fix: better UX when attempting to turn off MDM on an offline host (#21770)

> Related issue: #20868

# Checklist for submitter

If some of the following don't apply, delete the relevant line.

<!-- Note that API documentation changes are now addressed by the
product design team. -->

- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/Committing-Changes.md#changes-files)
for more information.
- [x] Manual QA for all new/changed functionality

changes/20868-turn-off-mdm

@@ -0,0 +1 @@
+- Improves the UX of turning off MDM on an offline host (endpoint doesn't error anymore)

frontend/pages/hosts/details/HostDetailsPage/modals/UnenrollMdmModal/UnenrollMdmModal.tsx

@@ -25,11 +25,15 @@ const UnenrollMdmModal = ({ hostId, onClose }: IUnenrollMdmModalProps) => {
     setRequestState("unenrolling");
     try {
       await mdmAPI.unenrollHostFromMdm(hostId, 5000);
-      renderFlash("success", "Successfully turned off MDM.");
+      renderFlash(
+        "success",
+        "Turning off MDM or will turn off when the host comes online."
+      );
       onClose();
     } catch (unenrollMdmError: unknown) {
+      renderFlash("error", "Couldn't turn off MDM. Please try again.");
       console.log(unenrollMdmError);
-      setRequestState("error");
+      onClose();
     }
   };
 

server/service/apple_mdm.go

@@ -1570,47 +1570,17 @@ func (svc *Service) EnqueueMDMAppleCommandRemoveEnrollmentProfile(ctx context.Co
 		return ctxerr.Wrap(ctx, err, "logging activity for mdm apple remove profile command")
 	}
 
-	return svc.pollResultMDMAppleCommandRemoveEnrollmentProfile(ctx, cmdUUID, h.UUID, info.Platform)
-}
-
-func (svc *Service) pollResultMDMAppleCommandRemoveEnrollmentProfile(ctx context.Context, cmdUUID string, deviceID string, platform string) error {
-	ctx, cancelFn := context.WithDeadline(ctx, time.Now().Add(5*time.Second))
-	ticker := time.NewTicker(300 * time.Millisecond)
-	defer func() {
-		ticker.Stop()
-		cancelFn()
-	}()
-
-	for {
-		select {
-		case <-ctx.Done():
-			// time out after 5 seconds
-			return fleet.MDMAppleCommandTimeoutError{}
-		case <-ticker.C:
-			nanoEnroll, err := svc.ds.GetNanoMDMEnrollment(ctx, deviceID)
-			if err != nil {
-				level.Error(svc.logger).Log("err", "get nanomdm enrollment status", "details", err, "id", deviceID, "command_uuid", cmdUUID)
-				return err
-			}
-			if nanoEnroll != nil && nanoEnroll.Enabled {
-				// check again on the next tick
-				continue
-			}
-			// success, mdm enrollment is no longer enabled for the device
-			level.Info(svc.logger).Log("msg", "mdm disabled for device", "id", deviceID, "command_uuid", cmdUUID)
-
-			mdmLifecycle := mdmlifecycle.New(svc.ds, svc.logger)
-			err = mdmLifecycle.Do(ctx, mdmlifecycle.HostOptions{
-				Action:   mdmlifecycle.HostActionTurnOff,
-				Platform: platform,
-				UUID:     deviceID,
-			})
-			if err != nil {
-				return err
-			}
-			return nil
-		}
+	mdmLifecycle := mdmlifecycle.New(svc.ds, svc.logger)
+	err = mdmLifecycle.Do(ctx, mdmlifecycle.HostOptions{
+		Action:   mdmlifecycle.HostActionTurnOff,
+		Platform: info.Platform,
+		UUID:     h.UUID,
+	})
+	if err != nil {
+		return ctxerr.Wrap(ctx, err, "running turn off action in mdm lifecycle")
 	}
+
+	return nil
 }
 
 type mdmAppleGetInstallerRequest struct {

server/service/integration_mdm_test.go

@@ -1378,8 +1378,8 @@ func (s *integrationMDMTestSuite) TestMDMAppleUnenroll() {
 	// 3 profiles added + 1 profile with fleetd configuration + 1 root CA config
 	require.Len(t, *hostResp.Host.MDM.Profiles, 5)
 
-	// try to unenroll the host, fails since the host doesn't respond
-	s.Do("DELETE", fmt.Sprintf("/api/latest/fleet/hosts/%d/mdm", h.ID), nil, http.StatusGatewayTimeout)
+	// returns success, but this is effectively a no-op because the host isn't enrolled yet.
+	s.Do("DELETE", fmt.Sprintf("/api/latest/fleet/hosts/%d/mdm", h.ID), nil, http.StatusOK)
 
 	// we're going to modify this mock, make sure we restore its default
 	originalPushMock := s.pushProvider.PushFunc