root / src / Ganeti / Monitoring / Server.hs @ 006d6bc9
History | View | Annotate | Download (6.1 kB)
1 |
{-# LANGUAGE OverloadedStrings #-} |
---|---|
2 |
|
3 |
{-| Implementation of the Ganeti confd server functionality. |
4 |
|
5 |
-} |
6 |
|
7 |
{- |
8 |
|
9 |
Copyright (C) 2013 Google Inc. |
10 |
|
11 |
This program is free software; you can redistribute it and/or modify |
12 |
it under the terms of the GNU General Public License as published by |
13 |
the Free Software Foundation; either version 2 of the License, or |
14 |
(at your option) any later version. |
15 |
|
16 |
This program is distributed in the hope that it will be useful, but |
17 |
WITHOUT ANY WARRANTY; without even the implied warranty of |
18 |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
19 |
General Public License for more details. |
20 |
|
21 |
You should have received a copy of the GNU General Public License |
22 |
along with this program; if not, write to the Free Software |
23 |
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
24 |
02110-1301, USA. |
25 |
|
26 |
-} |
27 |
|
28 |
module Ganeti.Monitoring.Server |
29 |
( main |
30 |
, checkMain |
31 |
, prepMain |
32 |
) where |
33 |
|
34 |
import Control.Applicative |
35 |
import Control.Monad |
36 |
import Control.Monad.IO.Class |
37 |
import Data.ByteString.Char8 hiding (map, filter, find) |
38 |
import Data.List |
39 |
import Snap.Core |
40 |
import Snap.Http.Server |
41 |
import qualified Text.JSON as J |
42 |
|
43 |
import qualified Ganeti.BasicTypes as BT |
44 |
import Ganeti.Daemon |
45 |
import qualified Ganeti.DataCollectors.Diskstats as Diskstats |
46 |
import qualified Ganeti.DataCollectors.Drbd as Drbd |
47 |
import qualified Ganeti.DataCollectors.InstStatus as InstStatus |
48 |
import qualified Ganeti.DataCollectors.Lv as Lv |
49 |
import Ganeti.DataCollectors.Types |
50 |
import qualified Ganeti.Constants as C |
51 |
|
52 |
-- * Types and constants definitions |
53 |
|
54 |
-- | Type alias for checkMain results. |
55 |
type CheckResult = () |
56 |
|
57 |
-- | Type alias for prepMain results. |
58 |
type PrepResult = Config Snap () |
59 |
|
60 |
-- | Version of the latest supported http API. |
61 |
latestAPIVersion :: Int |
62 |
latestAPIVersion = 1 |
63 |
|
64 |
-- | Type describing a data collector basic information |
65 |
data DataCollector = DataCollector |
66 |
{ dName :: String -- ^ Name of the data collector |
67 |
, dCategory :: Maybe DCCategory -- ^ Category (storage, instance, ecc) |
68 |
-- of the collector |
69 |
, dKind :: DCKind -- ^ Kind (performance or status reporting) of |
70 |
-- the data collector |
71 |
, dReport :: IO DCReport -- ^ Report produced by the collector |
72 |
} |
73 |
|
74 |
-- | The list of available builtin data collectors. |
75 |
collectors :: [DataCollector] |
76 |
collectors = |
77 |
[ DataCollector Diskstats.dcName Diskstats.dcCategory Diskstats.dcKind |
78 |
Diskstats.dcReport |
79 |
, DataCollector Drbd.dcName Drbd.dcCategory Drbd.dcKind Drbd.dcReport |
80 |
, DataCollector InstStatus.dcName InstStatus.dcCategory InstStatus.dcKind |
81 |
InstStatus.dcReport |
82 |
, DataCollector Lv.dcName Lv.dcCategory Lv.dcKind Lv.dcReport |
83 |
] |
84 |
|
85 |
-- * Configuration handling |
86 |
|
87 |
-- | The default configuration for the HTTP server. |
88 |
defaultHttpConf :: Config Snap () |
89 |
defaultHttpConf = |
90 |
setAccessLog (ConfigFileLog C.daemonsExtraLogfilesGanetiMondAccess) . |
91 |
setCompression False . |
92 |
setErrorLog (ConfigFileLog C.daemonsExtraLogfilesGanetiMondError) $ |
93 |
setVerbose False |
94 |
emptyConfig |
95 |
|
96 |
-- * Helper functions |
97 |
|
98 |
-- | Check function for the monitoring agent. |
99 |
checkMain :: CheckFn CheckResult |
100 |
checkMain _ = return $ Right () |
101 |
|
102 |
-- | Prepare function for monitoring agent. |
103 |
prepMain :: PrepFn CheckResult PrepResult |
104 |
prepMain opts _ = |
105 |
return $ |
106 |
setPort (maybe C.defaultMondPort fromIntegral (optPort opts)) |
107 |
defaultHttpConf |
108 |
|
109 |
-- * Query answers |
110 |
|
111 |
-- | Reply to the supported API version numbers query. |
112 |
versionQ :: Snap () |
113 |
versionQ = writeBS . pack $ J.encode [latestAPIVersion] |
114 |
|
115 |
-- | Version 1 of the monitoring HTTP API. |
116 |
version1Api :: Snap () |
117 |
version1Api = |
118 |
let returnNull = writeBS . pack $ J.encode J.JSNull :: Snap () |
119 |
in ifTop returnNull <|> |
120 |
route |
121 |
[ ("list", listHandler) |
122 |
, ("report", reportHandler) |
123 |
] |
124 |
|
125 |
-- | Get the JSON representation of a data collector to be used in the collector |
126 |
-- list. |
127 |
dcListItem :: DataCollector -> J.JSValue |
128 |
dcListItem dc = |
129 |
J.JSArray |
130 |
[ J.showJSON $ dName dc |
131 |
, maybe J.JSNull J.showJSON $ dCategory dc |
132 |
, J.showJSON $ dKind dc |
133 |
] |
134 |
|
135 |
-- | Handler for returning lists. |
136 |
listHandler :: Snap () |
137 |
listHandler = |
138 |
dir "collectors" . writeBS . pack . J.encode $ map dcListItem collectors |
139 |
|
140 |
-- | Handler for returning data collector reports. |
141 |
reportHandler :: Snap () |
142 |
reportHandler = |
143 |
route |
144 |
[ ("all", allReports) |
145 |
, (":category/:collector", oneReport) |
146 |
] <|> |
147 |
errorReport |
148 |
|
149 |
-- | Return the report of all the available collectors. |
150 |
allReports :: Snap () |
151 |
allReports = do |
152 |
reports <- mapM (liftIO . dReport) collectors |
153 |
writeBS . pack . J.encode $ reports |
154 |
|
155 |
-- | Returns a category given its name. |
156 |
-- If "collector" is given as the name, the collector has no category, and |
157 |
-- Nothing will be returned. |
158 |
catFromName :: String -> BT.Result (Maybe DCCategory) |
159 |
catFromName "instance" = BT.Ok $ Just DCInstance |
160 |
catFromName "storage" = BT.Ok $ Just DCStorage |
161 |
catFromName "daemon" = BT.Ok $ Just DCDaemon |
162 |
catFromName "hypervisor" = BT.Ok $ Just DCHypervisor |
163 |
catFromName "default" = BT.Ok Nothing |
164 |
catFromName _ = BT.Bad "No such category" |
165 |
|
166 |
errorReport :: Snap () |
167 |
errorReport = do |
168 |
modifyResponse $ setResponseStatus 404 "Not found" |
169 |
writeBS "Unable to produce a report for the requested resource" |
170 |
|
171 |
error404 :: Snap () |
172 |
error404 = do |
173 |
modifyResponse $ setResponseStatus 404 "Not found" |
174 |
writeBS "Resource not found" |
175 |
|
176 |
-- | Return the report of one collector |
177 |
oneReport :: Snap () |
178 |
oneReport = do |
179 |
categoryName <- fmap (maybe mzero unpack) $ getParam "category" |
180 |
collectorName <- fmap (maybe mzero unpack) $ getParam "collector" |
181 |
category <- |
182 |
case catFromName categoryName of |
183 |
BT.Ok cat -> return cat |
184 |
BT.Bad msg -> fail msg |
185 |
collector <- |
186 |
case |
187 |
find (\col -> collectorName == dName col) $ |
188 |
filter (\c -> category == dCategory c) collectors of |
189 |
Just col -> return col |
190 |
Nothing -> fail "Unable to find the requested collector" |
191 |
report <- liftIO $ dReport collector |
192 |
writeBS . pack . J.encode $ report |
193 |
|
194 |
-- | The function implementing the HTTP API of the monitoring agent. |
195 |
monitoringApi :: Snap () |
196 |
monitoringApi = |
197 |
ifTop versionQ <|> |
198 |
dir "1" version1Api <|> |
199 |
error404 |
200 |
|
201 |
-- | Main function. |
202 |
main :: MainFn CheckResult PrepResult |
203 |
main _ _ httpConf = |
204 |
httpServe httpConf $ method GET monitoringApi |