--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libervia/web/server/tasks/task.py	Fri Jun 02 16:49:28 2023 +0200
@@ -0,0 +1,90 @@
+#!/usr/bin/env python3
+
+# Libervia: a Salut à Toi frontend
+# Copyright (C) 2011-2021 Jérôme Poisson <goffi@goffi.org>
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+from twisted.python.procutils import which
+from libervia.backend.core.log import getLogger
+from libervia.backend.tools.common import async_process
+from libervia.backend.core import exceptions
+from libervia.backend.core.i18n import _
+from typing import Optional
+
+log = getLogger(__name__)
+
+
+class Task:
+    """Handle tasks of a Libervia site"""
+    # can be "stop" or "continue"
+    ON_ERROR: str = "stop"
+    LOG_OUTPUT: bool = True
+    # list of directories to check for restarting this task
+    # Task.on_dir_event will be called if it exists, otherwise
+    # the task will be run and Task.start will be called
+    WATCH_DIRS: Optional[list] = None
+    # list of task names which must be prepared/started before this one
+    AFTER: Optional[list] = None
+
+    def __init__(self, manager, task_name):
+        self.manager = manager
+        self.name = task_name
+
+    @property
+    def host(self):
+        return self.manager.host
+
+    @property
+    def resource(self):
+        return self.manager.resource
+
+    @property
+    def site_path(self):
+        return self.manager.site_path
+
+    @property
+    def build_path(self):
+        """path where generated files will be build for this site"""
+        return self.manager.build_path
+
+    def config_get(self, key, default=None, value_type=None):
+        return self.host.config_get(self.resource, key=key, default=default,
+                                   value_type=value_type)
+
+    @property
+    def site_name(self):
+        return self.resource.site_name
+
+    def find_command(self, name, *args):
+        """Find full path of a shell command
+
+        @param name(unicode): name of the command to find
+        @param *args(unicode): extra names the command may have
+        @return (unicode): full path of the command
+        @raise exceptions.NotFound: can't find this command
+        """
+        names = (name,) + args
+        for n in names:
+            try:
+                cmd_path = which(n)[0]
+            except IndexError:
+                pass
+            else:
+                return cmd_path
+        raise exceptions.NotFound(_(
+            "Can't find {name} command, did you install it?").format(name=name))
+
+    def runCommand(self, command, *args, **kwargs):
+        kwargs['verbose'] = self.LOG_OUTPUT
+        return async_process.CommandProtocol.run(command, *args, **kwargs)