ETCM-365: Put the version info into the client ID. Allow override fro…

…m properties.

src/main/resources/application.conf

@@ -1,6 +1,6 @@
 mantis {
-  # Identifier used when connecting to other clients
-  client-id = "mantis"
+  # Optionally override the client ID sent in Hello messages.
+  client-id = null
 
   # Version string (reported by an RPC method)
   client-version = "mantis/v2.0"

src/main/scala/io/iohk/ethereum/utils/Config.scala

@@ -23,7 +23,10 @@ object Config {
 
   val testmode: Boolean = config.getBoolean("testmode")
 
-  val clientId: String = config.getString("client-id")
+  val clientId =
+    ConfigUtils
+      .getOptionalValue(config, "client-id", _.getString("client-id"))
+      .getOrElse(VersionInfo.clientId)
 
   val clientVersion: String = config.getString("client-version")
 

src/main/scala/io/iohk/ethereum/utils/VersionInfo.scala

@@ -0,0 +1,34 @@
+package io.iohk.ethereum.utils
+
+object VersionInfo {
+
+  /** Produce a node name that get sent in `WireProtocol.Hello.clientId` according to Ethereum conventions.
+    *
+    * Check out examples on https://etcnodes.org
+    *
+    * e.g.
+    * - mantis/v3.0-cd5ae33/linux-amd64/ubuntu-openjdk64bitservervm-java-11.0.9
+    * - besu/v20.10.0/linux-x86_64/oracle_openjdk-java-11
+    * - coregeth/v1.11.8-stable-305b5089/linux-amd64/go1.14.4
+    */
+  val clientId = {
+    val appName = BuildInfo.name
+    val appVersion = BuildInfo.version
+    val appCommit = BuildInfo.gitHeadCommit.map("-" + _.take(7)).getOrElse("")
+
+    val osName = norm(prop("os.name"))
+    val osArch = norm(prop("os.arch"))
+
+    val javaVendor = norm(prop("java.vendor"))
+    val javaVmName = norm(prop("java.vm.name"))
+    val javaVersion = prop("java.version")
+
+    s"$appName/v$appVersion$appCommit/$osName-$osArch/$javaVendor-$javaVmName-java-$javaVersion"
+  }
+
+  private def prop(name: String) =
+    System.getProperty(name)
+
+  private def norm(value: String) =
+    value.toLowerCase.replaceAll("[^a-z0-9]+", "")
+}

src/test/resources/application.conf

@@ -1,7 +1,5 @@
 mantis {
 
-  client-id = "mantis"
-
   datadir = "/tmp/mantis-test/"
 
   secure-random-algo = "NativePRNGNonBlocking"

src/test/scala/io/iohk/ethereum/utils/ConfigSpec.scala

@@ -0,0 +1,10 @@
+package io.iohk.ethereum.utils
+
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+
+class ConfigSpec extends AnyFlatSpec with Matchers {
+  "clientId" should "by default come from VersionInfo" in {
+    Config.clientId shouldBe VersionInfo.clientId
+  }
+}

src/test/scala/io/iohk/ethereum/utils/VersionInfoSpec.scala

@@ -0,0 +1,12 @@
+package io.iohk.ethereum.utils
+
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+
+class VersionInfoSpec extends AnyFlatSpec with Matchers {
+  behavior of "clientId"
+
+  it should "preserve major and minor Java version" in {
+    VersionInfo.clientId should fullyMatch regex """.+/v\d.*-[a-z0-9]{7}/.+-.+/.+-.+-java-\d+\.\d+.*"""
+  }
+}