Storage: Add system users service (#57767)

* Storage: Add access for reporting

* reporting upload user per org

* add some basic comments

* Move reporting storage to enterprise

* add comments

Co-authored-by: Artur Wierzbicki <artur.wierzbicki@grafana.com>

pkg/services/store/system_users_test.go

@@ -0,0 +1,63 @@
+package store
+
+import (
+	"testing"
+
+	"github.com/grafana/grafana/pkg/infra/filestorage"
+	"github.com/grafana/grafana/pkg/services/user"
+	"github.com/stretchr/testify/require"
+)
+
+const admin SystemUserType = "storageAdmin"
+
+func TestRetrievalOfNotInitializedOrg(t *testing.T) {
+	service := setupSystemUsers()
+
+	orgID := int64(1)
+	user, err := service.GetUser(admin, orgID)
+	require.NoError(t, err)
+
+	require.Equal(t, string(admin), user.Login)
+	require.Equal(t, orgID, user.OrgID)
+
+	userFromSubsequentCall, err := service.GetUser(admin, orgID)
+	require.NoError(t, err)
+	require.Same(t, user, userFromSubsequentCall)
+}
+
+func TestRetrievalOfFilterForInitializedUser(t *testing.T) {
+	service := setupSystemUsers()
+
+	orgID := int64(1)
+	reportsAdminUser, err := service.GetUser(admin, orgID)
+	require.NoError(t, err)
+
+	filter, err := service.GetFilter(reportsAdminUser)
+	require.NoError(t, err)
+	require.NotNil(t, filter)
+}
+
+func TestRetrievalOfFilterForNotInitializedUser(t *testing.T) {
+	service := setupSystemUsers()
+
+	orgID := int64(1)
+
+	filter, err := service.GetFilter(&user.SignedInUser{
+		OrgID: orgID,
+		Login: string(admin),
+	})
+	require.Error(t, err)
+	require.Nil(t, filter)
+}
+
+func setupSystemUsers() SystemUsers {
+	service := ProvideSystemUsersService()
+
+	service.RegisterUser(admin, func() map[string]filestorage.PathFilter {
+		return map[string]filestorage.PathFilter{
+			ActionFilesRead: denyAllPathFilter,
+		}
+	})
+
+	return service
+}