGroup, DefaultInvokeGroup)
+	invokeTemplate := getEnv(EnvInvokeTemplate, DefaultInvokeTemplate)
 	publicLBURL := getEnv(EnvPublicLoadBalancerURL, "")
 	if publicLBURL != "" {
 		logrus.Infof("using LB Base URL: '%s'", publicLBURL)
 		opts = append(opts, WithTriggerAnnotator(NewStaticURLTriggerAnnotator(publicLBURL)))
-		opts = append(opts, WithFnAnnotator(NewStaticURLFnAnnotator(publicLBURL)))
+		opts = append(opts, WithFnAnnotator(NewStaticURLFnAnnotator(publicLBURL, invokeGroup, invokeTemplate)))
 	} else {
 		opts = append(opts, WithTriggerAnnotator(NewRequestBasedTriggerAnnotator()))
-		opts = append(opts, WithFnAnnotator(NewRequestBasedFnAnnotator()))
+		opts = append(opts, WithFnAnnotator(NewRequestBasedFnAnnotator(invokeGroup, invokeTemplate)))
 	}
 
 	// Agent handling depends on node type and several other options so it must be the last processed option.
@@ -1105,9 +1119,7 @@ func (s *Server) bindHandlers(ctx context.Context) {
 	profilerSetup(admin, "/debug")
 
 	// Pure runners don't have any route, they have grpc
-	switch s.nodeType {
-
-	case ServerTypeFull, ServerTypeAPI:
+	if s.nodeType == ServerTypeFull || s.nodeType == ServerTypeAPI {
 		cleanv2 := engine.Group("/v2")
 		v2 := cleanv2.Group("")
 		v2.Use(s.apiMiddlewareWrapper())
@@ -1159,17 +1171,16 @@ func (s *Server) bindHandlers(ctx context.Context) {
 		}
 	}
 
-	switch s.nodeType {
-	case ServerTypeFull, ServerTypeLB, ServerTypeRunner:
+	if s.nodeType == ServerTypeFull || s.nodeType == ServerTypeLB || s.nodeType == ServerTypeRunner {
 		if !s.noHTTTPTriggerEndpoint {
 			lbTriggerGroup := engine.Group("/t")
 			lbTriggerGroup.Any("/:app_name", s.handleHTTPTriggerCall)
 			lbTriggerGroup.Any("/:app_name/*trigger_source", s.handleHTTPTriggerCall)
 		}
 
 		if !s.noFnInvokeEndpoint {
-			lbFnInvokeGroup := engine.Group("/invoke")
-			lbFnInvokeGroup.POST("/:fn_id", s.handleFnInvokeCall)
+			lbFnInvokeGroup := engine.Group(getEnv(EnvInvokeGroup, DefaultInvokeGroup))
+			lbFnInvokeGroup.POST(getEnv(EnvInvokeTemplate, DefaultInvokeTemplate), s.handleFnInvokeCall)
 		}
 	}