Allow listing sites and filtering on org (#52)

* Allow listing unique sites and filtering on org

api/v0/api.go

@@ -33,6 +33,7 @@ type ListResponse struct {
 	Error        *v2.Error                `json:",omitempty"`
 	StaticConfig []discovery.StaticConfig `json:",omitempty"`
 	Servers      []string                 `json:",omitempty"`
+	Sites        []string                 `json:",omitempty"`
 }
 
 // Network contains IPv4 and IPv6 addresses.

handler/handler.go

@@ -331,6 +331,11 @@ func (s *Server) Delete(rw http.ResponseWriter, req *http.Request) {
 // List handler is used by monitoring to generate a list of known, active
 // hostnames previously registered with the Autojoin API.
 func (s *Server) List(rw http.ResponseWriter, req *http.Request) {
+	// Set CORS policy to allow third-party websites to use returned resources.
+	rw.Header().Set("Content-Type", "application/json")
+	rw.Header().Set("Access-Control-Allow-Origin", "*")
+	rw.Header().Set("Cache-Control", "no-store") // Prevent caching of result.
+
 	configs := []discovery.StaticConfig{}
 	resp := v0.ListResponse{}
 	hosts, ports, err := s.dnsTracker.List()
@@ -347,14 +352,21 @@ func (s *Server) List(rw http.ResponseWriter, req *http.Request) {
 		return
 	}
 
+	org := req.URL.Query().Get("org")
 	format := req.URL.Query().Get("format")
+	sites := map[string]bool{}
 
 	// Create a prometheus StaticConfig for each known host.
 	for i := range hosts {
 		h, err := host.Parse(hosts[i])
 		if err != nil {
 			continue
 		}
+		if org != "" && org != h.Org {
+			// Skip hosts that are not part of the given org.
+			continue
+		}
+		sites[h.Site] = true
 		if format == "script-exporter" {
 			// NOTE: do not assign any ports for script exporter.
 			ports[i] = []string{""}
@@ -396,6 +408,11 @@ func (s *Server) List(rw http.ResponseWriter, req *http.Request) {
 	case "servers":
 		resp.Servers = hosts
 		results = resp
+	case "sites":
+		for k := range sites {
+			resp.Sites = append(resp.Sites, k)
+		}
+		results = resp
 	default:
 		// NOTE: default format is not valid for prometheus StaticConfig format.
 		resp.StaticConfig = configs

handler/handler_test.go

@@ -591,6 +591,28 @@ func TestServer_List(t *testing.T) {
 			wantCode:   http.StatusOK,
 			wantLength: 1,
 		},
+		{
+			name:   "success-sites",
+			params: "?format=sites&org=foo",
+			lister: &fakeStatusTracker{
+				nodes: []string{"ndt-lga3356-040e9f4b.mlab.autojoin.measurement-lab.org"},
+				ports: [][]string{{"9990"}},
+			},
+			wantCode:   http.StatusOK,
+			wantLength: 0,
+		},
+		{
+			name:   "success-one-site-two-nodes",
+			params: "?format=sites&org=mlab",
+			lister: &fakeStatusTracker{
+				nodes: []string{
+					"ndt-lga3356-040e9f4b.mlab.autojoin.measurement-lab.org",
+					"ndt-lga3356-abcdef12.mlab.autojoin.measurement-lab.org"},
+				ports: [][]string{{"9990"}, {"9990"}},
+			},
+			wantCode:   http.StatusOK,
+			wantLength: 1,
+		},
 		{
 			name:   "success-script-exporter",
 			params: "?format=script-exporter&service=ndt7_client_byos",
@@ -634,6 +656,10 @@ func TestServer_List(t *testing.T) {
 				resp := v0.ListResponse{}
 				err = json.Unmarshal(raw, &resp)
 				length = len(resp.Servers)
+			} else if strings.Contains(tt.params, "sites") {
+				resp := v0.ListResponse{}
+				err = json.Unmarshal(raw, &resp)
+				length = len(resp.Sites)
 			} else {
 				resp := v0.ListResponse{}
 				err = json.Unmarshal(raw, &resp)