This section describes a sample workflow for making and submitting changes to the project using
This section assumes that a developer has:
A developer should also be relatively comfortable with the shell.
The version control system used by the project is
git. Using git provides a developer with a way to cleanly keep track of and organize their changes, in addition to the ability (among many others) to view and reapply changes made to the code at various points in time. Importantly, git meshes in a way conducive to the ONOS code submission/review process; therefore, it is important for a potential contributor to be fairly comfortable with using it. Those interested in familiarizing themselves with git will find many resources online, including a full book.
As git is extremely rich in features, only the relevant functions will be mentioned where they are needed.
Create and switch to a new branch. A branch is a divergence point from the existing code base. Any changes made in a branch are restricted to the branch.
$ cd $ONOS_ROOT $ git checkout -b myBranch Switched to a new branch 'myBranch'
This creates a new branch named 'myBranch', off of the previous branch that we were in. Replace 'myBranch' with a name that briefly describes the topic of your change. This command will fail if there was already a branch of the same name. The command
git branch can be used to list all of the branches to check that the name isn't already used. If a branch with the desired name is no longer needed, it may be deleted with
git branch -D <branchName> and the above commands repeated to re-create a new branch.
git statusallows one to view the files that were modified.
git add <file>adds a file to the pool to commit. Once all files are added,
git commit -m "<message>"creates a snapshot with <message> as its description.
git logmay be used to list all of the commits that have been made, with the most recent commit at top.
Pull upstream changes. The repository on the development machine should be synchronized with the upstream ONOS source repository.
Upstream changes are always applied to the master branch. We first switch back to master with
git checkout, before pulling downloading the changes in the upstream source repository with
$ git checkout master Switched to branch 'master' $ git pull --ff-only origin master
Sync the branch with updated master. The updates pulled to master must be explicitly applied to the branch intended for code review. This is done by switching back to the development branch and using
$ git checkout myBranch Switched to branch 'myBranch' $ git rebase -i master
The default editor will be opened with the list of commits that have been made to the branch locally since its creation. Saving and closing this file causes the changes from the master branch to be incorporated into the branch. Any merge conflicts (e.g. a file modified in both the local and master branch) will interrupt the process. In
git status, the conflicting files will appear under "Unmerged paths" as "both modified". If this happens, the file(s) must be edited and committed before the rebase is continued:
$ git rebase -i master error: could not apply ca081b6... Initial commit for information persistence. $ vim core/net/src/main/java/org/onlab/onos/net/device/impl/DeviceManager.java $ git add core/net/src/main/java/org/onlab/onos/net/device/impl/DeviceManager.java $ git rebase --continue Successfully rebased and updated refs/heads/myBranch.
Submit code for review. Once the branch is synchronized, it may be submitted for review with
git review. (usage examples)
$ git review
This submits the changes with the branch name as its topic.
If you would like to change your code after submission, please follow the procedure as described in the "Amending Submissions" section below.
If you're using a Mac and git review command fails with an error traceback like below:
try upgrading the git-review package dependency first.
$ sudo pip install --upgrade setuptools
The review responses, and what they mean:
|-2||There is something fundamentally blocking about this check-in (e.g. style, design). It cannot be merged as is.|
|-1||Some issues require addressing. Please update and submit patchset (amend commit) for re-review.|
|0||A comment, with no opinion on whether or not to accept the change.|
|+1||Change looks good, but someone else must approve.|
|+2||Change looks good, approved.|
(Note that two +1's do not equal a +2)
Typically, if a module owner +2's a review, he/she will also submit (merge) the change also.
As part of the peer review process, an author of a patch submitted to Gerrit may be asked to amend their submission. To amend a patch:
Checkout the change. This creates a new branch for the changeset that represents this patch, with the naming convention review/submitter_name/branch_name.
$ git review -d 169
This needs to be done once for the changeset. If more amendments are needed for the patch later, one can simply check the branch out like any other:
$ git checkout review/[submitter_name]/[branch_name]
Make changes and commit. Here, we use
git commit --amend, instead of generating a new message.
$ git add [modified files] $ git commit --amend
Gerrit uses the Change-Id: ... in the commit comment to identify which changeset this commit belongs to.
Resubmit. This creates a new patchset on the existing review.
$ git review
If Gerrit returns an error about a missing Change-Id, make sure that there is a
Once finished and the patch is accepted, the branch can be deleted:
$ git branch -D review/[submitter_name]/[branch_name]
This option is useful if there are commits in the master that conflict with your changes.
Checkout the patchset. This checks out the patch set at the most recent patch number.
git fetch ssh://email@example.com:userid/onos refs/changes/18/18118/7 && git checkout FETCH_HEAD
git fetch origin master git rebase origin/master
Resolve conflicts. Resolve all conflicts related to the rebase
git status # if there are files in red, they need to be modified because there is a conflict vi myBrokenFile.txt
Add files to prepare for commit. If there are additional files you would like to add to this review, they can be added in this step
git add myBrokenFile.txt git add myOtherFile.txt
# If conflicts were resolved, you will need to --continue the rebase git rebase --continue # Finally amend your commit git commit --amend
Previous : Contributing to the ONOS Codebase
Next : Contributing to ONOS Documentation