Work in progress

webapp/sources/rudder/rudder-core/src/main/scala/com/normation/rudder/services/healthcheck/HealthcheckService.scala

@@ -3,14 +3,20 @@ package com.normation.rudder.services.healthcheck
 import java.lang.Runtime.getRuntime
 
 import com.normation.errors.IOResult
+import com.normation.errors.Inconsistency
 import com.normation.rudder.domain.logger.{HealthcheckLoggerPure => logger}
+import com.normation.rudder.hooks.Cmd
+import com.normation.rudder.hooks.RunNuCommand
 import com.normation.rudder.services.healthcheck.HealthcheckResult.Critical
 import com.normation.rudder.services.healthcheck.HealthcheckResult.Warning
 import com.normation.rudder.services.healthcheck.HealthcheckResult.Ok
+import com.normation.rudder.services.nodes.NodeInfoService
 import zio.UIO
 import zio.ZIO
 import zio.syntax.ToZio
 
+import scala.util.Try
+
 final case class CheckName(value: String)
 
 trait Check {
@@ -62,7 +68,7 @@ class HealthcheckService(checks: List[Check]) {
   }
 }
 
-final object CheckCoreNumber extends Check {
+final class CheckCoreNumber extends Check {
   def name: CheckName = CheckName("CPU Cores available")
   def run: IOResult[HealthcheckResult] = for {
     availableCores <- IOResult.effect(getRuntime.availableProcessors)
@@ -73,4 +79,37 @@ final object CheckCoreNumber extends Check {
       case n => Ok(name, s"${n} cores available")
     }
   }
+}
+
+// How to get a service in this check, or find another way to get number of node
+// Should I transform this into a class ?
+final object CheckFileDescriptorLimit extends Check {
+  def name: CheckName = CheckName("File descriptor limit")
+  def run: IOResult[HealthcheckResult] = {
+    // Check the soft limit.
+    // That can be raise or lower by any user but cannot exceed the hard limit provided by parameter "-Hn"
+    // "-Sn" correspond to [S]oft and limit [n]umber of opened file descriptor
+    val cmd = Cmd("ulimit", "-Sn" :: Nil, Map.empty)
+
+    for {
+      fdLimitCmd <- RunNuCommand.run(cmd)
+      res       <- fdLimitCmd.await
+      _         <- ZIO.when(res.code != 0) {
+                     Inconsistency(
+                       s"An error occurred while getting file descriptor soft limit with command '${cmd.display}':\n code: ${res.code}\n stderr: ${res.stderr}\n stdout: ${res.stdout}"
+                     ).fail
+                   }
+      limit <- IOResult.effect(res.stdout.toInt) // not sure about to handle a toInt with a possible exception
+    } yield {
+      val numNode = 31 // NodeInfoService.getNumberOfManagedNodes or NodeInfoServiceCached.getNumberOfManagedNodes
+      limit match {
+        case limit if limit <= 10_000 =>
+          Critical(name, s"The limit of ${limit} opened file descriptor is not enough")
+        case limit if limit <= (100 * numNode) =>  // what if nb node < 100 ?
+          Warning(name, s"The limit of ${limit} opened file descriptor may cause trouble")
+        case _ =>
+          Ok(name, s"The limit of ${limit} is acceptable")
+      }
+    }
+  }
 }