From 75b58d0784a5de752c19956292654023ff0ce49f Mon Sep 17 00:00:00 2001
From: Johan Siebens <johan.siebens@gmail.com>
Date: Fri, 29 Dec 2023 14:47:11 +0100
Subject: [PATCH] feat: add query feature endpoint for 'serve' support

---
 internal/handlers/query_feature.go | 70 ++++++++++++++++++++++++++++++
 internal/server/server.go          |  2 +
 2 files changed, 72 insertions(+)
 create mode 100644 internal/handlers/query_feature.go

diff --git a/internal/handlers/query_feature.go b/internal/handlers/query_feature.go
new file mode 100644
index 00000000..46265875
--- /dev/null
+++ b/internal/handlers/query_feature.go
@@ -0,0 +1,70 @@
+package handlers
+
+import (
+	"fmt"
+	"github.com/jsiebens/ionscale/internal/bind"
+	"github.com/jsiebens/ionscale/internal/dns"
+	"github.com/jsiebens/ionscale/internal/domain"
+	"github.com/labstack/echo/v4"
+	"net/http"
+	"tailscale.com/tailcfg"
+)
+
+func NewQueryFeatureHandlers(createBinder bind.Factory, dnsProvider dns.Provider, repository domain.Repository) *QueryFeatureHandlers {
+	return &QueryFeatureHandlers{
+		createBinder: createBinder,
+		repository:   repository,
+	}
+}
+
+type QueryFeatureHandlers struct {
+	createBinder bind.Factory
+	dnsProvider  dns.Provider
+	repository   domain.Repository
+}
+
+func (h *QueryFeatureHandlers) QueryFeature(c echo.Context) error {
+	ctx := c.Request().Context()
+
+	binder, err := h.createBinder(c)
+	if err != nil {
+		return logError(err)
+	}
+
+	req := new(tailcfg.QueryFeatureRequest)
+	if err := binder.BindRequest(c, req); err != nil {
+		return logError(err)
+	}
+
+	machineKey := binder.Peer().String()
+	nodeKey := req.NodeKey.String()
+
+	resp := tailcfg.QueryFeatureResponse{}
+
+	switch req.Feature {
+	case "serve":
+		machine, err := h.repository.GetMachineByKeys(ctx, machineKey, nodeKey)
+		if err != nil {
+			return err
+		}
+
+		if machine == nil {
+			return echo.NewHTTPError(http.StatusBadRequest)
+		}
+
+		if h.dnsProvider == nil || machine.Tailnet.DNSConfig.HttpsCertsEnabled {
+			resp.Text = fmt.Sprintf(serverMessage, machine.Tailnet.Name)
+		}
+	case "funnel":
+		resp.Text = fmt.Sprintf("Sorry, ionscale has no support for feature '%s'\n", req.Feature)
+	default:
+		resp.Text = fmt.Sprintf("Unknown feature request '%s'\n", req.Feature)
+	}
+
+	return binder.WriteResponse(c, http.StatusOK, resp)
+}
+
+const serverMessage = `Enabling HTTPS is required to use Serve:
+
+  ionscale tailnets set-dns --tailnet %s --https-certs=true --magic-dns
+`
diff --git a/internal/server/server.go b/internal/server/server.go
index a230160d..82b8be0b 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -114,6 +114,7 @@ func Start(c *config.Config) error {
 		dnsHandlers := handlers.NewDNSHandlers(binder, dnsProvider)
 		idTokenHandlers := handlers.NewIDTokenHandlers(binder, c, repository)
 		sshActionHandlers := handlers.NewSSHActionHandlers(binder, c, repository)
+		queryFeatureHandlers := handlers.NewQueryFeatureHandlers(binder, dnsProvider, repository)
 
 		e := echo.New()
 		e.Use(EchoMetrics(p), EchoLogger(httpLogger), EchoErrorHandler(), EchoRecover())
@@ -124,6 +125,7 @@ func Start(c *config.Config) error {
 		e.GET("/machine/ssh/action/:src_machine_id/to/:dst_machine_id", sshActionHandlers.StartAuth)
 		e.GET("/machine/ssh/action/:src_machine_id/to/:dst_machine_id/:check_period", sshActionHandlers.StartAuth)
 		e.GET("/machine/ssh/action/check/:key", sshActionHandlers.CheckAuth)
+		e.POST("/machine/feature/query", queryFeatureHandlers.QueryFeature)
 
 		return e
 	}