feat: add endpoint to get listening ports in agent (#4260)

agent/statsendpoint.go

@@ -0,0 +1,49 @@
+package agent
+
+import (
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/go-chi/chi"
+
+	"github.com/coder/coder/coderd/httpapi"
+	"github.com/coder/coder/codersdk"
+)
+
+func (*agent) statisticsHandler() http.Handler {
+	r := chi.NewRouter()
+	r.Get("/", func(rw http.ResponseWriter, r *http.Request) {
+		httpapi.Write(r.Context(), rw, http.StatusOK, codersdk.Response{
+			Message: "Hello from the agent!",
+		})
+	})
+
+	lp := &listeningPortsHandler{}
+	r.Get("/api/v0/listening-ports", lp.handler)
+
+	return r
+}
+
+type listeningPortsHandler struct {
+	mut   sync.Mutex
+	ports []codersdk.ListeningPort
+	mtime time.Time
+}
+
+// handler returns a list of listening ports. This is tested by coderd's
+// TestWorkspaceAgentListeningPorts test.
+func (lp *listeningPortsHandler) handler(rw http.ResponseWriter, r *http.Request) {
+	ports, err := lp.getListeningPorts()
+	if err != nil {
+		httpapi.Write(r.Context(), rw, http.StatusInternalServerError, codersdk.Response{
+			Message: "Could not scan for listening ports.",
+			Detail:  err.Error(),
+		})
+		return
+	}
+
+	httpapi.Write(r.Context(), rw, http.StatusOK, codersdk.ListeningPortsResponse{
+		Ports: ports,
+	})
+}