root / src / Ganeti / Daemon.hs @ 670e954a
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1 | 6ec7a50e | Iustin Pop | {-| Implementation of the generic daemon functionality. |
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2 | 6ec7a50e | Iustin Pop | |
3 | 6ec7a50e | Iustin Pop | -} |
4 | 6ec7a50e | Iustin Pop | |
5 | 6ec7a50e | Iustin Pop | {- |
6 | 6ec7a50e | Iustin Pop | |
7 | 6ec7a50e | Iustin Pop | Copyright (C) 2011, 2012 Google Inc. |
8 | 6ec7a50e | Iustin Pop | |
9 | 6ec7a50e | Iustin Pop | This program is free software; you can redistribute it and/or modify |
10 | 6ec7a50e | Iustin Pop | it under the terms of the GNU General Public License as published by |
11 | 6ec7a50e | Iustin Pop | the Free Software Foundation; either version 2 of the License, or |
12 | 6ec7a50e | Iustin Pop | (at your option) any later version. |
13 | 6ec7a50e | Iustin Pop | |
14 | 6ec7a50e | Iustin Pop | This program is distributed in the hope that it will be useful, but |
15 | 6ec7a50e | Iustin Pop | WITHOUT ANY WARRANTY; without even the implied warranty of |
16 | 6ec7a50e | Iustin Pop | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
17 | 6ec7a50e | Iustin Pop | General Public License for more details. |
18 | 6ec7a50e | Iustin Pop | |
19 | 6ec7a50e | Iustin Pop | You should have received a copy of the GNU General Public License |
20 | 6ec7a50e | Iustin Pop | along with this program; if not, write to the Free Software |
21 | 6ec7a50e | Iustin Pop | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
22 | 6ec7a50e | Iustin Pop | 02110-1301, USA. |
23 | 6ec7a50e | Iustin Pop | |
24 | 6ec7a50e | Iustin Pop | -} |
25 | 6ec7a50e | Iustin Pop | |
26 | 6ec7a50e | Iustin Pop | module Ganeti.Daemon |
27 | 6ec7a50e | Iustin Pop | ( DaemonOptions(..) |
28 | 6ec7a50e | Iustin Pop | , OptType |
29 | 2ac2e420 | Iustin Pop | , CheckFn |
30 | 2ac2e420 | Iustin Pop | , PrepFn |
31 | 2ac2e420 | Iustin Pop | , MainFn |
32 | 6ec7a50e | Iustin Pop | , defaultOptions |
33 | 6ec7a50e | Iustin Pop | , oShowHelp |
34 | 6ec7a50e | Iustin Pop | , oShowVer |
35 | 6ec7a50e | Iustin Pop | , oNoDaemonize |
36 | 6ec7a50e | Iustin Pop | , oNoUserChecks |
37 | 6ec7a50e | Iustin Pop | , oDebug |
38 | 6ec7a50e | Iustin Pop | , oPort |
39 | 152e05e1 | Iustin Pop | , oBindAddress |
40 | b714ff89 | Iustin Pop | , oSyslogUsage |
41 | 6ec7a50e | Iustin Pop | , parseArgs |
42 | 152e05e1 | Iustin Pop | , parseAddress |
43 | 0d0ac025 | Iustin Pop | , cleanupSocket |
44 | e14b84e9 | Iustin Pop | , describeError |
45 | 6ec7a50e | Iustin Pop | , genericMain |
46 | 6ec7a50e | Iustin Pop | ) where |
47 | 6ec7a50e | Iustin Pop | |
48 | 79ac58fa | Iustin Pop | import Control.Exception |
49 | 6ec7a50e | Iustin Pop | import Control.Monad |
50 | 0c28bee1 | Iustin Pop | import Data.Maybe (fromMaybe) |
51 | 6ec7a50e | Iustin Pop | import Data.Word |
52 | 0c28bee1 | Iustin Pop | import GHC.IO.Handle (hDuplicateTo) |
53 | 670e954a | Thomas Thrainer | import Network.BSD (getHostName) |
54 | 152e05e1 | Iustin Pop | import qualified Network.Socket as Socket |
55 | 6ec7a50e | Iustin Pop | import System.Console.GetOpt |
56 | 6ec7a50e | Iustin Pop | import System.Exit |
57 | 6ec7a50e | Iustin Pop | import System.Environment |
58 | 6ec7a50e | Iustin Pop | import System.IO |
59 | e14b84e9 | Iustin Pop | import System.IO.Error (isDoesNotExistError, modifyIOError, annotateIOError) |
60 | 6ec7a50e | Iustin Pop | import System.Posix.Directory |
61 | 6ec7a50e | Iustin Pop | import System.Posix.Files |
62 | 6ec7a50e | Iustin Pop | import System.Posix.IO |
63 | 6ec7a50e | Iustin Pop | import System.Posix.Process |
64 | 6ec7a50e | Iustin Pop | import System.Posix.Types |
65 | 36691f08 | Iustin Pop | import System.Posix.Signals |
66 | 6ec7a50e | Iustin Pop | |
67 | 51000365 | Iustin Pop | import Ganeti.Common as Common |
68 | 6ec7a50e | Iustin Pop | import Ganeti.Logging |
69 | 6ec7a50e | Iustin Pop | import Ganeti.Runtime |
70 | 6ec7a50e | Iustin Pop | import Ganeti.BasicTypes |
71 | 26d62e4c | Iustin Pop | import Ganeti.Utils |
72 | 6ec7a50e | Iustin Pop | import qualified Ganeti.Constants as C |
73 | 152e05e1 | Iustin Pop | import qualified Ganeti.Ssconf as Ssconf |
74 | 6ec7a50e | Iustin Pop | |
75 | 0c28bee1 | Iustin Pop | -- * Constants |
76 | 0c28bee1 | Iustin Pop | |
77 | 0c28bee1 | Iustin Pop | -- | \/dev\/null path. |
78 | 0c28bee1 | Iustin Pop | devNull :: FilePath |
79 | 0c28bee1 | Iustin Pop | devNull = "/dev/null" |
80 | 0c28bee1 | Iustin Pop | |
81 | b9097468 | Iustin Pop | -- | Error message prefix, used in two separate paths (when forking |
82 | b9097468 | Iustin Pop | -- and when not). |
83 | b9097468 | Iustin Pop | daemonStartupErr :: String -> String |
84 | b9097468 | Iustin Pop | daemonStartupErr = ("Error when starting the daemon process: " ++) |
85 | b9097468 | Iustin Pop | |
86 | 6ec7a50e | Iustin Pop | -- * Data types |
87 | 6ec7a50e | Iustin Pop | |
88 | 6ec7a50e | Iustin Pop | -- | Command line options structure. |
89 | 6ec7a50e | Iustin Pop | data DaemonOptions = DaemonOptions |
90 | 6ec7a50e | Iustin Pop | { optShowHelp :: Bool -- ^ Just show the help |
91 | 6ec7a50e | Iustin Pop | , optShowVer :: Bool -- ^ Just show the program version |
92 | 097ad7ee | Iustin Pop | , optShowComp :: Bool -- ^ Just show the completion info |
93 | 6ec7a50e | Iustin Pop | , optDaemonize :: Bool -- ^ Whether to daemonize or not |
94 | 6ec7a50e | Iustin Pop | , optPort :: Maybe Word16 -- ^ Override for the network port |
95 | 6ec7a50e | Iustin Pop | , optDebug :: Bool -- ^ Enable debug messages |
96 | 6ec7a50e | Iustin Pop | , optNoUserChecks :: Bool -- ^ Ignore user checks |
97 | 152e05e1 | Iustin Pop | , optBindAddress :: Maybe String -- ^ Override for the bind address |
98 | b714ff89 | Iustin Pop | , optSyslogUsage :: Maybe SyslogUsage -- ^ Override for Syslog usage |
99 | 6ec7a50e | Iustin Pop | } |
100 | 6ec7a50e | Iustin Pop | |
101 | 6ec7a50e | Iustin Pop | -- | Default values for the command line options. |
102 | 6ec7a50e | Iustin Pop | defaultOptions :: DaemonOptions |
103 | 6ec7a50e | Iustin Pop | defaultOptions = DaemonOptions |
104 | 6ec7a50e | Iustin Pop | { optShowHelp = False |
105 | 6ec7a50e | Iustin Pop | , optShowVer = False |
106 | 097ad7ee | Iustin Pop | , optShowComp = False |
107 | 6ec7a50e | Iustin Pop | , optDaemonize = True |
108 | 6ec7a50e | Iustin Pop | , optPort = Nothing |
109 | 6ec7a50e | Iustin Pop | , optDebug = False |
110 | 6ec7a50e | Iustin Pop | , optNoUserChecks = False |
111 | 152e05e1 | Iustin Pop | , optBindAddress = Nothing |
112 | b714ff89 | Iustin Pop | , optSyslogUsage = Nothing |
113 | 6ec7a50e | Iustin Pop | } |
114 | 6ec7a50e | Iustin Pop | |
115 | 51000365 | Iustin Pop | instance StandardOptions DaemonOptions where |
116 | 51000365 | Iustin Pop | helpRequested = optShowHelp |
117 | 51000365 | Iustin Pop | verRequested = optShowVer |
118 | 097ad7ee | Iustin Pop | compRequested = optShowComp |
119 | 5b11f8db | Iustin Pop | requestHelp o = o { optShowHelp = True } |
120 | 5b11f8db | Iustin Pop | requestVer o = o { optShowVer = True } |
121 | 097ad7ee | Iustin Pop | requestComp o = o { optShowComp = True } |
122 | 51000365 | Iustin Pop | |
123 | 6ec7a50e | Iustin Pop | -- | Abrreviation for the option type. |
124 | 51000365 | Iustin Pop | type OptType = GenericOptType DaemonOptions |
125 | 6ec7a50e | Iustin Pop | |
126 | 2ac2e420 | Iustin Pop | -- | Check function type. |
127 | 2ac2e420 | Iustin Pop | type CheckFn a = DaemonOptions -> IO (Either ExitCode a) |
128 | 2ac2e420 | Iustin Pop | |
129 | 2ac2e420 | Iustin Pop | -- | Prepare function type. |
130 | 2ac2e420 | Iustin Pop | type PrepFn a b = DaemonOptions -> a -> IO b |
131 | 2ac2e420 | Iustin Pop | |
132 | 2ac2e420 | Iustin Pop | -- | Main execution function type. |
133 | 2ac2e420 | Iustin Pop | type MainFn a b = DaemonOptions -> a -> b -> IO () |
134 | 2ac2e420 | Iustin Pop | |
135 | 6ec7a50e | Iustin Pop | -- * Command line options |
136 | 6ec7a50e | Iustin Pop | |
137 | 6ec7a50e | Iustin Pop | oNoDaemonize :: OptType |
138 | ce207617 | Iustin Pop | oNoDaemonize = |
139 | ce207617 | Iustin Pop | (Option "f" ["foreground"] |
140 | ce207617 | Iustin Pop | (NoArg (\ opts -> Ok opts { optDaemonize = False})) |
141 | ce207617 | Iustin Pop | "Don't detach from the current terminal", |
142 | ce207617 | Iustin Pop | OptComplNone) |
143 | 6ec7a50e | Iustin Pop | |
144 | 6ec7a50e | Iustin Pop | oDebug :: OptType |
145 | ce207617 | Iustin Pop | oDebug = |
146 | ce207617 | Iustin Pop | (Option "d" ["debug"] |
147 | ce207617 | Iustin Pop | (NoArg (\ opts -> Ok opts { optDebug = True })) |
148 | ce207617 | Iustin Pop | "Enable debug messages", |
149 | ce207617 | Iustin Pop | OptComplNone) |
150 | 6ec7a50e | Iustin Pop | |
151 | 6ec7a50e | Iustin Pop | oNoUserChecks :: OptType |
152 | ce207617 | Iustin Pop | oNoUserChecks = |
153 | ce207617 | Iustin Pop | (Option "" ["no-user-checks"] |
154 | ce207617 | Iustin Pop | (NoArg (\ opts -> Ok opts { optNoUserChecks = True })) |
155 | ce207617 | Iustin Pop | "Ignore user checks", |
156 | ce207617 | Iustin Pop | OptComplNone) |
157 | 6ec7a50e | Iustin Pop | |
158 | 6ec7a50e | Iustin Pop | oPort :: Int -> OptType |
159 | ce207617 | Iustin Pop | oPort def = |
160 | ce207617 | Iustin Pop | (Option "p" ["port"] |
161 | ce207617 | Iustin Pop | (reqWithConversion (tryRead "reading port") |
162 | ce207617 | Iustin Pop | (\port opts -> Ok opts { optPort = Just port }) "PORT") |
163 | ce207617 | Iustin Pop | ("Network port (default: " ++ show def ++ ")"), |
164 | ecebe9f6 | Iustin Pop | OptComplInteger) |
165 | 6ec7a50e | Iustin Pop | |
166 | 152e05e1 | Iustin Pop | oBindAddress :: OptType |
167 | ce207617 | Iustin Pop | oBindAddress = |
168 | ce207617 | Iustin Pop | (Option "b" ["bind"] |
169 | ce207617 | Iustin Pop | (ReqArg (\addr opts -> Ok opts { optBindAddress = Just addr }) |
170 | ce207617 | Iustin Pop | "ADDR") |
171 | ce207617 | Iustin Pop | "Bind address (default depends on cluster configuration)", |
172 | ce207617 | Iustin Pop | OptComplInetAddr) |
173 | 152e05e1 | Iustin Pop | |
174 | b714ff89 | Iustin Pop | oSyslogUsage :: OptType |
175 | ce207617 | Iustin Pop | oSyslogUsage = |
176 | ce207617 | Iustin Pop | (Option "" ["syslog"] |
177 | ce207617 | Iustin Pop | (reqWithConversion syslogUsageFromRaw |
178 | ce207617 | Iustin Pop | (\su opts -> Ok opts { optSyslogUsage = Just su }) |
179 | ce207617 | Iustin Pop | "SYSLOG") |
180 | ce207617 | Iustin Pop | ("Enable logging to syslog (except debug \ |
181 | ce207617 | Iustin Pop | \messages); one of 'no', 'yes' or 'only' [" ++ C.syslogUsage ++ |
182 | ce207617 | Iustin Pop | "]"), |
183 | ce207617 | Iustin Pop | OptComplChoices ["yes", "no", "only"]) |
184 | b714ff89 | Iustin Pop | |
185 | 42834645 | Iustin Pop | -- | Generic options. |
186 | 42834645 | Iustin Pop | genericOpts :: [OptType] |
187 | 42834645 | Iustin Pop | genericOpts = [ oShowHelp |
188 | 42834645 | Iustin Pop | , oShowVer |
189 | 097ad7ee | Iustin Pop | , oShowComp |
190 | 42834645 | Iustin Pop | ] |
191 | 42834645 | Iustin Pop | |
192 | 7413b229 | Iustin Pop | -- | Annotates and transforms IOErrors into a Result type. This can be |
193 | 7413b229 | Iustin Pop | -- used in the error handler argument to 'catch', for example. |
194 | 7413b229 | Iustin Pop | ioErrorToResult :: String -> IOError -> IO (Result a) |
195 | 7413b229 | Iustin Pop | ioErrorToResult description exc = |
196 | 7413b229 | Iustin Pop | return . Bad $ description ++ ": " ++ show exc |
197 | 7413b229 | Iustin Pop | |
198 | 6ec7a50e | Iustin Pop | -- | Small wrapper over getArgs and 'parseOpts'. |
199 | 6ec7a50e | Iustin Pop | parseArgs :: String -> [OptType] -> IO (DaemonOptions, [String]) |
200 | 6ec7a50e | Iustin Pop | parseArgs cmd options = do |
201 | 6ec7a50e | Iustin Pop | cmd_args <- getArgs |
202 | 22278fa7 | Iustin Pop | parseOpts defaultOptions cmd_args cmd (options ++ genericOpts) [] |
203 | 6ec7a50e | Iustin Pop | |
204 | 6ec7a50e | Iustin Pop | -- * Daemon-related functions |
205 | a4c0fe1e | Iustin Pop | |
206 | 6ec7a50e | Iustin Pop | -- | PID file mode. |
207 | 6ec7a50e | Iustin Pop | pidFileMode :: FileMode |
208 | 6ec7a50e | Iustin Pop | pidFileMode = unionFileModes ownerReadMode ownerWriteMode |
209 | 6ec7a50e | Iustin Pop | |
210 | a4c0fe1e | Iustin Pop | -- | PID file open flags. |
211 | a4c0fe1e | Iustin Pop | pidFileFlags :: OpenFileFlags |
212 | a4c0fe1e | Iustin Pop | pidFileFlags = defaultFileFlags { noctty = True, trunc = False } |
213 | a4c0fe1e | Iustin Pop | |
214 | 6ec7a50e | Iustin Pop | -- | Writes a PID file and locks it. |
215 | e14b84e9 | Iustin Pop | writePidFile :: FilePath -> IO Fd |
216 | e14b84e9 | Iustin Pop | writePidFile path = do |
217 | a4c0fe1e | Iustin Pop | fd <- openFd path ReadWrite (Just pidFileMode) pidFileFlags |
218 | 6ec7a50e | Iustin Pop | setLock fd (WriteLock, AbsoluteSeek, 0, 0) |
219 | 6ec7a50e | Iustin Pop | my_pid <- getProcessID |
220 | 6ec7a50e | Iustin Pop | _ <- fdWrite fd (show my_pid ++ "\n") |
221 | 6ec7a50e | Iustin Pop | return fd |
222 | 6ec7a50e | Iustin Pop | |
223 | 0d0ac025 | Iustin Pop | -- | Helper function to ensure a socket doesn't exist. Should only be |
224 | 0d0ac025 | Iustin Pop | -- called once we have locked the pid file successfully. |
225 | 0d0ac025 | Iustin Pop | cleanupSocket :: FilePath -> IO () |
226 | 5b11f8db | Iustin Pop | cleanupSocket socketPath = |
227 | 0d0ac025 | Iustin Pop | catchJust (guard . isDoesNotExistError) (removeLink socketPath) |
228 | 0d0ac025 | Iustin Pop | (const $ return ()) |
229 | 0d0ac025 | Iustin Pop | |
230 | 6ec7a50e | Iustin Pop | -- | Sets up a daemon's environment. |
231 | 6ec7a50e | Iustin Pop | setupDaemonEnv :: FilePath -> FileMode -> IO () |
232 | 6ec7a50e | Iustin Pop | setupDaemonEnv cwd umask = do |
233 | 6ec7a50e | Iustin Pop | changeWorkingDirectory cwd |
234 | 6ec7a50e | Iustin Pop | _ <- setFileCreationMask umask |
235 | 6ec7a50e | Iustin Pop | _ <- createSession |
236 | 6ec7a50e | Iustin Pop | return () |
237 | 6ec7a50e | Iustin Pop | |
238 | 36691f08 | Iustin Pop | -- | Signal handler for reopening log files. |
239 | 36691f08 | Iustin Pop | handleSigHup :: FilePath -> IO () |
240 | 36691f08 | Iustin Pop | handleSigHup path = do |
241 | 36691f08 | Iustin Pop | setupDaemonFDs (Just path) |
242 | 36691f08 | Iustin Pop | logInfo "Reopening log files after receiving SIGHUP" |
243 | 36691f08 | Iustin Pop | |
244 | 0c28bee1 | Iustin Pop | -- | Sets up a daemon's standard file descriptors. |
245 | 0c28bee1 | Iustin Pop | setupDaemonFDs :: Maybe FilePath -> IO () |
246 | 0c28bee1 | Iustin Pop | setupDaemonFDs logfile = do |
247 | 0c28bee1 | Iustin Pop | null_in_handle <- openFile devNull ReadMode |
248 | 0c28bee1 | Iustin Pop | null_out_handle <- openFile (fromMaybe devNull logfile) AppendMode |
249 | 0c28bee1 | Iustin Pop | hDuplicateTo null_in_handle stdin |
250 | 0c28bee1 | Iustin Pop | hDuplicateTo null_out_handle stdout |
251 | 0c28bee1 | Iustin Pop | hDuplicateTo null_out_handle stderr |
252 | 0c28bee1 | Iustin Pop | hClose null_in_handle |
253 | 0c28bee1 | Iustin Pop | hClose null_out_handle |
254 | 0c28bee1 | Iustin Pop | |
255 | 152e05e1 | Iustin Pop | -- | Computes the default bind address for a given family. |
256 | 152e05e1 | Iustin Pop | defaultBindAddr :: Int -- ^ The port we want |
257 | 152e05e1 | Iustin Pop | -> Socket.Family -- ^ The cluster IP family |
258 | 152e05e1 | Iustin Pop | -> Result (Socket.Family, Socket.SockAddr) |
259 | 152e05e1 | Iustin Pop | defaultBindAddr port Socket.AF_INET = |
260 | 5b11f8db | Iustin Pop | Ok (Socket.AF_INET, |
261 | 5b11f8db | Iustin Pop | Socket.SockAddrInet (fromIntegral port) Socket.iNADDR_ANY) |
262 | 152e05e1 | Iustin Pop | defaultBindAddr port Socket.AF_INET6 = |
263 | 5b11f8db | Iustin Pop | Ok (Socket.AF_INET6, |
264 | 5b11f8db | Iustin Pop | Socket.SockAddrInet6 (fromIntegral port) 0 Socket.iN6ADDR_ANY 0) |
265 | 152e05e1 | Iustin Pop | defaultBindAddr _ fam = Bad $ "Unsupported address family: " ++ show fam |
266 | 152e05e1 | Iustin Pop | |
267 | 152e05e1 | Iustin Pop | -- | Default hints for the resolver |
268 | 152e05e1 | Iustin Pop | resolveAddrHints :: Maybe Socket.AddrInfo |
269 | 152e05e1 | Iustin Pop | resolveAddrHints = |
270 | 152e05e1 | Iustin Pop | Just Socket.defaultHints { Socket.addrFlags = [Socket.AI_NUMERICHOST, |
271 | 152e05e1 | Iustin Pop | Socket.AI_NUMERICSERV] } |
272 | 152e05e1 | Iustin Pop | |
273 | 152e05e1 | Iustin Pop | -- | Resolves a numeric address. |
274 | 152e05e1 | Iustin Pop | resolveAddr :: Int -> String -> IO (Result (Socket.Family, Socket.SockAddr)) |
275 | 152e05e1 | Iustin Pop | resolveAddr port str = do |
276 | 152e05e1 | Iustin Pop | resolved <- Socket.getAddrInfo resolveAddrHints (Just str) (Just (show port)) |
277 | 152e05e1 | Iustin Pop | return $ case resolved of |
278 | 152e05e1 | Iustin Pop | [] -> Bad "Invalid results from lookup?" |
279 | 5b11f8db | Iustin Pop | best:_ -> Ok (Socket.addrFamily best, Socket.addrAddress best) |
280 | 152e05e1 | Iustin Pop | |
281 | 152e05e1 | Iustin Pop | -- | Based on the options, compute the socket address to use for the |
282 | 152e05e1 | Iustin Pop | -- daemon. |
283 | 152e05e1 | Iustin Pop | parseAddress :: DaemonOptions -- ^ Command line options |
284 | 152e05e1 | Iustin Pop | -> Int -- ^ Default port for this daemon |
285 | 152e05e1 | Iustin Pop | -> IO (Result (Socket.Family, Socket.SockAddr)) |
286 | 152e05e1 | Iustin Pop | parseAddress opts defport = do |
287 | 152e05e1 | Iustin Pop | let port = maybe defport fromIntegral $ optPort opts |
288 | 152e05e1 | Iustin Pop | def_family <- Ssconf.getPrimaryIPFamily Nothing |
289 | 5b11f8db | Iustin Pop | case optBindAddress opts of |
290 | 5b11f8db | Iustin Pop | Nothing -> return (def_family >>= defaultBindAddr port) |
291 | b9612abb | Iustin Pop | Just saddr -> Control.Exception.catch |
292 | b9612abb | Iustin Pop | (resolveAddr port saddr) |
293 | 7413b229 | Iustin Pop | (ioErrorToResult $ "Invalid address " ++ saddr) |
294 | 152e05e1 | Iustin Pop | |
295 | 670e954a | Thomas Thrainer | -- | Environment variable to override the assumed host name of the |
296 | 670e954a | Thomas Thrainer | -- current node. |
297 | 670e954a | Thomas Thrainer | vClusterHostNameEnvVar :: String |
298 | 670e954a | Thomas Thrainer | vClusterHostNameEnvVar = "GANETI_HOSTNAME" |
299 | 670e954a | Thomas Thrainer | |
300 | 670e954a | Thomas Thrainer | -- | Returns if the current node is the master node. |
301 | 670e954a | Thomas Thrainer | isMaster :: IO Bool |
302 | 670e954a | Thomas Thrainer | isMaster = do |
303 | 670e954a | Thomas Thrainer | let ioErrorToNothing :: IOError -> IO (Maybe String) |
304 | 670e954a | Thomas Thrainer | ioErrorToNothing _ = return Nothing |
305 | 670e954a | Thomas Thrainer | vcluster_node <- Control.Exception.catch |
306 | 670e954a | Thomas Thrainer | (liftM Just (getEnv vClusterHostNameEnvVar)) |
307 | 670e954a | Thomas Thrainer | ioErrorToNothing |
308 | 670e954a | Thomas Thrainer | curNode <- case vcluster_node of |
309 | 670e954a | Thomas Thrainer | Just node_name -> return node_name |
310 | 670e954a | Thomas Thrainer | Nothing -> getHostName |
311 | 670e954a | Thomas Thrainer | masterNode <- Ssconf.getMasterNode Nothing |
312 | 670e954a | Thomas Thrainer | case masterNode of |
313 | 670e954a | Thomas Thrainer | Ok n -> return (curNode == n) |
314 | 670e954a | Thomas Thrainer | Bad _ -> return False |
315 | 670e954a | Thomas Thrainer | |
316 | 670e954a | Thomas Thrainer | -- | Ensures that the daemon runs on the right node (and exits |
317 | 670e954a | Thomas Thrainer | -- gracefully if it doesnt) |
318 | 670e954a | Thomas Thrainer | ensureNode :: GanetiDaemon -> IO () |
319 | 670e954a | Thomas Thrainer | ensureNode daemon = do |
320 | 670e954a | Thomas Thrainer | is_master <- isMaster |
321 | 670e954a | Thomas Thrainer | when (daemonOnlyOnMaster daemon && not is_master) $ do |
322 | 670e954a | Thomas Thrainer | putStrLn "Not master, exiting." |
323 | 670e954a | Thomas Thrainer | exitWith (ExitFailure C.exitNotmaster) |
324 | 670e954a | Thomas Thrainer | |
325 | e14b84e9 | Iustin Pop | -- | Run an I\/O action that might throw an I\/O error, under a |
326 | e14b84e9 | Iustin Pop | -- handler that will simply annotate and re-throw the exception. |
327 | e14b84e9 | Iustin Pop | describeError :: String -> Maybe Handle -> Maybe FilePath -> IO a -> IO a |
328 | e14b84e9 | Iustin Pop | describeError descr hndl fpath = |
329 | e14b84e9 | Iustin Pop | modifyIOError (\e -> annotateIOError e descr hndl fpath) |
330 | e14b84e9 | Iustin Pop | |
331 | e14b84e9 | Iustin Pop | -- | Run an I\/O action as a daemon. |
332 | 6ec7a50e | Iustin Pop | -- |
333 | 6ec7a50e | Iustin Pop | -- WARNING: this only works in single-threaded mode (either using the |
334 | 6ec7a50e | Iustin Pop | -- single-threaded runtime, or using the multi-threaded one but with |
335 | 6ec7a50e | Iustin Pop | -- only one OS thread, i.e. -N1). |
336 | b9097468 | Iustin Pop | daemonize :: FilePath -> (Maybe Fd -> IO ()) -> IO () |
337 | 0c28bee1 | Iustin Pop | daemonize logfile action = do |
338 | b9097468 | Iustin Pop | (rpipe, wpipe) <- createPipe |
339 | 6ec7a50e | Iustin Pop | -- first fork |
340 | 6ec7a50e | Iustin Pop | _ <- forkProcess $ do |
341 | 6ec7a50e | Iustin Pop | -- in the child |
342 | b9097468 | Iustin Pop | closeFd rpipe |
343 | 1a865afe | Iustin Pop | let wpipe' = Just wpipe |
344 | 6ec7a50e | Iustin Pop | setupDaemonEnv "/" (unionFileModes groupModes otherModes) |
345 | 1a865afe | Iustin Pop | setupDaemonFDs (Just logfile) `Control.Exception.catch` |
346 | 1a865afe | Iustin Pop | handlePrepErr False wpipe' |
347 | 36691f08 | Iustin Pop | _ <- installHandler lostConnection (Catch (handleSigHup logfile)) Nothing |
348 | b9097468 | Iustin Pop | -- second fork, launches the actual child code; standard |
349 | b9097468 | Iustin Pop | -- double-fork technique |
350 | 1a865afe | Iustin Pop | _ <- forkProcess (action wpipe') |
351 | 6ec7a50e | Iustin Pop | exitImmediately ExitSuccess |
352 | b9097468 | Iustin Pop | closeFd wpipe |
353 | b9097468 | Iustin Pop | hndl <- fdToHandle rpipe |
354 | b9097468 | Iustin Pop | errors <- hGetContents hndl |
355 | b9097468 | Iustin Pop | ecode <- if null errors |
356 | b9097468 | Iustin Pop | then return ExitSuccess |
357 | b9097468 | Iustin Pop | else do |
358 | b9097468 | Iustin Pop | hPutStrLn stderr $ daemonStartupErr errors |
359 | b9097468 | Iustin Pop | return $ ExitFailure C.exitFailure |
360 | b9097468 | Iustin Pop | exitImmediately ecode |
361 | 6ec7a50e | Iustin Pop | |
362 | 6ec7a50e | Iustin Pop | -- | Generic daemon startup. |
363 | 2ac2e420 | Iustin Pop | genericMain :: GanetiDaemon -- ^ The daemon we're running |
364 | 2ac2e420 | Iustin Pop | -> [OptType] -- ^ The available options |
365 | 2ac2e420 | Iustin Pop | -> CheckFn a -- ^ Check function |
366 | 2ac2e420 | Iustin Pop | -> PrepFn a b -- ^ Prepare function |
367 | 2ac2e420 | Iustin Pop | -> MainFn a b -- ^ Execution function |
368 | 2ac2e420 | Iustin Pop | -> IO () |
369 | 2ac2e420 | Iustin Pop | genericMain daemon options check_fn prep_fn exec_fn = do |
370 | 6ec7a50e | Iustin Pop | let progname = daemonName daemon |
371 | 670e954a | Thomas Thrainer | |
372 | 6ec7a50e | Iustin Pop | (opts, args) <- parseArgs progname options |
373 | 6ec7a50e | Iustin Pop | |
374 | 670e954a | Thomas Thrainer | ensureNode daemon |
375 | 670e954a | Thomas Thrainer | |
376 | 88a10df5 | Iustin Pop | exitUnless (null args) "This program doesn't take any arguments" |
377 | 6ec7a50e | Iustin Pop | |
378 | 6ec7a50e | Iustin Pop | unless (optNoUserChecks opts) $ do |
379 | 6ec7a50e | Iustin Pop | runtimeEnts <- getEnts |
380 | 88a10df5 | Iustin Pop | ents <- exitIfBad "Can't find required user/groups" runtimeEnts |
381 | 88a10df5 | Iustin Pop | verifyDaemonUser daemon ents |
382 | 6ec7a50e | Iustin Pop | |
383 | b714ff89 | Iustin Pop | syslog <- case optSyslogUsage opts of |
384 | 88a10df5 | Iustin Pop | Nothing -> exitIfBad "Invalid cluster syslog setting" $ |
385 | b714ff89 | Iustin Pop | syslogUsageFromRaw C.syslogUsage |
386 | b714ff89 | Iustin Pop | Just v -> return v |
387 | 2ac2e420 | Iustin Pop | |
388 | 29a30533 | Iustin Pop | log_file <- daemonLogFile daemon |
389 | 2ac2e420 | Iustin Pop | -- run the check function and optionally exit if it returns an exit code |
390 | 2ac2e420 | Iustin Pop | check_result <- check_fn opts |
391 | 2ac2e420 | Iustin Pop | check_result' <- case check_result of |
392 | 2ac2e420 | Iustin Pop | Left code -> exitWith code |
393 | 2ac2e420 | Iustin Pop | Right v -> return v |
394 | 2ac2e420 | Iustin Pop | |
395 | 0c28bee1 | Iustin Pop | let processFn = if optDaemonize opts |
396 | 29a30533 | Iustin Pop | then daemonize log_file |
397 | b9097468 | Iustin Pop | else \action -> action Nothing |
398 | 2ac2e420 | Iustin Pop | processFn $ innerMain daemon opts syslog check_result' prep_fn exec_fn |
399 | 6ec7a50e | Iustin Pop | |
400 | b9097468 | Iustin Pop | -- | Full prepare function. |
401 | b9097468 | Iustin Pop | -- |
402 | b9097468 | Iustin Pop | -- This is executed after daemonization, and sets up both the log |
403 | b9097468 | Iustin Pop | -- files (a generic functionality) and the custom prepare function of |
404 | b9097468 | Iustin Pop | -- the daemon. |
405 | b9097468 | Iustin Pop | fullPrep :: GanetiDaemon -- ^ The daemon we're running |
406 | b9097468 | Iustin Pop | -> DaemonOptions -- ^ The options structure, filled from the cmdline |
407 | b9097468 | Iustin Pop | -> SyslogUsage -- ^ Syslog mode |
408 | b9097468 | Iustin Pop | -> a -- ^ Check results |
409 | b9097468 | Iustin Pop | -> PrepFn a b -- ^ Prepare function |
410 | b9097468 | Iustin Pop | -> IO b |
411 | b9097468 | Iustin Pop | fullPrep daemon opts syslog check_result prep_fn = do |
412 | 29a30533 | Iustin Pop | logfile <- if optDaemonize opts |
413 | 29a30533 | Iustin Pop | then return Nothing |
414 | 29a30533 | Iustin Pop | else liftM Just $ daemonLogFile daemon |
415 | 29a30533 | Iustin Pop | pidfile <- daemonPidFile daemon |
416 | 29a30533 | Iustin Pop | let dname = daemonName daemon |
417 | 48483a2e | Iustin Pop | setupLogging logfile dname (optDebug opts) True False syslog |
418 | e14b84e9 | Iustin Pop | _ <- describeError "writing PID file; already locked?" |
419 | e14b84e9 | Iustin Pop | Nothing (Just pidfile) $ writePidFile pidfile |
420 | 48483a2e | Iustin Pop | logNotice $ dname ++ " daemon startup" |
421 | b9097468 | Iustin Pop | prep_fn opts check_result |
422 | b9097468 | Iustin Pop | |
423 | 6ec7a50e | Iustin Pop | -- | Inner daemon function. |
424 | 6ec7a50e | Iustin Pop | -- |
425 | 6ec7a50e | Iustin Pop | -- This is executed after daemonization. |
426 | 2ac2e420 | Iustin Pop | innerMain :: GanetiDaemon -- ^ The daemon we're running |
427 | 2ac2e420 | Iustin Pop | -> DaemonOptions -- ^ The options structure, filled from the cmdline |
428 | 2ac2e420 | Iustin Pop | -> SyslogUsage -- ^ Syslog mode |
429 | 2ac2e420 | Iustin Pop | -> a -- ^ Check results |
430 | 2ac2e420 | Iustin Pop | -> PrepFn a b -- ^ Prepare function |
431 | 2ac2e420 | Iustin Pop | -> MainFn a b -- ^ Execution function |
432 | b9097468 | Iustin Pop | -> Maybe Fd -- ^ Error reporting function |
433 | 2ac2e420 | Iustin Pop | -> IO () |
434 | b9097468 | Iustin Pop | innerMain daemon opts syslog check_result prep_fn exec_fn fd = do |
435 | b9097468 | Iustin Pop | prep_result <- fullPrep daemon opts syslog check_result prep_fn |
436 | 1a865afe | Iustin Pop | `Control.Exception.catch` handlePrepErr True fd |
437 | b9097468 | Iustin Pop | -- no error reported, we should now close the fd |
438 | b9097468 | Iustin Pop | maybeCloseFd fd |
439 | 2ac2e420 | Iustin Pop | exec_fn opts check_result prep_result |
440 | b9097468 | Iustin Pop | |
441 | b9097468 | Iustin Pop | -- | Daemon prepare error handling function. |
442 | 1a865afe | Iustin Pop | handlePrepErr :: Bool -> Maybe Fd -> IOError -> IO a |
443 | 1a865afe | Iustin Pop | handlePrepErr logging_setup fd err = do |
444 | b9097468 | Iustin Pop | let msg = show err |
445 | b9097468 | Iustin Pop | case fd of |
446 | b9097468 | Iustin Pop | -- explicitly writing to the fd directly, since when forking it's |
447 | b9097468 | Iustin Pop | -- better (safer) than trying to convert this into a full handle |
448 | b9097468 | Iustin Pop | Just fd' -> fdWrite fd' msg >> return () |
449 | b9097468 | Iustin Pop | Nothing -> hPutStrLn stderr (daemonStartupErr msg) |
450 | 1a865afe | Iustin Pop | when logging_setup $ logError msg |
451 | b9097468 | Iustin Pop | exitWith $ ExitFailure 1 |
452 | b9097468 | Iustin Pop | |
453 | b9097468 | Iustin Pop | -- | Close a file descriptor. |
454 | b9097468 | Iustin Pop | maybeCloseFd :: Maybe Fd -> IO () |
455 | b9097468 | Iustin Pop | maybeCloseFd Nothing = return () |
456 | b9097468 | Iustin Pop | maybeCloseFd (Just fd) = closeFd fd |