root / src / Ganeti / Logging.hs @ b9202225
History | View | Annotate | Download (4.9 kB)
1 |
{-# LANGUAGE TemplateHaskell #-} |
---|---|
2 |
|
3 |
{-| Implementation of the Ganeti logging functionality. |
4 |
|
5 |
This currently lacks the following (FIXME): |
6 |
|
7 |
- log file reopening |
8 |
|
9 |
Note that this requires the hslogger library version 1.1 and above. |
10 |
|
11 |
-} |
12 |
|
13 |
{- |
14 |
|
15 |
Copyright (C) 2011, 2012, 2013 Google Inc. |
16 |
|
17 |
This program is free software; you can redistribute it and/or modify |
18 |
it under the terms of the GNU General Public License as published by |
19 |
the Free Software Foundation; either version 2 of the License, or |
20 |
(at your option) any later version. |
21 |
|
22 |
This program is distributed in the hope that it will be useful, but |
23 |
WITHOUT ANY WARRANTY; without even the implied warranty of |
24 |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
25 |
General Public License for more details. |
26 |
|
27 |
You should have received a copy of the GNU General Public License |
28 |
along with this program; if not, write to the Free Software |
29 |
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
30 |
02110-1301, USA. |
31 |
|
32 |
-} |
33 |
|
34 |
module Ganeti.Logging |
35 |
( setupLogging |
36 |
, MonadLog(..) |
37 |
, Priority(..) |
38 |
, logDebug |
39 |
, logInfo |
40 |
, logNotice |
41 |
, logWarning |
42 |
, logError |
43 |
, logCritical |
44 |
, logAlert |
45 |
, logEmergency |
46 |
, SyslogUsage(..) |
47 |
, syslogUsageToRaw |
48 |
, syslogUsageFromRaw |
49 |
) where |
50 |
|
51 |
import Control.Monad |
52 |
import Control.Monad.Reader |
53 |
import System.Log.Logger |
54 |
import System.Log.Handler.Simple |
55 |
import System.Log.Handler.Syslog |
56 |
import System.Log.Handler (setFormatter, LogHandler) |
57 |
import System.Log.Formatter |
58 |
import System.IO |
59 |
|
60 |
import Ganeti.THH |
61 |
import qualified Ganeti.ConstantUtils as ConstantUtils |
62 |
|
63 |
-- | Syslog usage type. |
64 |
$(declareLADT ''String "SyslogUsage" |
65 |
[ ("SyslogNo", "no") |
66 |
, ("SyslogYes", "yes") |
67 |
, ("SyslogOnly", "only") |
68 |
]) |
69 |
|
70 |
-- | Builds the log formatter. |
71 |
logFormatter :: String -- ^ Program |
72 |
-> Bool -- ^ Multithreaded |
73 |
-> Bool -- ^ Syslog |
74 |
-> LogFormatter a |
75 |
logFormatter prog mt syslog = |
76 |
let parts = [ if syslog |
77 |
then "[$pid]:" |
78 |
else "$time: " ++ prog ++ " pid=$pid" |
79 |
, if mt then if syslog then " ($tid)" else "/$tid" |
80 |
else "" |
81 |
, " $prio $msg" |
82 |
] |
83 |
in tfLogFormatter "%F %X,%q %Z" $ concat parts |
84 |
|
85 |
-- | Helper to open and set the formatter on a log if enabled by a |
86 |
-- given condition, otherwise returning an empty list. |
87 |
openFormattedHandler :: (LogHandler a) => Bool |
88 |
-> LogFormatter a -> IO a -> IO [a] |
89 |
openFormattedHandler False _ _ = return [] |
90 |
openFormattedHandler True fmt opener = do |
91 |
handler <- opener |
92 |
return [setFormatter handler fmt] |
93 |
|
94 |
-- | Sets up the logging configuration. |
95 |
setupLogging :: Maybe String -- ^ Log file |
96 |
-> String -- ^ Program name |
97 |
-> Bool -- ^ Debug level |
98 |
-> Bool -- ^ Log to stderr |
99 |
-> Bool -- ^ Log to console |
100 |
-> SyslogUsage -- ^ Syslog usage |
101 |
-> IO () |
102 |
setupLogging logf program debug stderr_logging console syslog = do |
103 |
let level = if debug then DEBUG else INFO |
104 |
destf = if console then Just ConstantUtils.devConsole else logf |
105 |
fmt = logFormatter program False False |
106 |
file_logging = syslog /= SyslogOnly |
107 |
|
108 |
updateGlobalLogger rootLoggerName (setLevel level) |
109 |
|
110 |
stderr_handlers <- openFormattedHandler stderr_logging fmt $ |
111 |
streamHandler stderr level |
112 |
|
113 |
file_handlers <- case destf of |
114 |
Nothing -> return [] |
115 |
Just path -> openFormattedHandler file_logging fmt $ |
116 |
fileHandler path level |
117 |
|
118 |
let handlers = file_handlers ++ stderr_handlers |
119 |
updateGlobalLogger rootLoggerName $ setHandlers handlers |
120 |
-- syslog handler is special (another type, still instance of the |
121 |
-- typeclass, and has a built-in formatter), so we can't pass it in |
122 |
-- the above list |
123 |
when (syslog /= SyslogNo) $ do |
124 |
syslog_handler <- openlog program [PID] DAEMON INFO |
125 |
updateGlobalLogger rootLoggerName $ addHandler syslog_handler |
126 |
|
127 |
-- * Logging function aliases |
128 |
|
129 |
-- | A monad that allows logging. |
130 |
class Monad m => MonadLog m where |
131 |
-- | Log at a given level. |
132 |
logAt :: Priority -> String -> m () |
133 |
|
134 |
instance MonadLog IO where |
135 |
logAt = logM rootLoggerName |
136 |
|
137 |
instance (MonadLog m) => MonadLog (ReaderT r m) where |
138 |
logAt p x = lift $ logAt p x |
139 |
|
140 |
-- | Log at debug level. |
141 |
logDebug :: (MonadLog m) => String -> m () |
142 |
logDebug = logAt DEBUG |
143 |
|
144 |
-- | Log at info level. |
145 |
logInfo :: (MonadLog m) => String -> m () |
146 |
logInfo = logAt INFO |
147 |
|
148 |
-- | Log at notice level. |
149 |
logNotice :: (MonadLog m) => String -> m () |
150 |
logNotice = logAt NOTICE |
151 |
|
152 |
-- | Log at warning level. |
153 |
logWarning :: (MonadLog m) => String -> m () |
154 |
logWarning = logAt WARNING |
155 |
|
156 |
-- | Log at error level. |
157 |
logError :: (MonadLog m) => String -> m () |
158 |
logError = logAt ERROR |
159 |
|
160 |
-- | Log at critical level. |
161 |
logCritical :: (MonadLog m) => String -> m () |
162 |
logCritical = logAt CRITICAL |
163 |
|
164 |
-- | Log at alert level. |
165 |
logAlert :: (MonadLog m) => String -> m () |
166 |
logAlert = logAt ALERT |
167 |
|
168 |
-- | Log at emergency level. |
169 |
logEmergency :: (MonadLog m) => String -> m () |
170 |
logEmergency = logAt EMERGENCY |