使用sbt-native-packager构建含Gatling的Scala项目Docker镜像遇异常

我正尝试使用sbt-native-packager为包含Gatling负载测试的Scala项目构建Docker镜像。Gatling负载测试可正常运行，但执行docker:publishLocal命令构建镜像时，抛出java.lang.IllegalArgumentException异常，提示“Couldn't locate Gatling libraries in the classpath”。

相关配置 #

build.sbt #

ThisBuild / version := "0.1.0-SNAPSHOT"

ThisBuild / scalaVersion := "2.13.4"

ThisBuild / scapegoatVersion := "1.4.8"


lazy val root = (project in file("."))
  .settings(
    name := "face-recognition"
  )

enablePlugins(GatlingPlugin, JavaAppPackaging, DockerPlugin, ScoverageSbtPlugin)
Docker / packageName := "face-recognition"

Docker / version := "0.0.1"
dockerExposedPorts := Seq(8080)

dockerChmodType := DockerChmodType.UserGroupWriteExecute
dockerPermissionStrategy := DockerPermissionStrategy.CopyChown
dockerAdditionalPermissions += (DockerChmodType.UserGroupPlusExecute, "/var/run/")

Docker / daemonUserUid := None
Docker / daemonUser := "root"

dockerBaseImage := "amazoncorretto:11-alpine3.18-jdk"

libraryDependencies ++= Seq(
"io.gatling.highcharts" % "gatling-charts-highcharts" % "3.9.1" % "test",
  "io.gatling" % "gatling-test-framework" % "3.9.1" % "test",
  "com.typesafe.akka" %% "akka-slf4j" % "2.8.0",
  "io.gatling" % "gatling-http" % "3.5.1"
)

plugin.sbt #

addSbtPlugin("io.gatling" % "gatling-sbt" % "4.2.6")

错误信息 #

[error] stack trace is suppressed; run last Gatling-it / enterprisePackage for the full output
[error] (Gatling-it / enterprisePackage) java.lang.IllegalArgumentException: Couldn't locate Gatling libraries in the classpath

解决方案 #

1. 统一Gatling依赖版本 #

当前配置中gatling-http版本为3.5.1，与其他Gatling依赖的3.9.1版本不一致，这会导致类路径依赖冲突或缺失。将所有Gatling依赖版本统一为3.9.1：

libraryDependencies ++= Seq(
  "io.gatling.highcharts" % "gatling-charts-highcharts" % "3.9.1" % "test",
  "io.gatling" % "gatling-test-framework" % "3.9.1" % "test",
  "com.typesafe.akka" %% "akka-slf4j" % "2.8.0",
  "io.gatling" % "gatling-http" % "3.9.1" // 统一版本
)

2. 调整Gatling依赖作用域或禁用不必要的任务 #

• 如果你的Docker镜像需要运行Gatling测试，将Gatling核心依赖从test作用域改为compile，确保打包时包含这些依赖：

libraryDependencies ++= Seq(
  "io.gatling.highcharts" % "gatling-charts-highcharts" % "3.9.1",
  "io.gatling" % "gatling-test-framework" % "3.9.1",
  "com.typesafe.akka" %% "akka-slf4j" % "2.8.0",
  "io.gatling" % "gatling-http" % "3.9.1"
)

• 如果只是打包应用，不需要在Docker构建过程中触发Gatling的enterprisePackage任务，直接禁用该任务：

// 禁用Gatling的enterprisePackage任务，避免构建Docker时触发
Gatling / enterprisePackage := {}
Gatling-it / enterprisePackage := {}

3. 确保打包时包含必要的测试依赖（如果需要） #

如果Docker镜像需要包含测试代码和依赖，配置sbt-native-packager将Test作用域的内容加入打包：

// 将Test作用域的映射添加到Universal打包中
mappings in Universal ++= (mappings in Test).value
// 确保Test依赖被包含
dependencyClasspath in Universal ++= (dependencyClasspath in Test).value

内容的提问来源于stack exchange，提问作者Asif khAn