Tracing doodles

lambda-natchez/src/main/scala/feral/lambda/natchez/Tags.scala

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.lambda.natchez
+
+import natchez.TraceValue
+
+object Tags {
+  private[this] val prefix = "aws"
+  def arn(s: String): (String, TraceValue) = s"$prefix.arn" -> s
+  def requestId(s: String): (String, TraceValue) = s"$prefix.requestId" -> s
+}

lambda-natchez/src/main/scala/feral/lambda/natchez/TracedLambda.scala

@@ -16,18 +16,26 @@
 
 package feral.lambda.natchez
 
+import cats.Monad
 import cats.effect.kernel.MonadCancelThrow
+import cats.syntax.all._
 import feral.lambda.Lambda
 import natchez.EntryPoint
 import natchez.Trace
 
 object TracedLambda {
-  def apply[F[_]: MonadCancelThrow, G[_], Event: HasKernel, Result](entryPoint: EntryPoint[F])(
-      lambda: Trace[G] => Lambda[G, Event, Result])(
-      implicit lift: LiftTrace[F, G]): Lambda[F, Event, Result] = { (event, context) =>
+  def apply[F[_]: MonadCancelThrow, G[_]: Monad, Event: HasKernel, Result](
+      entryPoint: EntryPoint[F])(
+      lambda: Trace[G] => Lambda[G, Event, Result]
+  )(implicit lift: LiftTrace[F, G]): Lambda[F, Event, Result] = { (event, context) =>
     val kernel = HasKernel[Event].extract(event)
     entryPoint.continueOrElseRoot(context.functionName, kernel).use { span =>
-      lift.run(span)(lambda(_)(event, context.mapK(lift.liftK)))
+      lift.run(span) { trace =>
+        trace.put(
+          Tags.arn(context.invokedFunctionArn),
+          Tags.requestId(context.awsRequestId)
+        ) >> lambda(trace)(event, context.mapK(lift.liftK))
+      }
     }
   }
 }