Files
postgrest/src/PostgREST/Admin.hs
T

81 lines
3.0 KiB
Haskell

{-# LANGUAGE NamedFieldPuns #-}
module PostgREST.Admin
( runAdmin
) where
import qualified Data.Aeson as JSON
import qualified Hasql.Session as SQL
import qualified Network.HTTP.Types.Status as HTTP
import qualified Network.Wai as Wai
import qualified Network.Wai.Handler.Warp as Warp
import Control.Monad.Extra (whenJust)
import qualified Data.ByteString.Lazy as LBS
import Network.Socket
import Network.Socket.ByteString
import PostgREST.AppState (AppState)
import PostgREST.Config (AppConfig (..))
import PostgREST.Metrics (metricsToText)
import PostgREST.Observation (Observation (..))
import qualified PostgREST.AppState as AppState
import qualified PostgREST.Config as Config
import Protolude
runAdmin :: AppConfig -> AppState -> Warp.Settings -> IO ()
runAdmin conf@AppConfig{configAdminServerPort} appState settings =
whenJust (AppState.getSocketAdmin appState) $ \adminSocket -> do
observer $ AdminStartObs configAdminServerPort
void . forkIO $ Warp.runSettingsSocket settings adminSocket adminApp
where
adminApp = admin appState conf
observer = AppState.getObserver appState
-- | PostgREST admin application
admin :: AppState.AppState -> AppConfig -> Wai.Application
admin appState appConfig req respond = do
isMainAppReachable <- isRight <$> reachMainApp (AppState.getSocketREST appState)
isSchemaCacheLoaded <- AppState.getSchemaCacheLoaded appState
isConnectionUp <-
if configDbChannelEnabled appConfig
then AppState.getIsListenerOn appState
else isRight <$> AppState.usePool appState (SQL.sql "SELECT 1")
case Wai.pathInfo req of
["ready"] ->
respond $ Wai.responseLBS (if isMainAppReachable && isConnectionUp && isSchemaCacheLoaded then HTTP.status200 else HTTP.status503) [] mempty
["live"] ->
respond $ Wai.responseLBS (if isMainAppReachable then HTTP.status200 else HTTP.status503) [] mempty
["config"] -> do
config <- AppState.getConfig appState
respond $ Wai.responseLBS HTTP.status200 [] (LBS.fromStrict $ encodeUtf8 $ Config.toText config)
["schema_cache"] -> do
sCache <- AppState.getSchemaCache appState
respond $ Wai.responseLBS HTTP.status200 [] (maybe mempty JSON.encode sCache)
["metrics"] -> do
mets <- metricsToText
respond $ Wai.responseLBS HTTP.status200 [] mets
_ ->
respond $ Wai.responseLBS HTTP.status404 [] mempty
-- Try to connect to the main app socket
-- Note that it doesn't even send a valid HTTP request, we just want to check that the main app is accepting connections
reachMainApp :: Socket -> IO (Either IOException ())
reachMainApp appSock = do
sockAddr <- getSocketName appSock
sock <- socket (addrFamily sockAddr) Stream defaultProtocol
try $ do
connect sock sockAddr
withSocketsDo $ bracket (pure sock) close sendEmpty
where
sendEmpty sock = void $ send sock mempty
addrFamily (SockAddrInet _ _) = AF_INET
addrFamily (SockAddrInet6 {}) = AF_INET6
addrFamily (SockAddrUnix _) = AF_UNIX