WeaveTagger becomes Weave, both Reporter & Tagger

probe/endpoint/nat.go

@@ -149,7 +149,6 @@ func applyNAT(rpt report.Report, scope string) error {
 func conntrackModulePresent() bool {
 	f, err := os.Open(modules)
 	if err != nil {
-		//log.Printf("conntrack error: %v", err) // /proc doesn't exist on Darwin
 		return false
 	}
 	defer f.Close()

probe/main.go

@@ -75,25 +75,13 @@ func main() {
 	defer publisher.Close()
 
 	var (
-		hostName = hostname()
-		hostID   = hostName // TODO: we should sanitize the hostname
-	)
-
-	var (
-		weaveTagger  *overlay.WeaveTagger
+		hostName     = hostname()
+		hostID       = hostName // TODO: we should sanitize the hostname
+		taggers      = []Tagger{newTopologyTagger(), host.NewTagger(hostID)}
+		reporters    = []Reporter{host.NewReporter(hostID, hostName), endpoint.NewReporter(hostID, hostName, *spyProcs)}
 		processCache *process.CachingWalker
 	)
 
-	taggers := []Tagger{
-		newTopologyTagger(),
-		host.NewTagger(hostID),
-	}
-
-	reporters := []Reporter{
-		host.NewReporter(hostID, hostName),
-		endpoint.NewReporter(hostID, hostName, *spyProcs),
-	}
-
 	// TODO provide an alternate implementation for Darwin.
 	if runtime.GOOS == linux {
 		processCache = process.NewCachingWalker(process.NewWalker(*procRoot))
@@ -116,12 +104,12 @@ func main() {
 	}
 
 	if *weaveRouterAddr != "" {
-		var err error
-		weaveTagger, err = overlay.NewWeaveTagger(*weaveRouterAddr)
+		weave, err := overlay.NewWeave(*weaveRouterAddr)
 		if err != nil {
 			log.Fatalf("failed to start Weave tagger: %v", err)
 		}
-		taggers = append(taggers, weaveTagger)
+		taggers = append(taggers, weave)
+		reporters = append(reporters, weave)
 	}
 
 	log.Printf("listening on %s", *listen)
@@ -157,10 +145,6 @@ func main() {
 					r.Merge(newReport)
 				}
 
-				if weaveTagger != nil {
-					r.Overlay.Merge(weaveTagger.OverlayTopology())
-				}
-
 				r = Apply(r, taggers)
 
 			case <-quit:

probe/overlay/weave.go

@@ -21,39 +21,40 @@ const (
 	WeavePeerNickName = "weave_peer_nick_name"
 )
 
-// WeaveTagger represents a single Weave router, presumably on the same host
-// as the probe. It can produce an Overlay topology, and in theory can tag
-// existing topologies with foreign keys to overlay -- though I'm not sure
-// what that would look like in practice right now.
-type WeaveTagger struct {
+// Weave represents a single Weave router, presumably on the same host
+// as the probe. It is both a Reporter and a Tagger: it produces an Overlay
+// topology, and (in theory) can tag existing topologies with foreign keys to
+// overlay -- though I'm not sure what that would look like in practice right
+// now.
+type Weave struct {
 	url string
 }
 
-// NewWeaveTagger returns a new Weave tagger based on the Weave router at
+// NewWeave returns a new Weave tagger based on the Weave router at
 // address. The address should be an IP or FQDN, no port.
-func NewWeaveTagger(weaveRouterAddress string) (*WeaveTagger, error) {
+func NewWeave(weaveRouterAddress string) (*Weave, error) {
 	s, err := sanitize("http://", 6784, "/status-json")(weaveRouterAddress)
 	if err != nil {
 		return nil, err
 	}
-	return &WeaveTagger{s}, nil
+	return &Weave{s}, nil
 }
 
 // Tag implements Tagger.
-func (t WeaveTagger) Tag(r report.Report) (report.Report, error) {
+func (w Weave) Tag(r report.Report) (report.Report, error) {
 	// The status-json endpoint doesn't return any link information, so
 	// there's nothing to tag, yet.
 	return r, nil
 }
 
-// OverlayTopology produces an overlay topology from the Weave router.
-func (t WeaveTagger) OverlayTopology() report.Topology {
-	topology := report.NewTopology()
+// Report implements Reporter.
+func (w Weave) Report() (report.Report, error) {
+	r := report.MakeReport()
 
-	resp, err := http.Get(t.url)
+	resp, err := http.Get(w.url)
 	if err != nil {
 		log.Printf("Weave Tagger: %v", err)
-		return topology
+		return r, err
 	}
 	defer resp.Body.Close()
 
@@ -65,17 +66,16 @@ func (t WeaveTagger) OverlayTopology() report.Topology {
 	}
 	if err := json.NewDecoder(resp.Body).Decode(&status); err != nil {
 		log.Printf("Weave Tagger: %v", err)
-		return topology
+		return r, err
 	}
 
 	for _, peer := range status.Peers {
-		topology.NodeMetadatas[report.MakeOverlayNodeID(peer.Name)] = report.NodeMetadata{
+		r.Overlay.NodeMetadatas[report.MakeOverlayNodeID(peer.Name)] = report.NodeMetadata{
 			WeavePeerName:     peer.Name,
 			WeavePeerNickName: peer.NickName,
 		}
 	}
-
-	return topology
+	return r, nil
 }
 
 func sanitize(scheme string, port int, path string) func(string) (string, error) {

probe/overlay/weave_test.go

@@ -9,17 +9,22 @@ import (
 
 	"github.com/weaveworks/scope/probe/overlay"
 	"github.com/weaveworks/scope/report"
+	"github.com/weaveworks/scope/test"
 )
 
 func TestWeaveTaggerOverlayTopology(t *testing.T) {
 	s := httptest.NewServer(http.HandlerFunc(mockWeaveRouter))
 	defer s.Close()
 
-	w, err := overlay.NewWeaveTagger(s.URL)
+	w, err := overlay.NewWeave(s.URL)
 	if err != nil {
 		t.Fatal(err)
 	}
 
+	have, err := w.Report()
+	if err != nil {
+		t.Fatal(err)
+	}
 	if want, have := (report.Topology{
 		Adjacency:     report.Adjacency{},
 		EdgeMetadatas: report.EdgeMetadatas{},
@@ -29,8 +34,8 @@ func TestWeaveTaggerOverlayTopology(t *testing.T) {
 				overlay.WeavePeerNickName: mockWeavePeerNickName,
 			},
 		},
-	}), w.OverlayTopology(); !reflect.DeepEqual(want, have) {
-		t.Errorf("want\n\t%#v, have\n\t%#v", want, have)
+	}), have.Overlay; !reflect.DeepEqual(want, have) {
+		t.Error(test.Diff(want, have))
 	}
 }
 
@@ -46,6 +51,6 @@ func mockWeaveRouter(w http.ResponseWriter, r *http.Request) {
 			"NickName": mockWeavePeerNickName,
 		}},
 	}); err != nil {
-		println(err.Error())
+		panic(err)
 	}
 }