module OptionalConfiguration (
OptionalConfiguration(..),
- from_rc )
+ from_rc,
+ merge_maybes )
where
import qualified Data.Configurator as DC (
import Data.Maybe ( fromMaybe )
import Data.Monoid ( Monoid(..) )
import Data.Typeable ( Typeable )
+import Paths_htsn ( getSysconfDir )
import System.Directory ( getHomeDirectory )
import System.FilePath ( (</>) )
import System.IO.Error ( catchIOError )
import System.Log ( Priority(..) )
-import Logging ( log_error )
-import TSN.FeedHosts ( FeedHosts(..) )
+
+import FeedHosts ( FeedHosts(..) )
+import Network.Services.TSN.Report ( report_error )
-- Derive standalone instances of Data and Typeable for Priority. This
--
data OptionalConfiguration =
OptionalConfiguration {
+ daemonize :: Maybe Bool,
feed_hosts :: FeedHosts,
log_file :: Maybe FilePath,
log_level :: Maybe Priority,
- password :: Maybe String,
output_directory :: Maybe FilePath,
+ password :: Maybe String,
+ pidfile :: Maybe FilePath,
+ run_as_group :: Maybe String,
+ run_as_user :: Maybe String,
syslog :: Maybe Bool,
username :: Maybe String }
deriving (Show, Data, Typeable)
+-- | Combine two Maybes into one, essentially mashing them
+-- together. We give precedence to the second argument when both are
+-- Justs.
+merge_maybes :: (Maybe a) -> (Maybe a) -> (Maybe a)
+merge_maybes Nothing Nothing = Nothing
+merge_maybes (Just x) Nothing = Just x
+merge_maybes Nothing (Just x) = Just x
+merge_maybes (Just _) (Just y) = Just y
+
+
-- | The Monoid instance for these lets us "combine" two
-- OptionalConfigurations. The "combine" operation that we'd like to
-- perform is, essentially, to mash them together. So if we have two
-- OptionalConfigurations, each half full, we could combine them
-- into one big one.
--
--- One of the two must take precedence during this mashing, and we
--- choose the second one for no reason.
---
-- This is used to merge command-line and config-file settings.
--
instance Monoid OptionalConfiguration where
-- | An empty OptionalConfiguration.
mempty = OptionalConfiguration
+ Nothing
(FeedHosts [])
Nothing
Nothing
Nothing
Nothing
Nothing
+ Nothing
+ Nothing
+ Nothing
-- | Combine @cfg1@ and @cfg2@, giving precedence to @cfg2@.
cfg1 `mappend` cfg2 =
OptionalConfiguration
+ (merge_maybes (daemonize cfg1) (daemonize cfg2))
all_feed_hosts
- (merge (log_file cfg1) (log_file cfg2))
- (merge (log_level cfg1) (log_level cfg2))
- (merge (password cfg1) (password cfg2))
- (merge (output_directory cfg1) (output_directory cfg2))
- (merge (syslog cfg1) (syslog cfg2))
- (merge (username cfg1) (username cfg2))
+ (merge_maybes (log_file cfg1) (log_file cfg2))
+ (merge_maybes (log_level cfg1) (log_level cfg2))
+ (merge_maybes (output_directory cfg1) (output_directory cfg2))
+ (merge_maybes (password cfg1) (password cfg2))
+ (merge_maybes (pidfile cfg1) (pidfile cfg2))
+ (merge_maybes (run_as_group cfg1) (run_as_group cfg2))
+ (merge_maybes (run_as_user cfg1) (run_as_user cfg2))
+ (merge_maybes (syslog cfg1) (syslog cfg2))
+ (merge_maybes (username cfg1) (username cfg2))
where
- merge :: (Maybe a) -> (Maybe a) -> (Maybe a)
- merge Nothing Nothing = Nothing
- merge (Just x) Nothing = Just x
- merge Nothing (Just x) = Just x
- merge (Just _) (Just y) = Just y
-
-- Use only the latter feed_hosts if there are any.
all_feed_hosts =
feed_hosts $ if (null (get_feed_hosts (feed_hosts cfg2)))
convert _ = Nothing
--- | Obtain an OptionalConfiguration from the file ".htsnrc" in the
--- user's home directory.
+-- | Obtain an OptionalConfiguration from htsnrc in either the global
+-- configuration directory or the user's home directory. The one in
+-- $HOME is prefixed by a dot so that it is hidden.
--
-- We make an attempt at cross-platform compatibility; we will try
--- to find the correct directory even on Windows. But if the call
--- to getHomeDirectory fails for whatever reason, we fall back to
--- using the environment variable $HOME.
+-- to find the correct directory even on Windows. But if the calls
+-- to getHomeDirectory/getSysconfDir fail for whatever reason, we
+-- fall back to using the Unix-specific /etc and $HOME.
--
from_rc :: IO OptionalConfiguration
from_rc = do
- -- After some thought, the "global" /etc/htsnrc configuration file
- -- was left out. Since each config file needs a password, and this
- -- should be run by a dedicated user anyway, the global file does
- -- not serve much purpose. It could also be a security risk (visible
- -- password) if the admin screws up.
+ etc <- catchIOError getSysconfDir (\e -> do
+ report_error (show e)
+ return "/etc")
home <- catchIOError getHomeDirectory (\e -> do
- log_error (show e)
+ report_error (show e)
return "$(HOME)")
+ let global_config_path = etc </> "htsnrc"
let user_config_path = home </> ".htsnrc"
- cfg <- DC.load [ DC.Optional user_config_path ]
+ cfg <- DC.load [ DC.Optional global_config_path,
+ DC.Optional user_config_path ]
+ cfg_daemonize <- DC.lookup cfg "daemonize"
+ cfg_feed_hosts <- DC.lookup cfg "feed_hosts"
cfg_log_file <- DC.lookup cfg "log_file"
cfg_log_level <- DC.lookup cfg "log_level"
- cfg_password <- DC.lookup cfg "password"
cfg_output_directory <- DC.lookup cfg "output_directory"
+ cfg_password <- DC.lookup cfg "password"
+ cfg_pidfile <- DC.lookup cfg "pidfile"
+ cfg_run_as_group <- DC.lookup cfg "run_as_group"
+ cfg_run_as_user <- DC.lookup cfg "run_as_user"
cfg_syslog <- DC.lookup cfg "syslog"
cfg_username <- DC.lookup cfg "username"
- cfg_feed_hosts <- DC.lookup cfg "feed_hosts"
return $ OptionalConfiguration
+ cfg_daemonize
(fromMaybe (FeedHosts []) cfg_feed_hosts)
cfg_log_file
cfg_log_level
- cfg_password
cfg_output_directory
+ cfg_password
+ cfg_pidfile
+ cfg_run_as_group
+ cfg_run_as_user
cfg_syslog
cfg_username
-