proxy: Add an interface for user role assignment

This moves the lookup and the creation of the users' role assignemt out
of the user backend into its own interface. This makes the user backend
a bit simpler and allows to provide different implemenation for the user
role assignment more easily.

services/proxy/pkg/user/backend/backend.go

@@ -2,13 +2,10 @@ package backend
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 
 	gateway "github.com/cs3org/go-cs3apis/cs3/gateway/v1beta1"
 	cs3 "github.com/cs3org/go-cs3apis/cs3/identity/user/v1beta1"
-	types "github.com/cs3org/go-cs3apis/cs3/types/v1beta1"
-	settingssvc "github.com/owncloud/ocis/v2/protogen/gen/ocis/services/settings/v0"
 	"google.golang.org/grpc"
 )
 
@@ -26,7 +23,6 @@ var (
 // UserBackend allows the proxy to retrieve users from different user-backends (accounts-service, CS3)
 type UserBackend interface {
 	GetUserByClaims(ctx context.Context, claim, value string) (*cs3.User, string, error)
-	GetUserRoles(ctx context.Context, user *cs3.User) (*cs3.User, error)
 	Authenticate(ctx context.Context, username string, password string) (*cs3.User, string, error)
 	CreateUserFromClaims(ctx context.Context, claims map[string]interface{}) (*cs3.User, error)
 }
@@ -35,34 +31,3 @@ type UserBackend interface {
 type RevaAuthenticator interface {
 	Authenticate(ctx context.Context, in *gateway.AuthenticateRequest, opts ...grpc.CallOption) (*gateway.AuthenticateResponse, error)
 }
-
-// loadRolesIDs returns the role-ids assigned to an user
-func loadRolesIDs(ctx context.Context, opaqueUserID string, rs settingssvc.RoleService) ([]string, error) {
-	req := &settingssvc.ListRoleAssignmentsRequest{AccountUuid: opaqueUserID}
-	assignmentResponse, err := rs.ListRoleAssignments(ctx, req)
-
-	if err != nil {
-		return nil, err
-	}
-
-	roleIDs := make([]string, 0)
-
-	for _, assignment := range assignmentResponse.Assignments {
-		roleIDs = append(roleIDs, assignment.RoleId)
-	}
-
-	return roleIDs, nil
-}
-
-// encodeRoleIDs encoded the given role id's in to reva-specific format to be able to mint a token from them
-func encodeRoleIDs(roleIDs []string) (*types.OpaqueEntry, error) {
-	roleIDsJSON, err := json.Marshal(roleIDs)
-	if err != nil {
-		return nil, err
-	}
-
-	return &types.OpaqueEntry{
-		Decoder: "json",
-		Value:   roleIDsJSON,
-	}, nil
-}