Add app capabilities to /api endpoint

app/api_report_test.go

@@ -14,7 +14,7 @@ import (
 
 func topologyServer() *httptest.Server {
 	router := mux.NewRouter().SkipClean(true)
-	app.RegisterTopologyRoutes(router, app.StaticCollector(fixture.Report))
+	app.RegisterTopologyRoutes(router, app.StaticCollector(fixture.Report), map[string]bool{"foo_capability": true})
 	return httptest.NewServer(router)
 }
 

app/api_topologies_test.go

@@ -189,7 +189,7 @@ func TestAPITopologyAddsKubernetes(t *testing.T) {
 	router := mux.NewRouter()
 	c := app.NewCollector(1 * time.Minute)
 	app.RegisterReportPostHandler(c, router)
-	app.RegisterTopologyRoutes(router, c)
+	app.RegisterTopologyRoutes(router, c, map[string]bool{"foo_capability": true})
 	ts := httptest.NewServer(router)
 	defer ts.Close()
 

app/router.go

@@ -90,10 +90,10 @@ func gzipHandler(h http.HandlerFunc) http.HandlerFunc {
 }
 
 // RegisterTopologyRoutes registers the various topology routes with a http mux.
-func RegisterTopologyRoutes(router *mux.Router, r Reporter) {
+func RegisterTopologyRoutes(router *mux.Router, r Reporter, capabilities map[string]bool) {
 	get := router.Methods("GET").Subrouter()
 	get.HandleFunc("/api",
-		gzipHandler(requestContextDecorator(apiHandler(r))))
+		gzipHandler(requestContextDecorator(apiHandler(r, capabilities))))
 	get.HandleFunc("/api/topology",
 		gzipHandler(requestContextDecorator(topologyRegistry.makeTopologyList(r))))
 	get.
@@ -177,7 +177,7 @@ func NewVersion(version, downloadURL string) {
 	}
 }
 
-func apiHandler(rep Reporter) CtxHandlerFunc {
+func apiHandler(rep Reporter, capabilities map[string]bool) CtxHandlerFunc {
 	return func(ctx context.Context, w http.ResponseWriter, r *http.Request) {
 		report, err := rep.Report(ctx)
 		if err != nil {
@@ -187,11 +187,12 @@ func apiHandler(rep Reporter) CtxHandlerFunc {
 		newVersion.Lock()
 		defer newVersion.Unlock()
 		respondWith(w, http.StatusOK, xfer.Details{
-			ID:         UniqueID,
-			Version:    Version,
-			Hostname:   hostname.Get(),
-			Plugins:    report.Plugins,
-			NewVersion: newVersion.NewVersionInfo,
+			ID:           UniqueID,
+			Version:      Version,
+			Hostname:     hostname.Get(),
+			Plugins:      report.Plugins,
+			Capabilities: capabilities,
+			NewVersion:   newVersion.NewVersionInfo,
 		})
 	}
 }

common/xfer/constants.go

@@ -14,12 +14,15 @@ const (
 	ScopeProbeVersionHeader = "X-Scope-Probe-Version"
 )
 
+const ReportPersistenceCapability = "report_persistence"
+
 // Details are some generic details that can be fetched from /api
 type Details struct {
-	ID       string      `json:"id"`
-	Version  string      `json:"version"`
-	Hostname string      `json:"hostname"`
-	Plugins  PluginSpecs `json:"plugins,omitempty"`
+	ID           string          `json:"id"`
+	Version      string          `json:"version"`
+	Hostname     string          `json:"hostname"`
+	Plugins      PluginSpecs     `json:"plugins,omitempty"`
+	Capabilities map[string]bool `json:"capabilities,omitempty"`
 
 	NewVersion *NewVersionInfo `json:"newVersion,omitempty"`
 }

prog/app.go

@@ -19,6 +19,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/tylerb/graceful"
 	"github.com/weaveworks/go-checkpoint"
+	"github.com/weaveworks/scope/common/xfer"
 	"github.com/weaveworks/weave/common"
 
 	billing "github.com/weaveworks/billing-client"
@@ -50,7 +51,7 @@ func init() {
 }
 
 // Router creates the mux for all the various app components.
-func router(collector app.Collector, controlRouter app.ControlRouter, pipeRouter app.PipeRouter, externalUI bool) http.Handler {
+func router(collector app.Collector, controlRouter app.ControlRouter, pipeRouter app.PipeRouter, externalUI bool, capabilities map[string]bool) http.Handler {
 	router := mux.NewRouter().SkipClean(true)
 
 	// We pull in the http.DefaultServeMux to get the pprof routes
@@ -60,7 +61,7 @@ func router(collector app.Collector, controlRouter app.ControlRouter, pipeRouter
 	app.RegisterReportPostHandler(collector, router)
 	app.RegisterControlRoutes(router, controlRouter)
 	app.RegisterPipeRoutes(router, pipeRouter)
-	app.RegisterTopologyRoutes(router, collector)
+	app.RegisterTopologyRoutes(router, collector, capabilities)
 
 	uiHandler := http.FileServer(GetFS(externalUI))
 	router.PathPrefix("/ui").Name("static").Handler(
@@ -294,7 +295,10 @@ func appMain(flags appFlags) {
 		}
 	}
 
-	handler := router(collector, controlRouter, pipeRouter, flags.externalUI)
+	capabilities := map[string]bool{
+		xfer.ReportPersistenceCapability: flags.s3URL != "local",
+	}
+	handler := router(collector, controlRouter, pipeRouter, flags.externalUI, capabilities)
 	if flags.logHTTP {
 		handler = middleware.Log{
 			LogRequestHeaders: flags.logHTTPHeaders,