Define metrics using Prometheus.unsafeRegister instead of having th…

…e metrics-core wrapper (#4085)

* catchErrors middleware: Always record metrics

Instead of relying on `Metrics`, use top-level metric registered using
`unsafeRegister`.

* Use `unsafeRegister` for metrics instead of bunch of IORef HashMaps

* federator: Enable GC metrics

changelog.d/5-internal/federator-metrics

@@ -0,0 +1 @@
+federator: Add metrics for garbage collections and unexpected errors that were caught

changelog.d/5-internal/metrics-core

@@ -0,0 +1 @@
+metrics-core: Delete `Data.Metrics` in favour of defining metrics closer to where they are being emitted

libs/metrics-core/default.nix

@@ -4,31 +4,23 @@
 # dependencies are added or removed.
 { mkDerivation
 , base
-, containers
 , gitignoreSource
-, hashable
 , immortal
 , imports
 , lib
 , prometheus-client
-, text
 , time
-, unordered-containers
 }:
 mkDerivation {
   pname = "metrics-core";
   version = "0.3.2";
   src = gitignoreSource ./.;
   libraryHaskellDepends = [
     base
-    containers
-    hashable
     immortal
     imports
     prometheus-client
-    text
     time
-    unordered-containers
   ];
   description = "Metrics core";
   license = lib.licenses.agpl3Only;

libs/metrics-core/metrics-core.cabal

@@ -12,7 +12,6 @@ build-type:    Simple
 
 library
   exposed-modules:
-    Data.Metrics
     Data.Metrics.AWS
     Data.Metrics.GC
 
@@ -66,14 +65,10 @@ library
     -Wredundant-constraints -Wunused-packages
 
   build-depends:
-      base                  >=4.9
-    , containers
-    , hashable              >=1.2
+      base               >=4.9
     , immortal
     , imports
     , prometheus-client
-    , text                  >=0.11
     , time
-    , unordered-containers  >=0.2
 
   default-language:   GHC2021

libs/metrics-core/src/Data/Metrics/AWS.hs

@@ -16,14 +16,24 @@
 
 module Data.Metrics.AWS (gaugeTokenRemaing) where
 
-import Data.Metrics (Metrics, gaugeSet, path)
 import Data.Time
 import Imports
+import Prometheus qualified as Prom
 
-gaugeTokenRemaing :: Metrics -> Maybe NominalDiffTime -> IO ()
-gaugeTokenRemaing m mbRemaining = do
+gaugeTokenRemaing :: Maybe NominalDiffTime -> IO ()
+gaugeTokenRemaing mbRemaining = do
   let t = toSeconds (fromMaybe 0 mbRemaining)
-  gaugeSet t (path "aws_auth.token_secs_remaining") m
+  Prom.setGauge awsAuthTokenSecsRemaining t
   where
     toSeconds :: NominalDiffTime -> Double
     toSeconds = fromRational . toRational
+
+{-# NOINLINE awsAuthTokenSecsRemaining #-}
+awsAuthTokenSecsRemaining :: Prom.Gauge
+awsAuthTokenSecsRemaining =
+  Prom.unsafeRegister $
+    Prom.gauge
+      Prom.Info
+        { Prom.metricName = "aws_auth.token_secs_remaining",
+          Prom.metricHelp = "Number of seconds left before AWS Auth expires"
+        }