Enable prefix based routing (#2047)

* Enable prefix based routing

Signed-off-by: Harsh Thakur <harshthakur9030@gmail.com>

* Optimize checking condition

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

* Disable few tests

* disable router modification for now

* run code generator

* Collect fission dump in CI

* Enable all tests back

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

* Remove unwanted code

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

* Add prefix support at more places and couple of todo's

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

* Few more changes

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

* Improve function trim support

* Support for prefix based urls in fission function test

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

* multi route for fission function test

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

* Improve validations in trigger creations

* Adjust leading / in url from fission

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

* Change suburl to subpath for function test

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

Co-authored-by: Sanket Sudake <sanketsudake@gmail.com>

pkg/router/functionHandler.go

@@ -27,6 +27,7 @@ import (
 	"net/http"
 	"net/http/httputil"
 	"net/url"
+	"strings"
 	"time"
 
 	"github.com/pkg/errors"
@@ -39,6 +40,7 @@ import (
 	"github.com/fission/fission/pkg/error/network"
 	executorClient "github.com/fission/fission/pkg/executor/client"
 	"github.com/fission/fission/pkg/throttler"
+	"github.com/fission/fission/pkg/utils"
 )
 
 const (
@@ -220,12 +222,26 @@ func (roundTripper *RetryingRoundTripper) RoundTrip(req *http.Request) (*http.Re
 			req.URL.Scheme = roundTripper.serviceURL.Scheme
 			req.URL.Host = roundTripper.serviceURL.Host
 
-			// To keep the function run container simple, it
-			// doesn't do any routing.  In the future if we have
-			// multiple functions per container, we could use the
-			// function metadata here.
-			// leave the query string intact (req.URL.RawQuery)
-			req.URL.Path = "/"
+			// With addition of routing support from functions if function supports routing,
+			// 1. we trim prefix url and forward request
+			// 2. otherwise we just keep default request to root path
+			// We leave the query string intact (req.URL.RawQuery) where as we manipuate
+			// req.URL.Path according to httpTrigger specification.
+			prefixTrim := ""
+			functionURL := utils.UrlForFunction(fnMeta.Name, fnMeta.Namespace)
+			if roundTripper.funcHandler.httpTrigger != nil && roundTripper.funcHandler.httpTrigger.Spec.Prefix != nil && *roundTripper.funcHandler.httpTrigger.Spec.Prefix != "" {
+				prefixTrim = *roundTripper.funcHandler.httpTrigger.Spec.Prefix
+			} else if strings.HasPrefix(req.URL.Path, functionURL) {
+				prefixTrim = functionURL
+			}
+			if prefixTrim != "" {
+				req.URL.Path = strings.TrimPrefix(req.URL.Path, prefixTrim)
+				if !strings.HasPrefix(req.URL.Path, "/") {
+					req.URL.Path = "/" + req.URL.Path
+				}
+			} else {
+				req.URL.Path = "/"
+			}
 
 			// Overwrite request host with internal host,
 			// or request will be blocked in some situations
@@ -608,7 +624,11 @@ func (fh functionHandler) collectFunctionMetric(start time.Time, rrt *RetryingRo
 	}
 	if fh.httpTrigger != nil {
 		httpMetricLabels.host = fh.httpTrigger.Spec.Host
-		httpMetricLabels.path = fh.httpTrigger.Spec.RelativeURL
+		if fh.httpTrigger.Spec.Prefix != nil && *fh.httpTrigger.Spec.Prefix != "" {
+			httpMetricLabels.path = *fh.httpTrigger.Spec.Prefix
+		} else {
+			httpMetricLabels.path = fh.httpTrigger.Spec.RelativeURL
+		}
 	}
 
 	// Track metrics

pkg/router/httpTriggers.go

@@ -166,13 +166,18 @@ func (ts *HTTPTriggerSet) getRouter(fnTimeoutMap map[types.UID]int) *mux.Router
 				fh.function = fn
 			}
 		}
+		var ht *mux.Route
 
-		ht := muxRouter.HandleFunc(trigger.Spec.RelativeURL, fh.handler)
+		if trigger.Spec.Prefix != nil && *trigger.Spec.Prefix != "" {
+			ht = muxRouter.PathPrefix(*trigger.Spec.Prefix).HandlerFunc(fh.handler)
+		} else {
+			ht = muxRouter.HandleFunc(trigger.Spec.RelativeURL, fh.handler)
+		}
 		ht.Methods(trigger.Spec.Method)
 		if trigger.Spec.Host != "" {
 			ht.Host(trigger.Spec.Host)
 		}
-		if trigger.Spec.RelativeURL == "/" && trigger.Spec.Method == "GET" {
+		if trigger.Spec.Prefix == nil && trigger.Spec.RelativeURL == "/" && trigger.Spec.Method == "GET" {
 			homeHandled = true
 		}
 	}
@@ -202,7 +207,7 @@ func (ts *HTTPTriggerSet) getRouter(fnTimeoutMap map[types.UID]int) *mux.Router
 			functionTimeoutMap:     fnTimeoutMap,
 			unTapServiceTimeout:    ts.unTapServiceTimeout,
 		}
-		muxRouter.HandleFunc(utils.UrlForFunction(fn.ObjectMeta.Name, fn.ObjectMeta.Namespace), fh.handler)
+		muxRouter.PathPrefix(utils.UrlForFunction(fn.ObjectMeta.Name, fn.ObjectMeta.Namespace)).HandlerFunc(fh.handler)
 	}
 
 	// Healthz endpoint for the router.

pkg/router/util/util.go

@@ -27,6 +27,9 @@ import (
 func GetIngressSpec(namespace string, trigger *fv1.HTTPTrigger) *v1beta1.Ingress {
 	// TODO: remove backward compatibility
 	host, path := trigger.Spec.Host, trigger.Spec.RelativeURL
+	if trigger.Spec.Prefix != nil && *trigger.Spec.Prefix != "" {
+		path = *trigger.Spec.Prefix
+	}
 	if len(trigger.Spec.IngressConfig.Host) > 0 && len(trigger.Spec.IngressConfig.Path) > 0 {
 		host, path = trigger.Spec.IngressConfig.Host, trigger.Spec.IngressConfig.Path
 	}