glusterdocs/docs/Developer-guide/Simplified-Development-Workflow.md

Simplified development workflow for GlusterFS
=============================================

This page gives a simplified model of the development workflow used by
the GlusterFS project. This will give the steps required to get a patch
accepted into the GlusterFS source.

Visit [Development Work Flow](./Development-Workflow.md) a more
detailed description of the workflow.

Initial preparation
-------------------

The GlusterFS development workflow revolves around
[GitHub](http://github.com/gluster/glusterfs/),
[Gerrit](http://review.gluster.org) and
[Jenkins](http://build.gluster.org).

Using these tools requires some initial preparation.

### Dev system setup

You should install and setup Git on your development system. Use your
distribution specific package manger to install git. After installation
configure git. At the minimum, set a git user email. To set the email
do,

```console
git config --global user.name <name>
git config --global user.email <email address>
```

You should also generate an ssh key pair if you haven't already done it.
To generate a key pair do,

```console
# ssh-keygen
```

and follow the instructions.

Next, install the build requirements for GlusterFS. Refer
[Building GlusterFS - Build Requirements](./Building-GlusterFS.md#Build Requirements)
for the actual requirements.

### Gerrit setup

To contribute to GlusterFS, you should first register on
[gerrit](http://review.gluster.org).

After registration, you will need to select a username, set a preferred
email and upload the ssh public key in gerrit. You can do this from the
gerrit settings page. Make sure that you set the preferred email to the
email you configured for git.

### Get the source

Git clone the GlusterFS source using

```console
<ssh://><username>@review.gluster.org/glusterfs.git
```

(replace <username> with your gerrit username).

```console
git clone (ssh://)<username> @review.gluster.org/glusterfs.git
```

This will clone the GlusterFS source into a subdirectory named glusterfs
with the master branch checked out.

It is essential that you use this link to clone, or else you will not be
able to submit patches to gerrit for review.

Actual development
------------------

The commands in this section are to be run inside the glusterfs source
directory.

### Create a development branch

It is recommended to use separate local development branches for each
change you want to contribute to GlusterFS. To create a development
branch, first checkout the upstream branch you want to work on and
update it. More details on the upstream branching model for GlusterFS
can be found at

[Development Work Flow - Branching\_policy](./Development-Workflow.md#branching-policy).
For example if you want to develop on the master branch,

```console
# git checkout master
# git pull
```

Now, create a new branch from master and switch to the new branch. It is
recommended to have descriptive branch names. Do,

```console
git branch <descriptive-branch-name>
git checkout <descriptive-branch-name>
```

or,

```console
git checkout -b <descriptive-branch-name>
```

to do both in one command.

### Hack

Once you've switched to the development branch, you can perform the
actual code changes. [Build](./Building GlusterFS) and test to
see if your changes work.

#### Tests

Unless your changes are very minor and trivial, you should also add a
test for your change. Tests are used to ensure that the changes you did
are not broken inadvertently. More details on tests can be found at

[Development Workflow - Test cases](./Development-Workflow.md#test-cases)
and
[Development Workflow - Regression tests and test cases](./Development-Workflow.md#regression-tests-and-test-cases)

### Regression test

Once your change is working, run the regression test suite to make sure
you haven't broken anything. The regression test suite requires a
working GlusterFS installation and needs to be run as root. To run the
regression test suite, do

```console
# make install
# ./run-tests.sh
```

### Commit your changes

If you haven't broken anything, you can now commit your changes. First
identify the files that you modified/added/deleted using git-status and
stage these files.

```console
git status
git add <list of modified files>
```

Now, commit these changes using

```console
# git commit -s
```

Provide a meaningful commit message. The commit message policy is
described at

[Development Work Flow - Commit policy](./Development-Workflow.md#commit-policy).

It is essential that you commit with the '-s' option, which will
sign-off the commit with your configured email, as gerrit is configured
to reject patches which are not signed-off.

### Submit for review

To submit your change for review, run the rfc.sh script,

```console
# ./rfc.sh
```

The script will ask you to enter an issue ID. Every change
submitted to GlusterFS needs a reference ID to be accepted. If you do
not already have a reference id, file a new issue in
[Github](https://github.com/gluster/glusterfs/issues/new). 
If the patch is submitted for review, the rfc.sh script will return the
gerrit url for the review request.

More details on the rfc.sh script are available at
[Development Work Flow - rfc.sh](./Development-Workflow.md#rfc.sh).

Review process
--------------

Your change will now be reviewed by the GlusterFS maintainers and
component owners on [gerrit](http://review.gluster.org). You can follow
and take part in the review process on the change at the review url. The
review process involves several steps.

To know component owners , you can check the "MAINTAINERS" file in root
of glusterfs code directory

### Automated verification

Every change submitted to gerrit triggers an initial automated
verification on [jenkins](http://build.gluster.org). The automated
verification ensures that your change doesn't break the build and has an
associated bug-id.

More details can be found at

[Development Work Flow - Auto verification](./Development-Workflow.md#auto-verification).

### Formal review

Once the auto verification is successful, the component owners will
perform a formal review. If they are okay with your change, they will
give a positive review. If not they will give a negative review and add
comments on the reasons.

More information regarding the review qualifiers and disqualifiers is
available at

[Development Work Flow - Submission Qualifiers](./Development-Workflow.md#submission-qualifiers)
and
[Development Work Flow - Submission Disqualifiers](./Development-Workflow.md#submission-disqualifiers).

If your change gets a negative review, you will need to address the
comments and resubmit your change.

#### Resubmission

Switch to your development branch and make new changes to address the
review comments. Build and test to see if the new changes are working.

Stage your changes and commit your new changes using,

```console
# git commit --amend
```

'--amend' is required to ensure that you update your original commit and
not create a new commit.

Now you can resubmit the updated commit for review using the rfc.sh
script.

The formal review process could take a long time. To increase chances
for a speedy review, you can add the component owners as reviewers on
the gerrit review page. This will ensure they notice the change. The
list of component owners can be found in the MAINTAINERS file present in
the GlusterFS source

### Verification

After a component owner has given a positive review, a maintainer will
run the regression test suite on your change to verify that your change
works and hasn't broken anything. This verification is done with the
help of jenkins.

If the verification fails, you will need to make necessary changes and
resubmit an updated commit for review.

### Acceptance

After successful verification, a maintainer will merge/cherry-pick (as
necessary) your change into the upstream GlusterFS source. Your change
will now be available in the upstream git repo for everyone to use.