NPE during Preconditions validation

[vgalloy]

Environment:

• Jib version: 2.5.0
• Build tool: gradle 6.6
• OS: Ubuntu 20.04.1 LTS
• Java: openjdk version "14" 2020-03-17

Description of the issue:
ImmutableCollections#contains(Object) throw a NullPointerException if the argument is null. Checking if collection contains null will always throw a NullPointerException
Example
Arrays.asList("java").contains(null) => false
List.of("java").contains(null) => NullPointerException

There is several place where the following pattern is apply :
Preconditions.checkArgument(!entrypoint.contains(null), "entrypoint contains null elements");

Passing an ImmutableCollections as entrypoint always fail

Expected behavior:
No NullPointerException exception

Steps to reproduce:

1. ./gradlew jibDockerBuild

jib-gradle-plugin Configuration:

plugins {
  id 'java-library'
  id 'com.google.cloud.tools.jib' version '2.5.0'
}

java {
  targetCompatibility = JavaVersion.VERSION_11
  sourceCompatibility = JavaVersion.VERSION_11
}

jib {
  container {
    entrypoint = List.of('java', '-jar', 'my-jar')
  }
}

Log output:

Caused by: java.lang.NullPointerException
        at com.google.cloud.tools.jib.configuration.ContainerConfiguration$Builder.setEntrypoint(ContainerConfiguration.java:265)
        at com.google.cloud.tools.jib.api.JibContainerBuilder.setEntrypoint(JibContainerBuilder.java:274)
        at com.google.cloud.tools.jib.plugins.common.PluginConfigurationProcessor.processCommonConfiguration(PluginConfigurationProcessor.java:403)
        at com.google.cloud.tools.jib.plugins.common.PluginConfigurationProcessor.processCommonConfiguration(PluginConfigurationProcessor.java:455)
        at com.google.cloud.tools.jib.plugins.common.PluginConfigurationProcessor.createJibBuildRunnerForDockerDaemonImage(PluginConfigurationProcessor.java:132)
        at com.google.cloud.tools.jib.gradle.BuildDockerTask.buildDocker(BuildDockerTask.java:110)

Additional Information:
I know that not a conventional way to write a List, I'm just trying to provided the shorter possible example.

[loosebazooka]

so the contains method cannot handle null on the specific implementation of List?

This is a good catch.

[loosebazooka]

@mpeddada1 can you look into this bug?

[mpeddada1]

@vgalloy We've released Jib 2.6.0, which contains a fix for this issue. Thanks for reporting!