recipe_modules/daemonizer/api.py

# Copyright 2020 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

from recipe_engine import recipe_api

from contextlib import contextmanager


class DaemonizerApi(recipe_api.RecipeApi):
    """DaemonizerApi provides support for daemonizing processes."""

    def __call__(self, *args, **kwargs):
        """Return a git command step."""
        name = kwargs.pop("name", "daemonize " + args[0])
        return self.m.step(name, [self.script] + list(args), **kwargs)

    @property
    def script(self):
        return self.resource("daemonizer.py")

    def start(self, pidfile, cmd, **kwargs):
        return self("--pidfile", pidfile, *cmd, **kwargs)

    def stop(self, pidfile, **kwargs):
        return self("--action", "stop", "--pidfile", pidfile, **kwargs)

    def restart(self, pidfile, cmd, **kwargs):
        return self("--action", "restart", "--pidfile", pidfile, *cmd, **kwargs)

    @contextmanager
    def daemonize(self, cmd, **kwargs):
        pidfile = self.m.path.mkstemp(prefix="pid")
        try:
            self.start(pidfile, cmd, **kwargs)
            yield
        finally:
            self.stop(pidfile, **kwargs)