Apache Way

A recording of the webinar about Apache Software Process:

JIRA Process

Getting Started

• Easy tickets to get started with Apache Ignite: easy tickets
• All other issues: Ignite Jira

Tickets and Versions

Tickets are picked up by community members from a pool of unassigned and unscheduled tickets after discussion on project's dev list. Assigning tickets to a version contributor helps others to understand what will be included in next release.

JIRA issues are grouped by fixVersion field, which is an intended version of the product feature gets merged to. Everyone should make sure that after closing fixVersion is set to a proper version that actually releases the changes made in scope of the ticket.

The following page contains information on upcoming releases (draft) Release Plan.

Ticket Creation

• Every JIRA ticket should be sufficiently described. 
• There should not be any tickets with title only and without description. 
• If there is a discussion pertaining to the ticket, the ticket should have a link to the dev list.

Beginning Work

• Anyone in the community can start working on any unassigned ticket. 
• (OPTIONAL) It is recommended to clarify the relevance and correctness of the ticket in the community before doing actual implementation. To do this, you can write an email to the dev.list and wait for answer.
• Before beginning working on a ticket, you should assign the ticket to yourself.
• Move the ticket to IN PROGRESS state.
• If necessary, add comments describing the design decisions or approach you plan to take.

Review Process and Maintainers

• Ignite employs both Review-Then-Commit (RTC) process for most of the components and Commit-Then-Review (CTR) for few ones.
• Any change that touches code or test, whether reviewed or not, must have full TeamCity CI test suite pass.
• As a guideline, trivial changes, like updates to documentation or tests, etc. should not need a review prior to committing, and often can be made directly in the master branch.
  
  

Changes to a RTC module should be reviewed at least by one maintainer for that module (which may or may not be the same as the main reviewer) before being merged.

Changes to a CTR module (CTR*) may be merged without waiting for review by a maintainer. However it's advisable to ask a maintainer of a CTR module for review and to wait for some time for his/her feedback.

Submitting for Review

• Attach a patch, pull request url or branch name (see instructions at Workflow)
• (OPTIONAL) create an Upsource review: Review With Upsource
• Add comment describing what has been implemented.
• Move ticket to PATCH AVAILABLE state.

Reviewing a Ticket

• Each comment should be started with [~username] to guarantee proper notification.
• Commiter should add comment like "Changes accepted and ready to be merged." once review successfully finished.
• If the commiter/contributor has proposals, it is recommended to add a comment in the ticket in addition to PR / CR comments referring proposals added. This helps other committers to identify that fix has something to improve.

Closing a Ticket

• Once ticket has passed all the reviews and has no additional comments, a committer should apply the latest patch to the master branch.
• A comment should be added to the ticket stating that the patch has been applied to master.
• Move ticket to RESOLVED state. 

Review With Upsource

Upsource is an online code review tool. It provides a convenient way to view and discuss changes.

Upsource is optional: it is up to author and reviewer whether to use it or not. Big changes with long discussions are easier to manage in Upsource.

Code author workflow:

• Register on http://reviews.ignite.apache.org/
• Go to Branches view: http://reviews.ignite.apache.org/ignite/branches
• Click on your pull request ("PR XXXX"). Upsource can take up to 1 minute to discover new pull request.
• Click "Create branch review"
• Rename review to include JIRA key and description (example: "IGNITE-42 Support CacheLoader and CacheWriter")
• In JIRA, use More -> Link -> Web Link to link the review page
• New changes in the pull request are picked up automatically (may take a minute)

Reviewer workflow:

• Follow the Upsource link in JIRA
• Select files on the left to view changes
• Click on line numbers to leave comments
• Leave general comments on the timeline screen
• Addressed comments may be marked as "Resolved"
• When all issues are resolved (if any), click "Accept" on the top left, and leave a comment in JIRA
  
  

Git Process

Apache Ignite community agreed to release new version at least once per quarter. However, duration may be longer or shorter. After development of new functionality is finished, QA cycle starts, then release procedure follows.

Overview

• Master should become the development branch for the next release.
• Whenever current release goes to QA, new branch should be created from master. This way master can be used to develop functionality of the next release. All release fixes get merged to release branch and then to master.
• All individual ticket/features development happen in separate repositories (either local or forks of GitHub mirror - https://github.com/apache/ignite) . Firm rule: ticket/feature branches should never be pushed to repo. 
• Development  branches should be created off of the master branch (or release branch if one exists - in this case changes get merged to release branch and then to master branch). Changes get merged to master branch of the project Git via process described at Workflow.
• Git tag should be created for every release.
• All CI tests must pass before the merge of ticket branches to the master (or release) branch.

Normally, project repo should contain only master branch, very few branches for ongoing releases and commiter's branches ready to be reviewed. Committers and PMC members are in charge to make everyone follow this rule.

Release Process

Instructions on how to build source and binary releases can be found at DEVNOTES.txt. Please see "Ignite Release Instructions" section. On how to make official release please refer to Release Process.

Workflow

There are 3 way how you can make contribution

1. GitHub pull-request
2. Patch-file
3. Ticket Branch (only committers)

1. Create GitHub pull-request

 +------------+             +---------------+            +-----------------+

 |            |   replica   |               |    fork    |                 |

 | Apache Git | ==========> | GitHub Mirror | ---------> | John Doe's Fork |

 |            |             |               |            |                 |

 +------------+             +---------------+            +-----------------+

        ^                            ^                            ^

        |                            |                            |

        |                            +------------------------+   | origin

        |                                  upstream           |   |

        |                                                     |   |

        |                                                +-----------------+

        |    *Apache Git remote handle for committers*   |                 |

        +------------------------------------------------|   Local clone   |

                                                         |                 |

                                                         +-----------------+

Creation

To start:

• You need to fork an Apache Ignite mirror on GitHub.
• Make a local copy of your Apache Ignite mirror fork. Your remote origin will refer to 'https://github.com/<your_github_uname>/ignite.git'.

• You will need to update a local master sometimes (to merge to your development branches sometimes). How to do it:

  • Add remote for Apache Ignite mirror (you need to do it once)

    git remote add upstream https://github.com/apache/ignite.git

  • Each time when you want to update your local master do the following:

    git pull upstream
    git checkout master

To make contribution:

• Fix / implement JIRA ticket in your fork. Provide Java docs whenever required. If you add a new package make sure that package-info.java file in it is in place with a description. Commit branch to origin (origin = your fork). It's recommended to develop IGNITE-xxx ticket at ignite-xxx branch.
• If your contribution is significant (new functionality, deeply reworked existed functionality API) then add an example of usage to 'ignite-example' and add an article to Apache Ignite Documentation.
• Create pull request from the new remote branch in the fork to master of Apache Ignite mirror. Please, start a title of the pull request from 'IGNITE-xxx'. An email about the pull request will be send to dev-list and the same JIRA comment will be added to the IGNITE-xxx ticket.
• Trigger validation of those test suites that have been affected by your changes on TeamCity:
  • Locate a test suite you have to check, press button named "..." that is located on the left of "Run" button. "Run custom build" dialog will appear;
  • Go to "Changes" tab and choose "pull/<pull-request-number>/head" in "Build branch" dropdown list;
  • Press "Run build" button and monitor tests results. 
• Once tests are passed, the pull request can be reviewed and merged by a committer. Move a corresponding JIRA ticket to "Patch Available" state by clicking on "Submit Patch" button and let the community know that you're ready for review.
  
  

Applying

In additional to contributors configuration, committers need to have one more remote reoi - for working with Apache Git repo. It can be added like this:

• git remote add apache https://git-wip-us.apache.org/repos/asf/ignite

To push any branch at Apache repo use

• git push apache <branch_name>

To apply a pull-request it's strongly recommended using ./scripts/apply-pull-request.sh script. Script takes 'pull-request-id' as a parameter and do next:

2. Create a Patch-file

Creation

You can start by cloning the Ignite GIT repo.

We use git as our version control system. To streamline the process of giving proper credit to the contributors when committing patches, we encourage contributors to submit patches generated using "git format-patch" command. This has many benefits:

• Committers will not forget to give proper credit to a contributor
• Contributor's name and email address show up in the git log

Long story short, it makes both the contributors' and committers' lives easier, so please generate your patches using git format-patch.

We have the following requirements for patches:

• patch can be applied to the HEAD of 'master' branch by "git am <patch-file>" without conflicts.
  
• patch has to have all changes in one commit with comment like "ignite-xxx: Implemented."
• patch-file has to have 'patch', 'txt' or 'diff' extension

Patch Creation Process

We prefer that you use the following step-by-step instructions when developing with Ignite.

For example, if you are starting working on the feature IGNITE-9999.

## Get the repo
git clone https://github.com/apache/incubator-ignite.git
## Some development here with many commits at ignite-9999.
git commit -a -m 'ignite-9999: Intermediate commit 1';
...
git commit -a -m 'ignite-9999: Intermediate commit 100';


## Commit the last changes.
git commit -a -m 'ignite-9999: Implemented.';


## Making patch.
## There are a lot of changes at ignite-sprint-999 and we need to get it, resolve conflicts (if exists), rerun tests for ignite-9999. 
git checkout master 
git pull  
git checkout ignite-9999 
git merge master

## Run script to make patch. Patch will have all changes as one commit.
<ignite_home>/scripts/git-format-patch.sh

Note: it is strongly recommended to merge 'master' branch to your development branch, for example, every day (or after each commit).

Patch Validation

Created patch-file should be attached to a JIRA ticket and the ticket status should be changed on Patch Available.

If you do everything correctly, then all necessary TeamCity test builds will be triggered automatically in 3 minutes period, and a comment with triggered build information (test package names, TeamCity build links) will be added to the JIRA.

Once tests are passed, the patch can be reviewed and merged by a committer.

Requirements (to auto triggering the test builds):

• patch-file has to have 'patch', 'txt' or 'diff' extension
• patch-file has to be attached by JIRA user with contributor role.

Applying

Contributor patches have to be applied by next command.

git am -s <patch-file>

This command apply a patch file generated by 'git format-patch', stores information who created a patch and who applied a patch. So, it gives proper credit to the contributor and store an information who decide to take these changes.

If patch file has been created by scripts/git-format-patch.sh then a name of a patch-file contains a short hash revision of master branch revision against which patch has been created. Patch file template is 

master_<hash>_ignite-<ticket-number>.patch

For example

master_b001525_ignite-9999.patch

So, in case, if a patch can't be applied without conflicts on the HEAD of master and the patch has been created by scripts/git-format-patch.sh then a commiter can apply the patch to master by a revision hash, review changes and resolve the conflicts by yourself.

3. Create a Ticket Branch (only committers)

Creation & Applying

Whenever working on bigger features, committers can also create 'ready to be reviewed' branch ignite-XXXX, where XXXX is the number of the JIRA ticket.

TeamCity should be forced to run all tests on created branch before review. Once tests are passed, the branch has be reviewed by module's maintainer.

Created branch name should be attached to a JIRA ticket and the ticket status should be changed on Patch Available.

Branch can be merged to master on sucessful review by at least one another committer.

Branch should be deleted on branch merged to master or issue cancelled. Committers are in charge of deleting their branches.  

Checklist before push

List of points should be checked before push: 

Javadoc

Make sure project build log contains no javadoc warnings. Grep build output for "Javadoc Warnings". Covered by Licenses & Javadoc TeamCity task.

Readme

In case a new module is added, make sure it contains README.txt at the module's root.

Documentation & Examples

If the contribution is significant (new feature or significant rework of an existed functionality or API) make sure that an example is added to 'ignite-example' and/or an article is written for Apache Ignite Documentation.

Since readme.io does not automatically copy the changes from the current version to the subsequent version, documentation for any new feature that will be released in the next version should be created within the document for the current version. These new pages should be kept hidden until the next version released. 

Licenses

In case new module added, make sure source and binary distributions contains correct license files at modules folders. Covered by Licenses & Javadoc TeamCity task.

Can be checked manually by running command

mvn clean validate -DskipTests=true -P check-licenses

package-info.java

Make sure each package contains package-info.java with proper description.

Project Build

Make sure that command

mvn clean package -DskipTests

finishes without errors.