Generic-based internal HTTP API (#2626)

* Generic-based internal HTTP API (tested out on a few endpoints in the federation API)

* Add `PerformInvite`

* More tweaks

* Fix metric name

* Fix LookupStateIDs

* Lots of changes to clients

* Some serverside stuff

* Some error handling

* Use paths as metric names

* Revert "Use paths as metric names"

This reverts commit a9323a6a343f5ce6461a2e5bd570fe06465f1b15.

* Namespace metric names

* Remove duplicate entry

* Remove another duplicate entry

* Tweak error handling

* Some more tweaks

* Update error behaviour

* Some more error tweaking

* Fix API path for `PerformDeleteKeys`

* Fix another path

* Tweak federation client proxying

* Fix another path

* Don't return typed nils

* Some more tweaks, not that it makes any difference

* Tweak federation client proxying

* Maybe fix the key backup test

1 files changed, 20 insertions, 26 deletions

diff --git a/userapi/internal/api.go b/userapi/internal/api.go
index 422eb076..78b226d4 100644
--- a/userapi/internal/api.go
+++ b/userapi/internal/api.go
@@ -192,7 +192,9 @@ func (a *UserInternalAPI) PerformDeviceDeletion(ctx context.Context, req *api.Pe
 		deleteReq.KeyIDs = append(deleteReq.KeyIDs, gomatrixserverlib.KeyID(keyID))
 	}
 	deleteRes := &keyapi.PerformDeleteKeysResponse{}
-	a.KeyAPI.PerformDeleteKeys(ctx, deleteReq, deleteRes)
+	if err := a.KeyAPI.PerformDeleteKeys(ctx, deleteReq, deleteRes); err != nil {
+		return err
+	}
 	if err := deleteRes.Error; err != nil {
 		return fmt.Errorf("a.KeyAPI.PerformDeleteKeys: %w", err)
 	}
@@ -211,10 +213,12 @@ func (a *UserInternalAPI) deviceListUpdate(userID string, deviceIDs []string) er
 	}
 
 	var uploadRes keyapi.PerformUploadKeysResponse
-	a.KeyAPI.PerformUploadKeys(context.Background(), &keyapi.PerformUploadKeysRequest{
+	if err := a.KeyAPI.PerformUploadKeys(context.Background(), &keyapi.PerformUploadKeysRequest{
 		UserID:     userID,
 		DeviceKeys: deviceKeys,
-	}, &uploadRes)
+	}, &uploadRes); err != nil {
+		return err
+	}
 	if uploadRes.Error != nil {
 		return fmt.Errorf("failed to delete device keys: %v", uploadRes.Error)
 	}
@@ -268,7 +272,7 @@ func (a *UserInternalAPI) PerformDeviceUpdate(ctx context.Context, req *api.Perf
 	if req.DisplayName != nil && dev.DisplayName != *req.DisplayName {
 		// display name has changed: update the device key
 		var uploadRes keyapi.PerformUploadKeysResponse
-		a.KeyAPI.PerformUploadKeys(context.Background(), &keyapi.PerformUploadKeysRequest{
+		if err := a.KeyAPI.PerformUploadKeys(context.Background(), &keyapi.PerformUploadKeysRequest{
 			UserID: req.RequestingUserID,
 			DeviceKeys: []keyapi.DeviceKeys{
 				{
@@ -279,7 +283,9 @@ func (a *UserInternalAPI) PerformDeviceUpdate(ctx context.Context, req *api.Perf
 				},
 			},
 			OnlyDisplayNameUpdates: true,
-		}, &uploadRes)
+		}, &uploadRes); err != nil {
+			return err
+		}
 		if uploadRes.Error != nil {
 			return fmt.Errorf("failed to update device key display name: %v", uploadRes.Error)
 		}
@@ -479,7 +485,9 @@ func (a *UserInternalAPI) PerformAccountDeactivation(ctx context.Context, req *a
 		UserID: fmt.Sprintf("@%s:%s", req.Localpart, a.ServerName),
 	}
 	evacuateRes := &rsapi.PerformAdminEvacuateUserResponse{}
-	a.RSAPI.PerformAdminEvacuateUser(ctx, evacuateReq, evacuateRes)
+	if err := a.RSAPI.PerformAdminEvacuateUser(ctx, evacuateReq, evacuateRes); err != nil {
+		return err
+	}
 	if err := evacuateRes.Error; err != nil {
 		logrus.WithError(err).Errorf("Failed to evacuate user after account deactivation")
 	}
@@ -538,9 +546,6 @@ func (a *UserInternalAPI) PerformKeyBackup(ctx context.Context, req *api.Perform
 		if req.Version == "" {
 			res.BadInput = true
 			res.Error = "must specify a version to delete"
-			if res.Error != "" {
-				return fmt.Errorf(res.Error)
-			}
 			return nil
 		}
 		exists, err := a.DB.DeleteKeyBackup(ctx, req.UserID, req.Version)
@@ -549,9 +554,6 @@ func (a *UserInternalAPI) PerformKeyBackup(ctx context.Context, req *api.Perform
 		}
 		res.Exists = exists
 		res.Version = req.Version
-		if res.Error != "" {
-			return fmt.Errorf(res.Error)
-		}
 		return nil
 	}
 	// Create metadata
@@ -562,9 +564,6 @@ func (a *UserInternalAPI) PerformKeyBackup(ctx context.Context, req *api.Perform
 		}
 		res.Exists = err == nil
 		res.Version = version
-		if res.Error != "" {
-			return fmt.Errorf(res.Error)
-		}
 		return nil
 	}
 	// Update metadata
@@ -575,16 +574,10 @@ func (a *UserInternalAPI) PerformKeyBackup(ctx context.Context, req *api.Perform
 		}
 		res.Exists = err == nil
 		res.Version = req.Version
-		if res.Error != "" {
-			return fmt.Errorf(res.Error)
-		}
 		return nil
 	}
 	// Upload Keys for a specific version metadata
 	a.uploadBackupKeys(ctx, req, res)
-	if res.Error != "" {
-		return fmt.Errorf(res.Error)
-	}
 	return nil
 }
 
@@ -627,16 +620,16 @@ func (a *UserInternalAPI) uploadBackupKeys(ctx context.Context, req *api.Perform
 	res.KeyETag = etag
 }
 
-func (a *UserInternalAPI) QueryKeyBackup(ctx context.Context, req *api.QueryKeyBackupRequest, res *api.QueryKeyBackupResponse) {
+func (a *UserInternalAPI) QueryKeyBackup(ctx context.Context, req *api.QueryKeyBackupRequest, res *api.QueryKeyBackupResponse) error {
 	version, algorithm, authData, etag, deleted, err := a.DB.GetKeyBackup(ctx, req.UserID, req.Version)
 	res.Version = version
 	if err != nil {
 		if err == sql.ErrNoRows {
 			res.Exists = false
-			return
+			return nil
 		}
 		res.Error = fmt.Sprintf("failed to query key backup: %s", err)
-		return
+		return nil
 	}
 	res.Algorithm = algorithm
 	res.AuthData = authData
@@ -648,15 +641,16 @@ func (a *UserInternalAPI) QueryKeyBackup(ctx context.Context, req *api.QueryKeyB
 		if err != nil {
 			res.Error = fmt.Sprintf("failed to count keys: %s", err)
 		}
-		return
+		return nil
 	}
 
 	result, err := a.DB.GetBackupKeys(ctx, version, req.UserID, req.KeysForRoomID, req.KeysForSessionID)
 	if err != nil {
 		res.Error = fmt.Sprintf("failed to query keys: %s", err)
-		return
+		return nil
 	}
 	res.Keys = result
+	return nil
 }
 
 func (a *UserInternalAPI) QueryNotifications(ctx context.Context, req *api.QueryNotificationsRequest, res *api.QueryNotificationsResponse) error {