routing: allows routes to be added to existing groups

this enables services to add routing to ex /api
without causing conflicts.

pkg/api/http_server.go

@@ -11,6 +11,7 @@ import (
 	"path"
 	"time"
 
+	"github.com/grafana/grafana/pkg/api/routing"
 	"github.com/prometheus/client_golang/prometheus"
 
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -43,10 +44,10 @@ type HTTPServer struct {
 	cache         *gocache.Cache
 	httpSrv       *http.Server
 
-	RouteRegister RouteRegister     `inject:""`
-	Bus           bus.Bus           `inject:""`
-	RenderService rendering.Service `inject:""`
-	Cfg           *setting.Cfg      `inject:""`
+	RouteRegister routing.RouteRegister `inject:""`
+	Bus           bus.Bus               `inject:""`
+	RenderService rendering.Service     `inject:""`
+	Cfg           *setting.Cfg          `inject:""`
 }
 
 func (hs *HTTPServer) Init() error {

pkg/api/route_register.go → pkg/api/routing/route_register.go

-package api
+package routing
 
 import (
 	"net/http"
+	"strings"
 
-	macaron "gopkg.in/macaron.v1"
+	"gopkg.in/macaron.v1"
 )
 
 type Router interface {
@@ -36,6 +37,9 @@ type RouteRegister interface {
 	// with a shared prefix route.
 	Group(string, func(RouteRegister), ...macaron.Handler)
 
+	// Insert adds more routes to an existing Group.
+	Insert(string, func(RouteRegister), ...macaron.Handler)
+
 	// Register iterates over all routes added to the RouteRegister
 	// and add them to the `Router` pass as an parameter.
 	Register(Router) *macaron.Router
@@ -67,6 +71,24 @@ type routeRegister struct {
 	groups          []*routeRegister
 }
 
+func (rr *routeRegister) Insert(pattern string, fn func(RouteRegister), handlers ...macaron.Handler) {
+
+	//loop over all groups at current level
+	for _, g := range rr.groups {
+
+		// apply routes if the prefix matches the pattern
+		if g.prefix == pattern {
+			g.Group("", fn)
+			break
+		}
+
+		// go down one level if the prefix can be find in the pattern
+		if strings.HasPrefix(pattern, g.prefix) {
+			g.Insert(pattern, fn)
+		}
+	}
+}
+
 func (rr *routeRegister) Group(pattern string, fn func(rr RouteRegister), handlers ...macaron.Handler) {
 	group := &routeRegister{
 		prefix:          rr.prefix + pattern,

pkg/api/route_register_test.go → pkg/api/routing/route_register_test.go

-package api
+package routing
 
 import (
 	"net/http"
 	"strconv"
 	"testing"
 
-	macaron "gopkg.in/macaron.v1"
+	"gopkg.in/macaron.v1"
 )
 
 type fakeRouter struct {
@@ -33,7 +33,7 @@ func (fr *fakeRouter) Get(pattern string, handlers ...macaron.Handler) *macaron.
 }
 
 func emptyHandlers(n int) []macaron.Handler {
-	res := []macaron.Handler{}
+	var res []macaron.Handler
 	for i := 1; n >= i; i++ {
 		res = append(res, emptyHandler(strconv.Itoa(i)))
 	}
@@ -138,6 +138,60 @@ func TestRouteGroupedRegister(t *testing.T) {
 		}
 	}
 }
+func TestRouteGroupInserting(t *testing.T) {
+	testTable := []route{
+		{method: http.MethodGet, pattern: "/api/", handlers: emptyHandlers(1)},
+		{method: http.MethodPost, pattern: "/api/group/endpoint", handlers: emptyHandlers(1)},
+
+		{method: http.MethodGet, pattern: "/api/group/inserted", handlers: emptyHandlers(1)},
+		{method: http.MethodDelete, pattern: "/api/inserted-endpoint", handlers: emptyHandlers(1)},
+	}
+
+	// Setup
+	rr := NewRouteRegister()
+
+	rr.Group("/api", func(api RouteRegister) {
+		api.Get("/", emptyHandler("1"))
+
+		api.Group("/group", func(group RouteRegister) {
+			group.Post("/endpoint", emptyHandler("1"))
+		})
+	})
+
+	rr.Insert("/api", func(api RouteRegister) {
+		api.Delete("/inserted-endpoint", emptyHandler("1"))
+	})
+
+	rr.Insert("/api/group", func(group RouteRegister) {
+		group.Get("/inserted", emptyHandler("1"))
+	})
+
+	fr := &fakeRouter{}
+	rr.Register(fr)
+
+	// Validation
+	if len(fr.route) != len(testTable) {
+		t.Fatalf("want %v routes, got %v", len(testTable), len(fr.route))
+	}
+
+	for i := range testTable {
+		if testTable[i].method != fr.route[i].method {
+			t.Errorf("want %s got %v", testTable[i].method, fr.route[i].method)
+		}
+
+		if testTable[i].pattern != fr.route[i].pattern {
+			t.Errorf("want %s got %v", testTable[i].pattern, fr.route[i].pattern)
+		}
+
+		if len(testTable[i].handlers) != len(fr.route[i].handlers) {
+			t.Errorf("want %d handlers got %d handlers \ntestcase: %v\nroute: %v\n",
+				len(testTable[i].handlers),
+				len(fr.route[i].handlers),
+				testTable[i],
+				fr.route[i])
+		}
+	}
+}
 
 func TestNamedMiddlewareRouteRegister(t *testing.T) {
 	testTable := []route{

pkg/cmd/grafana-server/server.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/facebookgo/inject"
+	"github.com/grafana/grafana/pkg/api/routing"
 	"github.com/grafana/grafana/pkg/bus"
 	"github.com/grafana/grafana/pkg/middleware"
 	"github.com/grafana/grafana/pkg/registry"
@@ -61,8 +62,8 @@ type GrafanaServerImpl struct {
 	shutdownReason     string
 	shutdownInProgress bool
 
-	RouteRegister api.RouteRegister `inject:""`
-	HttpServer    *api.HTTPServer   `inject:""`
+	RouteRegister routing.RouteRegister `inject:""`
+	HttpServer    *api.HTTPServer       `inject:""`
 }
 
 func (g *GrafanaServerImpl) Run() error {
@@ -75,7 +76,7 @@ func (g *GrafanaServerImpl) Run() error {
 	serviceGraph := inject.Graph{}
 	serviceGraph.Provide(&inject.Object{Value: bus.GetBus()})
 	serviceGraph.Provide(&inject.Object{Value: g.cfg})
-	serviceGraph.Provide(&inject.Object{Value: api.NewRouteRegister(middleware.RequestMetrics, middleware.RequestTracing)})
+	serviceGraph.Provide(&inject.Object{Value: routing.NewRouteRegister(middleware.RequestMetrics, middleware.RequestTracing)})
 
 	// self registered services
 	services := registry.GetServices()