diff --git a/README.md b/README.md --- a/README.md +++ b/README.md @@ -1,6 +1,6 @@ `hdaemonize` ================= -[![Build Status](https://travis-ci.org/greydot/hdaemonize.svg?branch=master)](https://travis-ci.org/greydot/hdaemonize) +[![Build Status](https://travis-ci.org/unprolix/hdaemonize.svg?branch=master)](https://travis-ci.org/unprolix/hdaemonize) `hdaemonize` is a simple library that hides some of the complexities of writing UNIX daemons in Haskell. @@ -9,7 +9,7 @@ ----------- The latest version is available (BSD license) at -[GitHub](https://github.com/greydot/hdaemonize). +[GitHub](https://github.com/unprolix/hdaemonize). Using ------- @@ -60,14 +60,27 @@ # mydaemon stop # mydaemon restart -Finally, `mydaemon` drops privileges. By default it changes the -effective user and group ids to those of the `daemon` user, but it -prefers to use those of `mydaemon`, if present. +Finally, if configured to do so, `mydaemon` drops privileges by +changing its effective user/group ID. (If no user/group ID are +specified, it will continue execution as the original user and group.) +Note that if you wish to parse your own commandline arguments, you can +replace invocation of the `serviced` function with `serviced'`. This +requires specification of an `Operation` which indicates whether the +daemon should be started, stopped, restarted, or whether its status +should be queried. Changelog --------- +* 0.5.6 + * Add `serviced'` function and `Operation` (`Start`, `Stop`, etc.) to allow invocation separated from commandline + * Only attempt to change effective user/group ID when explicitly specified. + * Do not attempt to set user or group to the daemon's name in the absence of a specified user or group. + +* 0.5.5 + * Fix a bug where hdaemonize fails when user or group "daemon" is absent + * 0.5.4 * Update to use hsyslog == 5. @@ -93,6 +106,8 @@ Authors ------- +Jeremy Bornstein + Lana Black Anton Tayanovskyy . diff --git a/System/Posix/Daemonize.hs b/System/Posix/Daemonize.hs --- a/System/Posix/Daemonize.hs +++ b/System/Posix/Daemonize.hs @@ -4,7 +4,7 @@ -- * Simple daemonization daemonize, -- * Building system services - serviced, CreateDaemon(..), simpleDaemon, + serviced, serviced', CreateDaemon(..), simpleDaemon, Operation(..), -- * Intradaemon utilities fatalError, exitCleanly, -- * Logging utilities @@ -40,11 +40,13 @@ import Data.Maybe (isNothing, fromMaybe, fromJust) import System.Environment import System.Exit -import System.Posix +import System.Posix hiding (Start, Stop) import System.Posix.Syslog (Priority(..), Facility(Daemon), Option, withSyslog) import qualified System.Posix.Syslog as Log import System.FilePath.Posix (joinPath) +data Operation = Start | Stop | Restart | Status deriving (Eq, Show) + syslog :: Priority -> ByteString -> IO () syslog pri msg = unsafeUseAsCStringLen msg (Log.syslog (Just Daemon) pri) @@ -121,11 +123,26 @@ serviced :: CreateDaemon a -> IO () serviced daemon = do + args <- getArgs + + let mOperation :: Maybe Operation + mOperation = case args of + ("start" : _) -> Just Start + ("stop" : _) -> Just Stop + ("restart" : _) -> Just Restart + ("status" : _) -> Just Status + _ -> Nothing + + if isNothing mOperation + then getProgName >>= \pname -> putStrLn $ "usage: " ++ pname ++ " {start|stop|status|restart}" + else serviced' daemon $ fromJust mOperation + +serviced' :: CreateDaemon a -> Operation -> IO () +serviced' daemon operation = do systemName <- getProgName let daemon' = daemon { name = if isNothing (name daemon) then Just systemName else name daemon } - args <- getArgs - process daemon' args + process daemon' operation where program' daemon = withSyslog (fromJust (name daemon)) (syslogOptions daemon) Daemon $ do let log = syslog Notice @@ -135,12 +152,12 @@ dropPrivileges daemon forever $ program daemon privVal - process daemon ["start"] = pidExists daemon >>= f where + process daemon Start = pidExists daemon >>= f where f True = do error "PID file exists. Process already running?" exitImmediately (ExitFailure 1) f False = daemonize (program' daemon) - process daemon ["stop"] = + process daemon Stop = do pid <- pidRead daemon case pid of Nothing -> pass @@ -152,10 +169,10 @@ `finally` removeLink (pidFile daemon) - process daemon ["restart"] = do process daemon ["stop"] - process daemon ["start"] + process daemon Restart = do process daemon Stop + process daemon Start - process daemon ["status"] = pidExists daemon >>= f where + process daemon Status = pidExists daemon >>= f where f True = do pid <- pidRead daemon case pid of @@ -167,9 +184,6 @@ else putStrLn $ fromJust (name daemon) ++ " is not running, but pidfile is remaining." f False = putStrLn $ fromJust (name daemon) ++ " is not running." - process _ _ = - getProgName >>= \pname -> putStrLn $ "usage: " ++ pname ++ " {start|stop|status|restart}" - -- Wait 'secs' seconds for the process to exit, checking -- for liveness once a second. If still alive send sigKILL. wait :: Maybe Int -> CPid -> IO () @@ -298,30 +312,27 @@ f (Left _) = Nothing f (Right uid) = Just uid +-- only drop privileges if a user is specified dropPrivileges :: CreateDaemon a -> IO () -dropPrivileges daemon = - do let targetUser = fromJust $ asum [ user daemon - , name daemon - , Just "daemon" - ] - targetGroup = fromJust $ asum [ group daemon - , name daemon - , Just "daemon" - ] - mud <- getUserID targetUser - mgd <- getGroupID targetGroup - u <- case mud of - Nothing -> do syslog Error "Privilege drop failure, no suitable user." - exitImmediately (ExitFailure 1) - undefined - Just ud -> pure ud - g <- case mgd of - Nothing -> do syslog Error "Privilege drop failure, no suitable group." - exitImmediately (ExitFailure 1) - undefined - Just gd -> pure gd - setGroupID g - setUserID u +dropPrivileges daemon = do + case group daemon of + Nothing -> pure () + Just targetGroup -> do + mud <- getGroupID targetGroup + case mud of + Nothing -> do syslog Error "Privilege drop failure, could not identify specified group." + exitImmediately (ExitFailure 1) + undefined + Just gd -> setGroupID gd + case user daemon of + Nothing -> pure () + Just targetUser -> do + mud <- getUserID targetUser + case mud of + Nothing -> do syslog Error "Privilege drop failure, could not identify specified user." + exitImmediately (ExitFailure 1) + undefined + Just ud -> setUserID ud pidFile:: CreateDaemon a -> String pidFile daemon = joinPath [dir, fromJust (name daemon) ++ ".pid"] diff --git a/hdaemonize.cabal b/hdaemonize.cabal --- a/hdaemonize.cabal +++ b/hdaemonize.cabal @@ -1,21 +1,22 @@ Name: hdaemonize -Version: 0.5.5 +Version: 0.5.6 Cabal-Version: >= 1.6 License: BSD3 License-file: LICENSE -Author: Anton Tayanovskyy, Fred Ross -Maintainer: Lana Black -Homepage: http://github.com/greydot/hdaemonize +Author: Anton Tayanovskyy, Fred Ross, Lana Black +Maintainer: Jeremy Bornstein +Homepage: http://github.com/unprolix/hdaemonize Category: System Synopsis: Library to handle the details of writing daemons for UNIX -Description: Provides two functions that help writing better UNIX daemons, - daemonize and serviced: daemonize does what a daemon should do - (forking and closing descriptors), while serviced does that and - more (syslog interface, PID file writing, start-stop-restart - command line handling, dropping privileges). +Description: Provides functions that help writing better UNIX daemons, + daemonize and serviced/serviced': daemonize does what + a daemon should do (forking and closing descriptors), + while serviced does that and more (syslog interface, + PID file writing, start-stop-restart command line + handling, dropping privileges). Build-Type: Simple Extra-Source-Files: README.md -Tested-With: GHC == 7.10.3, GHC == 8.0.2, GHC == 8.2.2 +Tested-With: GHC == 8.2.2, GHC == 8.4.4, GHC == 8.6.4, GHC == 8.6.5 Library Build-Depends: base >= 4 && < 5 @@ -33,4 +34,4 @@ source-repository head type: git - location: https://github.com/greydot/hdaemonize.git + location: https://github.com/unprolix/hdaemonize.git