From a6cf9b3d8d6f03b5a998c624843176e06c2a34ba Mon Sep 17 00:00:00 2001
From: Roberto Dip <dip.jesusr@gmail.com>
Date: Thu, 9 Jun 2022 10:17:55 -0300
Subject: [PATCH] add endpoint in devices API to query for api features (#6152)

Related to #6063, this adds a new device API to get an object with boolean values that we can use as feature flags to manage backwards compatibility in Fleet Desktop.
---
 server/fleet/app.go                     |  5 +++++
 server/service/devices.go               | 23 +++++++++++++++++++++++
 server/service/handler.go               |  1 +
 server/service/integration_core_test.go |  8 ++++++++
 4 files changed, 37 insertions(+)

diff --git a/server/fleet/app.go b/server/fleet/app.go
index 54f6cea8da..44ce16b50f 100644
--- a/server/fleet/app.go
+++ b/server/fleet/app.go
@@ -435,3 +435,8 @@ type KafkaRESTConfig struct {
 	ResultTopic string `json:"result_topic"`
 	ProxyHost   string `json:"proxyhost"`
 }
+
+// DeviceAPIFeatures specifies a list of features supported
+// by the current API version. Each field in the struct is
+// meant to be a boolean value.
+type DeviceAPIFeatures struct{}
diff --git a/server/service/devices.go b/server/service/devices.go
index db36774ceb..fa9110eabd 100644
--- a/server/service/devices.go
+++ b/server/service/devices.go
@@ -214,3 +214,26 @@ func (svc *Service) ListDevicePolicies(ctx context.Context, host *fleet.Host) ([
 
 	return nil, fleet.ErrMissingLicense
 }
+
+////////////////////////////////////////////////////////////////////////////////
+// Device API features
+////////////////////////////////////////////////////////////////////////////////
+
+type deviceAPIFeaturesRequest struct {
+	Token string `url:"token"`
+}
+
+func (r *deviceAPIFeaturesRequest) deviceAuthToken() string {
+	return r.Token
+}
+
+type deviceAPIFeaturesResponse struct {
+	Err      error `json:"error,omitempty"`
+	Features fleet.DeviceAPIFeatures
+}
+
+func (r deviceAPIFeaturesResponse) error() error { return r.Err }
+
+func deviceAPIFeaturesEndpoint(ctx context.Context, request interface{}, svc fleet.Service) (interface{}, error) {
+	return deviceAPIFeaturesResponse{Features: fleet.DeviceAPIFeatures{}}, nil
+}
diff --git a/server/service/handler.go b/server/service/handler.go
index 203293e5da..5d3d9b90ff 100644
--- a/server/service/handler.go
+++ b/server/service/handler.go
@@ -396,6 +396,7 @@ func attachFleetAPIRoutes(r *mux.Router, svc fleet.Service, config config.FleetC
 	de.GET("/api/_version_/fleet/device/{token}/device_mapping", listDeviceHostDeviceMappingEndpoint, listDeviceHostDeviceMappingRequest{})
 	de.GET("/api/_version_/fleet/device/{token}/macadmins", getDeviceMacadminsDataEndpoint, getDeviceMacadminsDataRequest{})
 	de.GET("/api/_version_/fleet/device/{token}/policies", listDevicePoliciesEndpoint, listDevicePoliciesRequest{})
+	de.GET("/api/_version_/fleet/device/{token}/api_features", deviceAPIFeaturesEndpoint, deviceAPIFeaturesRequest{})
 
 	// host-authenticated endpoints
 	he := newHostAuthenticatedEndpointer(svc, logger, opts, r, apiVersions...)
diff --git a/server/service/integration_core_test.go b/server/service/integration_core_test.go
index a70db25dd4..e83ecfb4ff 100644
--- a/server/service/integration_core_test.go
+++ b/server/service/integration_core_test.go
@@ -4624,6 +4624,14 @@ func (s *integrationTestSuite) TestDeviceAuthenticatedEndpoints() {
 	json.NewDecoder(res.Body).Decode(&getHostResp)
 	res.Body.Close()
 	require.Nil(t, listPoliciesResp.Policies)
+
+	// get list of api features
+	apiFeaturesResp := deviceAPIFeaturesResponse{}
+	res = s.DoRawNoAuth("GET", "/api/latest/fleet/device/"+token+"/api_features", nil, http.StatusOK)
+	json.NewDecoder(res.Body).Decode(&apiFeaturesResp)
+	res.Body.Close()
+	require.Nil(t, apiFeaturesResp.Err)
+	require.NotNil(t, apiFeaturesResp.Features)
 }
 
 func (s *integrationTestSuite) TestModifyUser() {