This project is currently stable, and we are primarily focused on critical bug fixes and platform evolution to ensure it continues to work for its supported use cases.

Contributing to Jib

Please follow the guidelines below before opening an issue or a PR:

1. Ensure the issue was not already reported.
2. Open a new issue if you are unable to find an existing issue addressing your problem. Make sure to include a title and clear description, as much relevant information as possible, and a code sample or an executable test case demonstrating the expected behavior that is not occurring.
3. Discuss the priority and potential solutions with the maintainers in the issue. The maintainers would review the issue and add a label "Accepting Contributions" once the issue is ready for accepting contributions.
4. Open a PR only if the issue is labeled with "Accepting Contributions", ensure the PR description clearly describes the problem and solution. Note that an open PR without an issues labeled with "Accepting Contributions" will not be accepted.

Contributor License Agreement

Contributions to this project must be accompanied by a Contributor License Agreement. You (or your employer) retain the copyright to your contribution; this simply gives us permission to use and redistribute your contributions as part of the project. Head over to https://cla.developers.google.com/ to see your current agreements on file or to sign a new one.

You generally only need to submit a CLA once, so if you've already submitted one (even if it was for a different project), you probably don't need to do it again.

Code Reviews

All submissions, including submissions by project members, require review. We use Github pull requests for this purpose.

Before submitting a pull request, please make sure to:

• Identify an existing issue to associate with your proposed change, or file a new issue.
• Describe any implementation plans in the issue and wait for a review from the repository maintainers.

Typical Contribution Cycle

1. Set your git user.email property to the address used for signing the CLA. E.g.

   git config --global user.email "janedoe@google.com"
   

   If you're a Googler or other corporate contributor, use your corporate email address here, not your personal address.
2. Fork the repository into your own Github account.
3. We follow our own Java style guide that extends the Google Java Style Guide.
4. Please include unit tests (and integration tests if applicable) for all new code.
5. Make sure all existing tests pass (but see the note below about integration tests).
   • run ./gradlew clean goJF build integrationTest
6. Associate the change with an existing issue or file a new issue.
7. Create a pull request!

Building Jib

Jib comes as 3 public components:

• jib-core: a library for building containers
• jib-maven-plugin: a Maven plugin that uses jib-core and jib-plugins-common
• jib-gradle-plugin: a Gradle plugin that uses jib-core and jib-plugins-common

And 1 internal component:

• jib-plugins-common: a library with helpers for maven/gradle plugins

The project is configured as a single gradle build. Run ./gradlew build to build the whole project. Run ./gradlew install to install all public components into the local maven repository.

Integration Tests

Note that in order to run integration tests, you will need to set one of the following environment variables:

• If you are using a GCP project then set JIB_INTEGRATION_TESTING_PROJECT to the GCP project to use for testing; the registry tested will be gcr.io/<JIB_INTEGRATION_TESTING_PROJECT>.
  • Configure authentication to Container Registry by following these steps.
  • Enable the Google Container Registry API here.
• If you're not using a GCP project then set JIB_INTEGRATION_TESTING_LOCATION to a specific registry for testing. (For example, you can run docker run -d -p 9990:5000 registry:2 to set up a local registry and set the variable to localhost:9990.)

You will also need Docker installed with the daemon running. Note that the integration tests will create local registries on ports 5000 and 6000.

To run select integration tests, use --tests=<testPattern>, see gradle docs for testPattern examples.

Development Tips

Java version

Use Java 8 or 11 for development. https://sdkman.io/ is a helpful tool to switch between Java versions.

Configuring Eclipse

Although jib is a mix of Gradle and Maven projects, we build everything using one unified gradle build. There is special code to include some projects directly as source, but importing your project should be pretty straight forward.

1. Ensure you have installed the Gradle tooling for Eclipse, called Buildship (available from the Eclipse Marketplace).
2. Import the Gradle project: Buildship does not yet support Eclipse Smart Import. Use File → Import → Gradle → Existing Gradle Project and import jib.

Note that you will likely need to re-apply these changes whenever you refresh or update these projects.

Debugging the Jib Maven Plugin (jib-maven-plugin)

Build and use a local snapshot

To use a local build of the jib-maven-plugin:

1. Build and install jib-maven-plugin into your local ~/.m2/repository with ./gradlew jib-maven-plugin:install;
2. Modify your test project's pom.xml to reference the -SNAPSHOT version of the com.google.cloud.tools.jib plugin.

If developing from within Eclipse with M2Eclipse (the Maven tooling for Eclipse):

1. Modify your test project's pom.xml to reference the -SNAPSHOT version of the com.google.cloud.tools.jib plugin.
2. Create and launch a Maven Build launch configuration for the test project, and ensure the Resolve Workspace artifacts is checked.

Attaching a debugger

Run mvnDebug jib:build and attach to port 8000.

If developing with Eclipse and M2Eclipse (the Maven tooling for Eclipse), just launch the Maven Build with Debug.

Debugging the Jib Gradle Plugin (jib-gradle-plugin)

Build and use a local snapshot

To use a local build of the jib-gradle-plugin:

1. Build and install jib-gradle-plugin into your local ~/.m2/repository with ./gradlew jib-gradle-plugin:install
2. Add a pluginManagement block to your test project's settings.gradle to enable reading plugins from the local maven repository. It must be the first block in the file before any include directives.

   pluginManagement {
     repositories {
       mavenLocal()
       gradlePluginPortal()
     }
   }
   

3. Modify your test project's build.gradle to use the latest snapshot version

   plugins {
     // id 'com.google.cloud.tools.jib' version 'major.minor.patch'
     id 'com.google.cloud.tools.jib' version 'major.minor.patch-SNAPSHOT'
   }
   
   

Attaching a debugger

Attach a debugger to a Gradle instance by running Gradle as follows:

./gradlew jib \
  --no-daemon \
  -Dorg.gradle.jvmargs='-agentlib:jdwp:transport=dt_socket,server=y,address=5005,suspend=y'