Use IO monad when starting servers

Change-Id: I3e97161535fc721dda6109c4cb5f23a1db0afde3
Signed-off-by: Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
Issue-ID: DCAEGEN2-601

1 files changed, 21 insertions, 13 deletions

diff --git a/hv-collector-dcae-app-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/dcaeapp/main.kt b/hv-collector-dcae-app-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/dcaeapp/main.kt
index f7d44ede..a8a4cf5a 100644
--- a/hv-collector-dcae-app-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/dcaeapp/main.kt
+++ b/hv-collector-dcae-app-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/dcaeapp/main.kt
@@ -19,30 +19,38 @@
  */
 package org.onap.dcae.collectors.veshv.simulators.dcaeapp
 
-import arrow.core.Failure
-import arrow.core.Success
 import org.onap.dcae.collectors.veshv.simulators.dcaeapp.config.ArgBasedDcaeAppSimConfiguration
 import org.onap.dcae.collectors.veshv.simulators.dcaeapp.config.DcaeAppSimConfiguration
 import org.onap.dcae.collectors.veshv.simulators.dcaeapp.kafka.KafkaSource
 import org.onap.dcae.collectors.veshv.simulators.dcaeapp.remote.ApiServer
-import org.onap.dcae.collectors.veshv.utils.commandline.handleErrorsInMain
+import org.onap.dcae.collectors.veshv.utils.arrow.ExitFailure
+import org.onap.dcae.collectors.veshv.utils.arrow.unsafeRunEitherSync
+import org.onap.dcae.collectors.veshv.utils.arrow.void
+import org.onap.dcae.collectors.veshv.utils.commandline.handleWrongArgumentErrorCurried
 import org.onap.dcae.collectors.veshv.utils.logging.Logger
 import org.slf4j.LoggerFactory
 
-private val logger = Logger(LoggerFactory.getLogger("DCAE simulator :: main"))
+private const val PACKAGE_NAME = "org.onap.dcae.collectors.veshv.simulators.dcaeapp"
+private val logger = Logger(PACKAGE_NAME)
+const val PROGRAM_NAME = "java $PACKAGE_NAME.MainKt"
 
-fun main(args: Array<String>) {
-    logger.info("Starting DCAE APP simulator")
+fun main(args: Array<String>) =
+        ArgBasedDcaeAppSimConfiguration().parse(args)
+                .mapLeft(handleWrongArgumentErrorCurried(PROGRAM_NAME))
+                .map(::startApp)
+                .unsafeRunEitherSync(
+                        { ex ->
+                            logger.error("Failed to start a server", ex)
+                            ExitFailure(1)
+                        },
+                        {
+                            logger.info("Started DCAE-APP Simulator API server")
+                        }
+                )
 
-    val config = ArgBasedDcaeAppSimConfiguration().parse(args)
-    when (config) {
-        is Success -> startApp(config.value).unsafeRunSync()
-        is Failure -> config.handleErrorsInMain("", logger)
-    }
-}
 
 private fun startApp(config: DcaeAppSimConfiguration) =
         KafkaSource.create(config.kafkaBootstrapServers, config.kafkaTopics)
                 .start()
                 .map(::ApiServer)
-                .flatMap { it.start(config.apiPort) }
+                .flatMap { it.start(config.apiPort).void() }