-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Systemd facilities (Socket activation, Notify)
--   
--   A module for Systemd facilities.
@package systemd
@version 2.0.0


-- | Implementation of Systemd facilities to create and manage daemons.
--   
--   This module contains socket activation and notify tools. See
--   
--   <ul>
--   
--   <li><a>http://0pointer.de/blog/projects/socket-activation.html</a></li>
--   
--   <li><a>http://www.freedesktop.org/software/systemd/man/systemd.socket.html</a></li>
--   
--   <li><a>http://www.freedesktop.org/software/systemd/man/systemd.service.html</a></li>
--   </ul>
--   
--   Example:
--   
--   <pre>
--   import Control.Monad(forever)
--   import System.Systemd.Daemon(notifyWatchdog)
--   
--   main :: IO ()
--   main = forever $ do
--           functionThatMayHang
--           notifyWatchdog
--   </pre>
--   
--   If you use the service described as below, Systemd will restart your
--   program each time the watchdog fail to notify itself under 60 sec.
--   
--   <pre>
--   [Unit]
--   Description=MyDaemon
--   
--   [Service]
--   Type=simple
--   TimeoutStartSec=0
--   ExecStart=AbsolutePathToMyExecutable
--   WatchdogSec=60
--   Restart=on-failure
--   
--   [Install]
--   WantedBy=multi-user.target
--   </pre>
module System.Systemd.Daemon

-- | Notify systemd about an event
--   
--   After notifying systemd the <a>Bool</a> parameter specify if the
--   environnement shall be unset (Further call to notify will fail)
--   
--   The <a>String</a> is the event to pass
--   
--   Returns <a>Nothing</a> if the program was not started with systemd or
--   that the environnement was previously unset
notify :: Bool -> String -> IO (Maybe ())

-- | Same as <a>notify</a> but send along a socket to be stored
--   
--   It is up to the caller to properly set the message (i.e: do not forget
--   to set FDSTORE=1)
notifyWithFD :: Bool -> String -> Socket -> IO (Maybe ())

-- | Notify systemd to store a socket for us.
--   
--   To be used along <a>getActivatedSockets</a> during a restart
--   
--   Usefull for zero downtime restart
storeFd :: Socket -> IO (Maybe ())

-- | Notify systemd to store a socket for us and specify a name.
--   
--   To be used along <a>getActivatedSocketsWithNames</a> during a restart
--   
--   Usefull for zero downtime restart
storeFdWithName :: Socket -> String -> IO (Maybe ())

-- | Notify the watchdog that the program is still alive
notifyWatchdog :: IO (Maybe ())

-- | Notify the systemd that the program is ready
notifyReady :: IO (Maybe ())

-- | Notify systemd of the PID of the program (for after a fork)
notifyPID :: CPid -> IO (Maybe ())

-- | Notify systemd of an <a>Errno</a> error
notifyErrno :: Errno -> IO (Maybe ())

-- | Notify systemd of the status of the program.
--   
--   An arbitrary <a>String</a> can be passed
notifyStatus :: String -> IO (Maybe ())

-- | Notify systemd of a DBUS error like.
--   
--   Correct formatting of the <a>String</a> is left to the caller
notifyBusError :: String -> IO (Maybe ())

-- | Notify systemd that the service is reloading its configuration
notifyReloading :: IO (Maybe ())

-- | Notify systemd that the service is beginning its shutdown
notifyStopping :: IO (Maybe ())

-- | Return a list of activated sockets, if the program was started with
--   socket activation.
--   
--   The sockets are in the same order as in the associated
--   <tt>.socket</tt> file. The sockets will have their family, type, and
--   status set appropriately.
--   
--   Returns <a>Nothing</a> in systems without socket activation (or when
--   the program was not socket activated).
getActivatedSockets :: IO (Maybe [Socket])

-- | Same as <a>getActivatedSockets</a> but return also the names
--   associated with those sockets if <a>storeFdWithName</a> was used or
--   specified in the <tt>.socket</tt> file.
--   
--   IF <a>storeFd</a> was used to transmit the socket to systemd, the name
--   will be a generic one (i.e: usally "stored")
getActivatedSocketsWithNames :: IO (Maybe [(Socket, String)])

-- | Unset all environnement variable related to Systemd.
--   
--   Calls to <a>notify</a> like and <a>getActivatedSockets</a> functions
--   will return <a>Nothing</a> after that
unsetEnvironnement :: IO ()