Proposal: Align jib-maven-plugin configuration with jib-gradle-plugin

Implemented in: v0.9.0

Motivation

jib-gradle-plugin introduced a different configuration schema from jib-maven-plugin. This schema has many benefits over the original jib-maven-plugin configuration. Therefore, to maintain consistency between the two plugins, the jib-maven-plugin configuration should be updated to be more similar to the jib-gradle-plugin configuration.

Goals

• Have jib-maven-plugin configuration be as similar to jib-gradle-plugin configuration as possible

Non-Goals

• Maintain compatibility with older versions of jib-maven-plugin (we are still in alpha)

Current Configuration Schema

The current jib-maven-plugin configuration looks like:

<configuration>
  <from>openjdk:alpine</from>
  <registry>localhost:5000</registry>
  <repository>my-image</repository>
  <tag>built-with-jib</tag>
  <credHelpers>
    <credHelper>osxkeychain</credHelper>
  </credHelpers>
  <jvmFlags>
    <jvmFlag>-Xms512m</jvmFlag>
    <jvmFlag>-Xdebug</jvmFlag>
    <jvmFlag>-Xmy:flag=jib-rules</jvmFlag>
  </jvmFlags>
  <mainClass>mypackage.MyApp</mainClass>
  <enableReproducibleBuilds>true</enableReproducibleBuilds>
  <imageFormat>OCI</imageFormat>
</configuration>

And the current jib-gradle-plugin configuration looks like:

jib {
  from {
    image = 'openjdk:alpine'
  }
  to {
    image = 'localhost:5000/my-image/built-with-jib'
    credHelper = 'osxkeychain'
  }
  jvmFlags = ['-Xms512m', '-Xdebug', '-Xmy:flag=jib-rules']
  mainClass = 'mypackage.MyApp'
  reproducible = true
  format = 'OCI'
}

Desired Configuration Schema

Therefore, the desired jib-maven-plugin configuration should look like:

<configuration>
  <from>
    <image>openjdk:alpine</image>
  </from>
  <to>
    <image>gcr.io/my-gcp-project/my-app</image>
    <credHelper>gcr</credHelper>
  </to>
  <jvmFlags>
    <jvmFlag>-Xmy:flag=jib-rules</jvmFlag>
  </jvmFlags>
  <mainClass>mypackage.MyApp</mainClass>
  <reproducible>true</reproducible>
  <format>OCI</format>
</configuration>

The key changes are:

• Removes registry, repository, and tag - these are now defined as one field to.image.
• Adds an image configuration object that takes:
  • to - the image reference, and
  • credHelper - the credential helper for that image
• The image configuration object configures both the base image (from) and the target image (to).
• enableReproducibleBuilds is renamed to reproducible.
• imageFormat is renamed to format.

Implementation Details

1. Change BuildConfiguration to individual credHelpers for the base and target images, not as a list.
2. Change the BuildImageMojo (and DockerContextMojo) schema.

• The only required field now is to.image.