ActiveMQ6

This file describes some minimum 'stuff one needs to know' to get started coding in this project.

Source

The project's source code is hosted at:

https://git-wip-us.apache.org/repos/asf/activemq-6.git

Git usage:

Pull requests should be merged without fast forwards '--no-ff'. An easy way to achieve that is to use

% git config branch.master.mergeoptions --no-ff

Maven

The minimum required Maven version is 3.0.0.

Do note that there are some compatibility issues with Maven 3.X still unsolved 1. This is specially true for the 'site' plugin 2.

building the distribution

If you want to build the full release with documentation, Javadocs and the full web site then run the following:

% mvn -Prelease package

If you want to install it to your local maven repo then run

% mvn -Prelease install

The full release uses gitbook to build a static website from the documentation, if you don't have gitbook installed then install gitbook using npm

npm install -g gitbook

If you dont have npm installed then you would need to install that first, on Fedora this would be

yum install npm

It is possible to build a distribution with out the manuals and javadocs if you dont have or want gitbook installed, simply run

% mvn -Prelease distro

Tests

To run the unit tests:

% mvn -Phudson-tests test

Generating reports from unit tests:

% mvn install site

Running tests individually

% mvn -Phudson-tests -DfailIfNoTests=false -Dtest=<test-name> test

where <test-name> is the name of the Test class without its package name

Examples

To run an example firstly make sure you have run

% mvn -Prelease install

If the project version has already been released then this is unnecessary.

then you will need to set the following maven options, on Linux by

export MAVEN_OPTS="-Xmx1024m -XX:MaxPermSize=512m"

and the finally run the examples by

% mvn verify

You can also run individual examples by running the same command from the directory of which ever example you want to run. NB for this make sure you have installed examples/common.

Recreating the examples

If you are trying to copy the examples somewhere else and modifying them. Consider asking Maven to explicitly list all the dependencies:

# if trying to modify the 'topic' example:
cd examples/jms/topic && mvn dependency:list

Eclipse

We recommend using Eclipse Kepler (4.3), due to the built-in support for Maven and Git. Note that there are still some Maven plugins used by sub-projects (e.g. documentation) which are not supported even in Eclipse Kepler (4.3).

Eclipse m2e is already included in "Eclipse IDE for Java Developers", or it can be installed from Eclipse Kepler release repository.

Annotation Pre-Processing

ActiveMQ6 uses JBoss Logging and that requires source code generation from Java annotations. In order for it to 'just work' in Eclipse you need to install the Maven Integration for Eclipse JDT Annotation Processor Toolkit m2e-apt. See this JBoss blog post for details.

M2E Connector for Javacc-Maven-Plugin

Eclipse Indigo (3.7) has out-of-the-box support for it.

As of this writing, Eclipse Kepler (4.3) still lacks support for Maven's javacc plugin. The available m2e connector for javacc-maven-plugin requires a downgrade of Maven components to be installed. manual installation instructions (as of this writing you need to use the development update site). See this post for how to do this with Eclipse Juno (4.2).

The current recommended solution for Eclipse Kepler is to mark javacc-maven-plugin as ignored by Eclipse, run Maven from the command line and then modify the project activemq-core-client adding the folder target/generated-sources/javacc to its build path.

Use Project Working Sets

Importing all ActiveMQ6 subprojects will create too many projects in Eclipse, cluttering your Package Explorer and Project Explorer views. One way to address that is to use Eclipse's Working Sets feature. A good introduction to it can be found at a Dzone article on Eclipse Working Sets.

Code Formatting

Eclipse code formatting and (basic) project configuration files can be found at the etc/ folder. You should manually copy them after importing all your projects:

for settings_dir in `find . -type d -name .settings`; do
   \cp -v etc/org.eclipse.jdt.* $settings_dir
done

Do not use the maven-eclipse-plugin to copy the files as it conflicts with m2e.

Committing Changes

Repositories

The code repository for ActiveMQ6 is hosted by Apache org and lives here: https://git-wip-us.apache.org/repos/asf/activemq-6.git.

We also host a mirror of the ActiveMQ repository on GitHub: https://github.com/apache/activemq-6. We use this mirror for all code submissions and reviews. To submit code to ActiveMQ6 please open a Pull Request as outlined as part of the GitHub workflow described here: https://guides.github.com/introduction/flow/index.html. Once a pull request is opened it will be reviewed and commented on. Any further changes as a result of comments / review process should be addressed and reflected in the original pull request as outlined in the GitHub workflow. When the pull request has went through the review process and ready to merge, the reviewer should comment with "Ack, Ready to Push". Once an Ack message is received one of the ActiveMQ6 core team members will push the changes to upstream Apache ActiveMQ6 repository and close the pull request.

Commit Messages

We follow the 50/72 git commit message format. An ActiveMQ6 commit message should be formatted in the following manner:

• Add the ACTIVEMQ6 JIRA or Bugzilla reference (if one exists) followed by a brief description of the change in the first line.
• Insert a single blank line after the first line.
• Provide a detailed description of the change in the following lines, breaking paragraphs where needed.
• The first line should be limited to 50 characters
• Subsequent lines should be wrapped at 72 characters.

An example correctly formatted commit message:

ACTIVEMQ6-123 Add new commit msg format to README

Adds a description of the new commit message format as well as examples
of well formatted commit messages to the README.md.  This is required 
to enable developers to quickly identify what the commit is intended to 
do and why the commit was added.

Adding New Dependencies

Due to incompatibilities between some open source licenses and the Apache v2.0 license (that this project is licensed under) care must be taken when adding new dependencies to the project. The Apache Software Foundation 3rd party licensing policy has more information here: http://www.apache.org/legal/3party.html

To keep track of all licenses in ActiveMQ6, new dependencies must be added in either the top level pom.xml or in test/pom.xml (depending on whether this is a test only dependency or if it is used in the main code base). The dependency should be added under the dependency management section with version and labelled with a comment highlighting the license for the dependency version. See existing dependencies in the main pom.xml for examples. The dependency can then be added to individual ActiveMQ6 modules without the version specified (the version is implied from the dependency management section of the top level pom). This allows ActiveMQ6 developers to keep track of all dependencies and licenses.

Core Contributers

Core ActiveMQ6 members have write access to the Apache ActiveMQ6 repositories and will be responsible for Ack'ing and pushing commits contributed via pull requests on GitHub. The follow steps can be used as an example for how to set up relevant ActiveMQ6 repositories for reviewing and pushing changes.

To setup repositories for reviewing and pushing:

  # Clone the GitHub Mirror of ActiveMQ6 Repo:
  git clone git@github.com:apache/activemq-6.git

  # Add the following section to your <activemq6 repo>/.git/config statement to fetch all pull requests sent to the GitHub mirror.  Note that the remote name for git@github.com:apache/activemq-6.git may be different.  Be sure to edit all references to the remote name.  In this case "activemq".

  [remote "origin"]
        url = git@github.com:apache/activemq-6.git
        fetch = +refs/heads/*:refs/remotes/origin/*
        fetch = +refs/pull/*/head:refs/remotes/origin/pr/*


  # Add the Apache repository as a remote
  git remote add upstream https://git-wip-us.apache.org/repos/asf/activemq-6.git

  # Fetch
  git fetch --all

To push commits from a pull request to the apache repository:

  cd <activemq6 repo>

  # Download all the remote branches etc... including all the pull requests.
  git fetch --all
  
  # Checkout the pull request you wish to review
  git checkout pr/2

  # Review is done...  READY TO MERGE.

  # Check out the master branch.
  git checkout master

  # Ensure you are up to date
  git pull

  # Create a new merge commit from the 
  git merge --no-ff pr/2

  #  IMPORTANT: In this commit message be sure to write something along the lines of: "Merge Pull Request #2" Where 2 is the Pull Request ID.  "#2" shows up as a link in the GitHub UI for navigating to the PR from the commit message.

  # Pushes to the upstream repo.
  git push upstream master

Notes:

The GitHub mirror repository is cloning the Apache ActiveMQ6 repository (The root repository). There maybe a slight delay between when a commit is pushed to the Apache repo and when that commit is reflected in the GitHub mirror. This may cause some difficulty when trying to push a PR to upstream (Apache) that has been merged on an out of date GitHub (mirror) master. You can wait for the mirror to update before performing the steps above. A solution to this is to change local master branch to track the upstream (Apache) master, rather than GitHub (mirror) master by editing your config to look like this:

  [branch "master"]
        remote = upstream
        merge = refs/heads/master

Where upstream points to the Apache Repo.

If you'd like master to always track GitHub master, then another way to acheive this is to add another branch that tracks upstream master and push from that branch to upstream master e.g.

  # .git/config entry
  [branch "umaster"]
        remote = upstream
        merge = refs/heads/master

  git checkout umaster
  git pull
  git merge --no-ff pr/2
  git push upstream umaster:master # Push local branch umaster to upstream branch master.