Files
postgrest/src/PostgREST/Admin.hs
T
Taimoor ZaeemandSteve Chavez 41b6ebea58 refactor: deduplicate host resolution logic and observations
Replaces the "API server listening on unix socket" with simpler
"API server listening on " observation. This allows refactoring
redundant code.

Signed-off-by: Taimoor Zaeem <taimoorzaeem@gmail.com>
2025-09-01 15:00:20 -05:00

75 lines
2.8 KiB
Haskell

module PostgREST.Admin
( runAdmin
) where
import qualified Data.Aeson as JSON
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 Network.Socket hiding (addrFamily)
import Network.Socket.ByteString
import PostgREST.AppState (AppState)
import PostgREST.MediaType (MediaType (..), toContentType)
import PostgREST.Metrics (metricsToText)
import PostgREST.Network (resolveSocketToAddress)
import PostgREST.Observation (Observation (..))
import qualified PostgREST.AppState as AppState
import Protolude
runAdmin :: AppState -> Warp.Settings -> IO ()
runAdmin appState settings = do
whenJust (AppState.getSocketAdmin appState) $ \adminSocket -> do
address <- resolveSocketToAddress adminSocket
observer $ AdminStartObs address
void . forkIO $ Warp.runSettingsSocket settings adminSocket adminApp
where
adminApp = admin appState
observer = AppState.getObserver appState
-- | PostgREST admin application
admin :: AppState.AppState -> Wai.Application
admin appState req respond = do
isMainAppReachable <- isRight <$> reachMainApp (AppState.getSocketREST appState)
isLoaded <- AppState.isLoaded appState
isPending <- AppState.isPending appState
case Wai.pathInfo req of
["live"] ->
respond $ Wai.responseLBS (if isMainAppReachable then HTTP.status200 else HTTP.status500) [] mempty
["ready"] ->
let
status | not isMainAppReachable = HTTP.status500
| isPending = HTTP.status503
| isLoaded = HTTP.status200
| otherwise = HTTP.status500
in
respond $ Wai.responseLBS status [] mempty
["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 [toContentType MTTextPlain] mets -- Content-Type is required for prometheus compliance
_ ->
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