prometheus-wai 0.0.0.0 → 0.0.0.1

raw patch · 3 files changed

+52/−16 lines, 3 filesPVP: minor bump suggested

API additions: PVP suggests at least a minor version bump

API changes (from Hackage documentation)

Files

• CHANGELOG.md +9/−0
• prometheus-wai.cabal +3/−1
• src/System/Metrics/Prometheus/Wai/Middleware.hs +40/−15

@@ -0,0 +1,9 @@+# Changelog++## [0.0.0.1] - 2025-07-14++### Added++- `--skip-passed`: Skip passing tests and rerun once the entire suite is+  skipped.+

@@ -5,7 +5,7 @@ -- see: https://github.com/sol/hpack  name:           prometheus-wai-version:        0.0.0.0+version:        0.0.0.1 description:    Prometheus metrics for WAI applications homepage:       https://github.com/NorfairKing/prometheus-wai#readme bug-reports:    https://github.com/NorfairKing/prometheus-wai/issues@@ -14,6 +14,8 @@ copyright:      Copyright (c) 2025 Tom Sydney Kerckhove license:        MIT build-type:     Simple+extra-source-files:+    CHANGELOG.md  source-repository head   type: git

@@ -4,9 +4,11 @@  module System.Metrics.Prometheus.Wai.Middleware   ( registerWaiMetrics,+    WaiMetrics (..),     instrumentWaiMiddleware,     metricsEndpointMiddleware,     metricsEndpointAtMiddleware,+    metricsEndpointAtMiddlewareWithHook,   ) where @@ -31,8 +33,6 @@ import qualified System.Metrics.Prometheus.MetricId as Labels import qualified System.Metrics.Prometheus.MetricId as Prometheus (Labels (..)) --- TODO ignore websocket requests when gathering info- data WaiMetrics = WaiMetrics   { waiMetricsStatusCode :: !(Map Int Prometheus.Counter),     waiMetricsDuration :: !Prometheus.Histogram@@ -74,29 +74,54 @@  -- | Record the given Wai metrics in a middleware. instrumentWaiMiddleware :: WaiMetrics -> Wai.Middleware-instrumentWaiMiddleware WaiMetrics {..} application request sendResponse = do-  begin <- getMonotonicTimeNSec-  application request $ \response -> do-    end <- getMonotonicTimeNSec+instrumentWaiMiddleware WaiMetrics {..} application request sendResponse =+  let isWebSocketsReq =+        lookup "upgrade" (Wai.requestHeaders request) == Just "websocket"+      shouldInstrument =+        -- Don't instrument WebSocket requests because they don't have a+        -- response but some libraries still pretend that it does and will+        -- give it a 500 status code.+        -- Moreover, the 'latency' will be 'how long the connection was open'+        -- which is also useless.+        not isWebSocketsReq+   in if shouldInstrument+        then do+          begin <- getMonotonicTimeNSec+          application request $ \response -> do+            end <- getMonotonicTimeNSec -    -- Count the status code-    mapM_ Counter.inc (M.lookup (HTTP.statusCode (Wai.responseStatus response)) waiMetricsStatusCode)+            -- Count the status code+            mapM_ Counter.inc (M.lookup (HTTP.statusCode (Wai.responseStatus response)) waiMetricsStatusCode) -    -- Count the application response duration-    let nanos = end - begin-        millis = fromIntegral nanos / 1_000_000-    Histogram.observe millis waiMetricsDuration+            -- Count the application response duration+            let nanos = end - begin+                millis = fromIntegral nanos / 1_000_000+            Histogram.observe millis waiMetricsDuration -    sendResponse response+            sendResponse response+        else application request sendResponse --- | Add a metrics endpoint using the given industry.+-- | Add a metrics endpoint using the given registry. metricsEndpointMiddleware :: Registry -> Wai.Middleware metricsEndpointMiddleware = metricsEndpointAtMiddleware "/metrics" +-- | Add a metrics endpoint at a given path using the given registry. metricsEndpointAtMiddleware :: ByteString -> Registry -> Wai.Middleware-metricsEndpointAtMiddleware path registry application request sendResponse =+metricsEndpointAtMiddleware =+  metricsEndpointAtMiddlewareWithHook (pure ())++-- | Add a metrics endpoint at a given path and last-minute hook using the given registry.+--+-- This lets you set metrics that are evaluated when the /metrics endpoint is hit.+metricsEndpointAtMiddlewareWithHook ::+  IO () ->+  ByteString ->+  Registry ->+  Wai.Middleware+metricsEndpointAtMiddlewareWithHook lastMinuteHook path registry application request sendResponse =   if Request.rawPathInfo request == path     then do+      lastMinuteHook       s <- Registry.sample registry       sendResponse         $ Wai.responseBuilder