Add prometheus middleware to proxy

services/proxy/package.yaml

@@ -20,6 +20,7 @@ library:
   - Proxy.Env
   - Proxy.Options
   - Proxy.Proxy
+  - Proxy.Run
   dependencies:
   - base >=4.6 && <5
   - aeson >=1.0

services/proxy/src/Main.hs

@@ -1,7 +1,7 @@
 module Main (main) where
 
 import Imports
-import Proxy.API
+import Proxy.Run (run)
 import Proxy.Options
 import Util.Options
 

services/proxy/src/Proxy/API.hs

@@ -1,4 +1,4 @@
-module Proxy.API (Proxy.API.run) where
+module Proxy.API (sitemap) where
 
 import Imports hiding (head)
 import Control.Monad.Catch
@@ -7,19 +7,15 @@ import Control.Retry
 import Data.ByteString (breakSubstring)
 import Data.CaseInsensitive (CI)
 import Data.Metrics.Middleware hiding (path)
-import Data.Metrics.WaiRoute (treeToPaths)
 import Network.HTTP.ReverseProxy
 import Network.HTTP.Types
 import Network.Wai
-import Network.Wai.Handler.Warp
 import Network.Wai.Predicate hiding (err, Error, setStatus)
 import Network.Wai.Predicate.Request (getRequest)
 import Network.Wai.Routing hiding (path, route)
 import Network.Wai.Utilities
-import Network.Wai.Utilities.Server hiding (serverPort)
 import Proxy.Env
 import Proxy.Proxy
-import Proxy.Options
 import System.Logger.Class hiding (Error, info, render)
 
 import qualified Bilge.Request as Req
@@ -33,17 +29,6 @@ import qualified Network.HTTP.Client as Client
 import qualified Network.Wai.Internal as I
 import qualified System.Logger as Logger
 
-run :: Opts -> IO ()
-run o = do
-    m <- metrics
-    e <- createEnv m o
-    s <- newSettings $ defaultServer (o^.host) (o^.port) (e^.applog) m
-    let rtree    = compile (sitemap e)
-    let measured = measureRequests m (treeToPaths rtree)
-    let app r k  = runProxy e r (route rtree r k)
-    let start    = measured . catchErrors (e^.applog) m $ app
-    runSettings s start `finally` destroyEnv e
-
 sitemap :: Env -> Routes a Proxy ()
 sitemap e = do
 

services/proxy/src/Proxy/Run.hs

@@ -0,0 +1,27 @@
+module Proxy.Run (run) where
+
+import Imports hiding (head)
+import Control.Monad.Catch
+import Control.Lens hiding ((.=))
+import Data.Metrics.Middleware hiding (path)
+import Data.Metrics.Middleware.Prometheus (waiPrometheusMiddleware)
+import Data.Metrics.WaiRoute (treeToPaths)
+import Network.Wai.Utilities.Server hiding (serverPort)
+import Network.Wai.Handler.Warp (runSettings)
+import Proxy.Env
+import Proxy.Proxy
+import Proxy.Options
+import Proxy.API (sitemap)
+
+run :: Opts -> IO ()
+run o = do
+    m <- metrics
+    e <- createEnv m o
+    s <- newSettings $ defaultServer (o^.host) (o^.port) (e^.applog) m
+    let rtree    = compile (sitemap e)
+    let measured = measureRequests m (treeToPaths rtree)
+    let app r k  = runProxy e r (route rtree r k)
+    let middleware = waiPrometheusMiddleware (sitemap e)
+                   . measured
+                   . catchErrors (e^.applog) m
+    runSettings s (middleware app) `finally` destroyEnv e