Custom detekt rule for logger usage check

Check if logger invocations don't use unoptimal invocations, eg.
concatenation `debug("a=" + a)` instead of lambda use `debug {"a=" + a}`

Unfortunately to avoid defining dependencies in many places and having
circural dependencies it was necessarry to reorganize the maven module
structure. The goal was to have `sources` module with production code and
`build` module with build-time tooling (detekt rules among them).

Issue-ID: DCAEGEN2-1002
Change-Id: I36e677b98972aaae6905d722597cbce5e863d201
Signed-off-by: Piotr Jaszczyk <piotr.jaszczyk@nokia.com>

11 files changed, 820 insertions, 0 deletions

diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/arrow/core.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/arrow/core.kt
new file mode 100644
index 00000000..7381592d
--- /dev/null
+++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/arrow/core.kt
@@ -0,0 +1,47 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.utils.arrow
+
+import arrow.core.Either
+import arrow.core.Option
+import arrow.core.identity
+import arrow.syntax.collections.firstOption
+import java.util.concurrent.atomic.AtomicReference
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since July 2018
+ */
+
+fun <A> Either<A, A>.flatten() = fold(::identity, ::identity)
+
+fun <B> Either<Throwable, B>.rightOrThrow() = fold({ throw it }, ::identity)
+
+fun <A, B> Either<A, B>.rightOrThrow(mapper: (A) -> Throwable) = fold({ throw mapper(it) }, ::identity)
+
+fun <A> AtomicReference<A>.getOption() = Option.fromNullable(get())
+
+fun <A> Option.Companion.fromNullablesChain(firstValue: A?, vararg nextValues: () -> A?): Option<A> =
+        if (firstValue != null)
+            Option.just(firstValue)
+        else nextValues.asSequence()
+                .map { it() }
+                .filter { it != null }
+                .firstOption()
diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/arrow/effects.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/arrow/effects.kt
new file mode 100644
index 00000000..05d13094
--- /dev/null
+++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/arrow/effects.kt
@@ -0,0 +1,69 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.utils.arrow
+
+import arrow.core.Either
+import arrow.core.Left
+import arrow.core.Right
+import arrow.effects.IO
+import reactor.core.publisher.Flux
+import reactor.core.publisher.Mono
+import kotlin.system.exitProcess
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since June 2018
+ */
+
+sealed class ExitCode {
+    abstract val code: Int
+
+    fun io() = IO {
+        exitProcess(code)
+    }
+}
+
+object ExitSuccess : ExitCode() {
+    override val code = 0
+}
+
+data class ExitFailure(override val code: Int) : ExitCode()
+
+fun Either<IO<Unit>, IO<Unit>>.unsafeRunEitherSync(onError: (Throwable) -> ExitCode, onSuccess: () -> Unit) =
+        flatten().attempt().unsafeRunSync().fold({ onError(it).io().unsafeRunSync() }, { onSuccess() })
+
+
+fun IO<Any>.unit() = map { Unit }
+
+fun <T> Mono<T>.asIo() = IO.async<T> { callback ->
+    subscribe({
+        callback(Right(it))
+    }, {
+        callback(Left(it))
+    })
+}
+
+fun <T> Flux<IO<T>>.evaluateIo(): Flux<T> =
+        flatMap { io ->
+            io.attempt().unsafeRunSync().fold(
+                    { Flux.error<T>(it) },
+                    { Flux.just<T>(it) }
+            )
+        }
diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/ArgBasedConfiguration.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/ArgBasedConfiguration.kt
new file mode 100644
index 00000000..b14f1be5
--- /dev/null
+++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/ArgBasedConfiguration.kt
@@ -0,0 +1,57 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.utils.commandline
+
+import arrow.core.Either
+import arrow.core.Option
+import arrow.core.Try
+import arrow.core.flatMap
+import org.apache.commons.cli.CommandLine
+import org.apache.commons.cli.CommandLineParser
+import org.apache.commons.cli.Options
+import java.io.File
+import java.nio.file.Path
+import java.nio.file.Paths
+
+abstract class ArgBasedConfiguration<T>(private val parser: CommandLineParser) {
+    abstract val cmdLineOptionsList: List<CommandLineOption>
+
+    fun parse(args: Array<out String>): Either<WrongArgumentError, T> {
+        val parseResult = Try {
+            val commandLineOptions = cmdLineOptionsList.map { it.option }.fold(Options(), Options::addOption)
+            parser.parse(commandLineOptions, args)
+        }
+        return parseResult
+                .toEither()
+                .mapLeft { ex -> WrongArgumentError(ex, cmdLineOptionsList) }
+                .map(this::getConfiguration)
+                .flatMap {
+                    it.toEither {
+                        WrongArgumentError(
+                                message = "Unexpected error when parsing command line arguments",
+                                cmdLineOptionsList = cmdLineOptionsList)
+                    }
+                }
+    }
+
+    protected abstract fun getConfiguration(cmdLine: CommandLine): Option<T>
+
+    protected fun stringPathToPath(path: String): Path = Paths.get(File(path).toURI())
+}
diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/CommandLineOption.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/CommandLineOption.kt
new file mode 100644
index 00000000..9439bff5
--- /dev/null
+++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/CommandLineOption.kt
@@ -0,0 +1,142 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.utils.commandline
+
+import org.apache.commons.cli.Option
+
+
+enum class CommandLineOption(val option: Option, val required: Boolean = false) {
+    HEALTH_CHECK_API_PORT(Option.builder("H")
+            .longOpt("health-check-api-port")
+            .hasArg()
+            .desc("Health check rest api listen port")
+            .build()
+    ),
+    LISTEN_PORT(Option.builder("p")
+            .longOpt("listen-port")
+            .hasArg()
+            .desc("Listen port")
+            .build(),
+            required = true
+    ),
+    CONSUL_CONFIG_URL(Option.builder("c")
+            .longOpt("config-url")
+            .hasArg()
+            .desc("URL of ves configuration on consul")
+            .build(),
+            required = true
+    ),
+    CONSUL_FIRST_REQUEST_DELAY(Option.builder("d")
+            .longOpt("first-request-delay")
+            .hasArg()
+            .desc("Delay of first request to consul in seconds")
+            .build()
+    ),
+    CONSUL_REQUEST_INTERVAL(Option.builder("I")
+            .longOpt("request-interval")
+            .hasArg()
+            .desc("Interval of consul configuration requests in seconds")
+            .build()
+    ),
+    VES_HV_PORT(Option.builder("v")
+            .longOpt("ves-port")
+            .hasArg()
+            .desc("VesHvCollector port")
+            .build(),
+            required = true
+    ),
+    VES_HV_HOST(Option.builder("h")
+            .longOpt("ves-host")
+            .hasArg()
+            .desc("VesHvCollector host")
+            .build(),
+            required = true
+    ),
+    KAFKA_SERVERS(Option.builder("s")
+            .longOpt("kafka-bootstrap-servers")
+            .hasArg()
+            .desc("Comma-separated Kafka bootstrap servers in <host>:<port> format")
+            .build(),
+            required = true
+    ),
+    KAFKA_TOPICS(Option.builder("f")
+            .longOpt("kafka-topics")
+            .hasArg()
+            .desc("Comma-separated Kafka topics")
+            .build(),
+            required = true
+    ),
+    SSL_DISABLE(Option.builder("l")
+            .longOpt("ssl-disable")
+            .desc("Disable SSL encryption")
+            .build()
+    ),
+    KEY_STORE_FILE(Option.builder("k")
+            .longOpt("key-store")
+            .hasArg()
+            .desc("Key store in PKCS12 format")
+            .build()
+    ),
+    KEY_STORE_PASSWORD(Option.builder("kp")
+            .longOpt("key-store-password")
+            .hasArg()
+            .desc("Key store password")
+            .build()
+    ),
+    TRUST_STORE_FILE(Option.builder("t")
+            .longOpt("trust-store")
+            .hasArg()
+            .desc("File with trusted certificate bundle in PKCS12 format")
+            .build()
+    ),
+    TRUST_STORE_PASSWORD(Option.builder("tp")
+            .longOpt("trust-store-password")
+            .hasArg()
+            .desc("Trust store password")
+            .build()
+    ),
+    IDLE_TIMEOUT_SEC(Option.builder("i")
+            .longOpt("idle-timeout-sec")
+            .hasArg()
+            .desc("""Idle timeout for remote hosts. After given time without any data exchange the
+                |connection might be closed.""".trimMargin())
+            .build()
+    ),
+    MAXIMUM_PAYLOAD_SIZE_BYTES(Option.builder("m")
+            .longOpt("max-payload-size")
+            .hasArg()
+            .desc("Maximum supported payload size in bytes")
+            .build()
+    ),
+    DUMMY_MODE(Option.builder("u")
+            .longOpt("dummy")
+            .desc("If present will start in dummy mode (dummy external services)")
+            .build()
+    );
+
+    fun environmentVariableName(prefix: String = DEFAULT_ENV_PREFIX): String =
+            option.longOpt.toUpperCase().replace('-', '_').let { mainPart ->
+                "${prefix}_${mainPart}"
+            }
+
+    companion object {
+        private const val DEFAULT_ENV_PREFIX = "VESHV"
+    }
+}
diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/WrongArgumentError.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/WrongArgumentError.kt
new file mode 100644
index 00000000..9c2a20c1
--- /dev/null
+++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/WrongArgumentError.kt
@@ -0,0 +1,70 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.utils.commandline
+
+import arrow.core.Option
+import org.apache.commons.cli.HelpFormatter
+import org.apache.commons.cli.Options
+
+
+data class WrongArgumentError(
+        val message: String,
+        val cause: Throwable? = null,
+        val cmdLineOptionsList: List<CommandLineOption>) {
+
+    constructor(par: Throwable, cmdLineOptionsList: List<CommandLineOption>) :
+            this(par.message ?: "",
+                    par,
+                    cmdLineOptionsList)
+
+    fun printMessage() {
+        println(message)
+    }
+
+    fun printHelp(programName: String) {
+        val formatter = HelpFormatter()
+        val footer = "All parameters can be specified as environment variables using upper-snake-case full " +
+                "name with prefix `VESHV_`."
+
+        formatter.printHelp(
+                programName,
+                generateRequiredParametersNote(cmdLineOptionsList),
+                getOptions(),
+                footer)
+    }
+
+    private fun getOptions() = cmdLineOptionsList.map { it.option }.fold(Options(), Options::addOption)
+
+    companion object {
+        fun generateRequiredParametersNote(cmdLineOptionsList: List<CommandLineOption>): String {
+            val requiredParams = Option.fromNullable(cmdLineOptionsList.filter { it.required }
+                    .takeUnless { it.isEmpty() })
+            return requiredParams.fold(
+                    { "" },
+                    {
+                        it.map { commandLineOption -> commandLineOption.option.opt }
+                                .joinToString(prefix = "Required parameters: ", separator = ", ")
+                    }
+            )
+        }
+    }
+
+}
+
diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/extensions.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/extensions.kt
new file mode 100644
index 00000000..a8414472
--- /dev/null
+++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/commandline/extensions.kt
@@ -0,0 +1,66 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.utils.commandline
+
+import arrow.core.Option
+import arrow.core.getOrElse
+import arrow.effects.IO
+import arrow.syntax.function.curried
+import org.apache.commons.cli.CommandLine
+import org.onap.dcae.collectors.veshv.utils.arrow.ExitFailure
+import org.onap.dcae.collectors.veshv.utils.arrow.fromNullablesChain
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since June 2018
+ */
+
+fun handleWrongArgumentError(programName: String, err: WrongArgumentError): IO<Unit> = IO {
+    err.printMessage()
+    err.printHelp(programName)
+}.flatMap { ExitFailure(2).io() }
+
+val handleWrongArgumentErrorCurried = ::handleWrongArgumentError.curried()
+
+fun CommandLine.longValue(cmdLineOpt: CommandLineOption, default: Long): Long =
+        longValue(cmdLineOpt).getOrElse { default }
+
+fun CommandLine.stringValue(cmdLineOpt: CommandLineOption, default: String): String =
+        optionValue(cmdLineOpt).getOrElse { default }
+
+fun CommandLine.intValue(cmdLineOpt: CommandLineOption, default: Int): Int =
+        intValue(cmdLineOpt).getOrElse { default }
+
+fun CommandLine.intValue(cmdLineOpt: CommandLineOption): Option<Int> =
+        optionValue(cmdLineOpt).map(String::toInt)
+
+fun CommandLine.longValue(cmdLineOpt: CommandLineOption): Option<Long> =
+        optionValue(cmdLineOpt).map(String::toLong)
+
+fun CommandLine.stringValue(cmdLineOpt: CommandLineOption): Option<String> =
+        optionValue(cmdLineOpt)
+
+fun CommandLine.hasOption(cmdLineOpt: CommandLineOption): Boolean =
+        this.hasOption(cmdLineOpt.option.opt) ||
+                System.getenv(cmdLineOpt.environmentVariableName()) != null
+
+private fun CommandLine.optionValue(cmdLineOpt: CommandLineOption) = Option.fromNullablesChain(
+        getOptionValue(cmdLineOpt.option.opt),
+        { System.getenv(cmdLineOpt.environmentVariableName()) })
diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/http/http.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/http/http.kt
new file mode 100644
index 00000000..c5c46397
--- /dev/null
+++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/http/http.kt
@@ -0,0 +1,81 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.utils.http
+
+import arrow.typeclasses.Show
+import java.util.*
+import javax.json.Json
+
+/**
+ * @author Jakub Dudycz <jakub.dudycz@nokia.com>
+ * @since August 2018
+ */
+object HttpConstants {
+    const val STATUS_OK = 200
+    const val STATUS_ACCEPTED = 202
+    const val STATUS_BAD_REQUEST = 400
+    const val STATUS_NOT_FOUND = 404
+    const val STATUS_INTERNAL_SERVER_ERROR = 500
+    const val STATUS_SERVICE_UNAVAILABLE = 503
+
+    const val CONTENT_TYPE_JSON = "application/json"
+    const val CONTENT_TYPE_TEXT = "text/plain"
+}
+
+enum class HttpStatus(val number: Int) {
+    OK(HttpConstants.STATUS_OK),
+    ACCEPTED(HttpConstants.STATUS_ACCEPTED),
+    BAD_REQUEST(HttpConstants.STATUS_BAD_REQUEST),
+    NOT_FOUND(HttpConstants.STATUS_NOT_FOUND),
+    INTERNAL_SERVER_ERROR(HttpConstants.STATUS_INTERNAL_SERVER_ERROR),
+    SERVICE_UNAVAILABLE(HttpConstants.STATUS_SERVICE_UNAVAILABLE)
+}
+
+
+enum class ContentType(val value: String) {
+    JSON(HttpConstants.CONTENT_TYPE_JSON),
+    TEXT(HttpConstants.CONTENT_TYPE_TEXT)
+}
+
+data class Response(val status: HttpStatus, val content: Content<Any>)
+data class Content<T>(val type: ContentType, val value: T, val serializer: Show<T> = Show.any())
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since September 2018
+ */
+object Responses {
+
+    fun acceptedResponse(id: UUID): Response {
+        return Response(
+                HttpStatus.ACCEPTED,
+                Content(ContentType.TEXT, id)
+        )
+    }
+
+    fun statusResponse(name: String, message: String, httpStatus: HttpStatus = HttpStatus.OK): Response {
+        return Response(httpStatus,
+                Content(ContentType.JSON,
+                        Json.createObjectBuilder()
+                                .add("status", name)
+                                .add("message", message)
+                                .build()))
+    }
+}
diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/http/ratpack.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/http/ratpack.kt
new file mode 100644
index 00000000..0282d0c7
--- /dev/null
+++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/http/ratpack.kt
@@ -0,0 +1,77 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.utils.http
+
+import arrow.core.Either
+import arrow.effects.IO
+import org.onap.dcae.collectors.veshv.utils.logging.Logger
+import javax.json.Json
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since August 2018
+ */
+
+private val logger = Logger("org.onap.dcae.collectors.veshv.utils.arrow.ratpack")
+
+fun ratpack.http.Response.sendOrError(action: IO<Unit>) {
+    sendAndHandleErrors(action.map {
+        Response(
+                HttpStatus.OK,
+                Content(
+                        ContentType.JSON,
+                        Json.createObjectBuilder().add("response", "Request accepted").build()))
+    })
+}
+
+fun <A> ratpack.http.Response.sendEitherErrorOrResponse(response: Either<A, Response>) {
+    when(response) {
+        is Either.Left -> send(errorResponse(response.a.toString()))
+        is Either.Right -> sendAndHandleErrors(IO.just(response.b))
+    }
+}
+
+fun ratpack.http.Response.sendAndHandleErrors(response: IO<Response>) {
+    response.attempt().unsafeRunSync().fold(
+            { err ->
+                logger.warn("Error occurred. Sending .", err)
+                val message = err.message
+                send(errorResponse(message))
+            },
+            ::send
+    )
+}
+
+private fun errorResponse(message: String?): Response {
+    return Response(
+            HttpStatus.INTERNAL_SERVER_ERROR,
+            Content(
+                    ContentType.JSON,
+                    Json.createObjectBuilder().add("error", message).build()))
+}
+
+fun ratpack.http.Response.send(response: Response) {
+    val respWithStatus = status(response.status.number)
+    response.content.apply {
+        respWithStatus.send(
+                type.value,
+                serializer.run { value.show() })
+    }
+}
diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/logging/Logger.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/logging/Logger.kt
new file mode 100644
index 00000000..033dd5e5
--- /dev/null
+++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/logging/Logger.kt
@@ -0,0 +1,137 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.utils.logging
+
+import kotlin.reflect.KClass
+import org.slf4j.LoggerFactory
+
+@Suppress("TooManyFunctions", "SuboptimalLoggerUsage")
+class Logger(val logger: org.slf4j.Logger) {
+    constructor(clazz: KClass<out Any>) : this(LoggerFactory.getLogger(clazz.java))
+    constructor(name: String) : this(LoggerFactory.getLogger(name))
+
+    //
+    // TRACE
+    //
+
+    val traceEnabled: Boolean
+        get() = logger.isTraceEnabled
+
+    fun trace(messageProvider: () -> String) {
+        if (logger.isTraceEnabled) {
+            logger.trace(messageProvider())
+        }
+    }
+
+    //
+    // DEBUG
+    //
+
+    fun debug(message: String) {
+        logger.debug(message)
+    }
+
+    fun debug(message: String, t: Throwable) {
+        logger.debug(message, t)
+    }
+
+    fun debug(messageProvider: () -> String) {
+        if (logger.isDebugEnabled) {
+            logger.debug(messageProvider())
+        }
+    }
+
+    fun debug(t: Throwable, messageProvider: () -> String) {
+        if (logger.isDebugEnabled) {
+            logger.debug(messageProvider(), t)
+        }
+    }
+
+    //
+    // INFO
+    //
+    fun info(message: String) {
+        logger.info(message)
+    }
+
+    fun info(messageProvider: () -> String) {
+        if (logger.isInfoEnabled) {
+            logger.info(messageProvider())
+        }
+    }
+
+    fun info(message: String, t: Throwable) {
+        logger.info(message, t)
+    }
+
+    fun info(t: Throwable, messageProvider: () -> String) {
+        if (logger.isInfoEnabled) {
+            logger.info(messageProvider(), t)
+        }
+    }
+
+    //
+    // WARN
+    //
+
+    fun warn(message: String) {
+        logger.warn(message)
+    }
+
+    fun warn(message: String, t: Throwable) {
+        logger.warn(message, t)
+    }
+
+    fun warn(messageProvider: () -> String) {
+        if (logger.isWarnEnabled) {
+            logger.warn(messageProvider())
+        }
+    }
+
+    fun warn(t: Throwable, messageProvider: () -> String) {
+        if (logger.isWarnEnabled) {
+            logger.warn(messageProvider(), t)
+        }
+    }
+
+    //
+    // ERROR
+    //
+
+    fun error(message: String) {
+        logger.error(message)
+    }
+
+    fun error(message: String, t: Throwable) {
+        logger.error(message, t)
+    }
+
+    fun error(messageProvider: () -> String) {
+        if (logger.isErrorEnabled) {
+            logger.error(messageProvider())
+        }
+    }
+
+    fun error(t: Throwable, messageProvider: () -> String) {
+        if (logger.isErrorEnabled) {
+            logger.error(messageProvider(), t)
+        }
+    }
+}
diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/logging/reactive_logging.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/logging/reactive_logging.kt
new file mode 100644
index 00000000..714702d3
--- /dev/null
+++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/logging/reactive_logging.kt
@@ -0,0 +1,28 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.utils.logging
+
+import reactor.core.publisher.Flux
+
+fun <T> Logger.handleReactiveStreamError(ex: Throwable, returnFlux: Flux<T> = Flux.empty()): Flux<T> {
+    logger.warn("Error while handling message stream: ${ex::class.qualifiedName} (${ex.message})")
+    logger.debug("Detailed stack trace", ex)
+    return returnFlux
+}
diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/server_handle.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/server_handle.kt
new file mode 100644
index 00000000..bdb63b68
--- /dev/null
+++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/server_handle.kt
@@ -0,0 +1,46 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.utils
+
+import arrow.effects.IO
+import reactor.netty.DisposableServer
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since August 2018
+ */
+abstract class ServerHandle(val host: String, val port: Int) {
+    abstract fun shutdown(): IO<Unit>
+    abstract fun await(): IO<Unit>
+}
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since August 2018
+ */
+class NettyServerHandle(private val ctx: DisposableServer) : ServerHandle(ctx.host(), ctx.port()) {
+    override fun shutdown() = IO {
+        ctx.disposeNow()
+    }
+
+    override fun await() = IO<Unit> {
+        ctx.channel().closeFuture().sync()
+    }
+}