Blammo.Logging.LogSettings.Env

Produce a LogSettings by reading environment variables

• LOG_LEVEL: a known log level (case insensitive) and optional levels by source. See Logging.LogSettings.LogLevels.
• LOG_DESTINATION: the string stderr or stdout (case sensitive), or @{path} to log to the file at path. Unrecognized values will produce and error.
• LOG_FORMAT: the string tty or json. Unrecognized values will produce an error.
• LOG_COLOR: the string auto, always, or never. Other values may be recognized (e.g. yes or no) but should not be relied on. Unrecognized values will produce an error

This module is meant to be imported qualified.

import Blammo.Logging
import qualified Logging.LogSettings.Env as Env

main :: IO ()
main = do
  logger <- newLogger =<< Env.parse
  runLoggerLoggingT logger $ -- ...

Documentation

parse :: IO LogSettings

parser :: Parser Error LogSettings

Specifying defaults other than defaultLogSettings

For example, if you want logging to go to stderr by default, but still support LOG_DESTINATION,

settings <- Env.parseWith
  $ setLogSettingsDestination LogDestinationStderr defaultLogSettings

parseWith :: LogSettings -> IO LogSettings

parserWith :: LogSettings -> Parser Error LogSettings