This document presents some best practices to help you use Gerrit more effectively. The intent is to show how content can be submitted easily. Use the recommended practices to reduce your troubleshooting time and improve participation in the community.
Gerrit follows the Git commit message format. Ensure the headers are at the bottom and don't contain blank lines between one another. The following example shows the format and content expected in a commit message:
Brief (no more than 50 chars) one line description.
Elaborate summary of the changes made referencing why (motivation), what was changed and how it was tested. Note also any changes to documentation made to remain consistent with the code changes, wrapping text at 72 chars/line.
Bug-AGL: SPEC-<JIRA-ID> Change-Id: LONGHEXHASH Signed-off-by: Your Name your.email\@example.org
The Gerrit server provides a precommit hook to autogenerate the Change-Id which is one time use.
Recommended reading: How to Write a Git Commit Message.
Avoid Pushing Untested Work to a Gerrit Server
To avoid pushing untested work to Gerrit.
Check your work at least three times before pushing your change to Gerrit. Be mindful of what information you are publishing.
Keeping Track of Changes
Set Gerrit to send you emails:
Gerrit will add you to the email distribution list for a change if a developer adds you as a reviewer, or if you comment on a specific Patch Set.
Opening a change in Gerrit's review interface is a quick way to follow that change.
Watch projects in the Gerrit projects section at
Gerrit, select at least New Changes, New Patch Sets, All Comments and Submitted Changes.
Always track the projects you are working on; also see the feedback/comments mailing list to learn and help others ramp up.
Topic branches are temporary branches that you push to commit a set of logically-grouped dependent commits:
To push changes from
REMOTE/needlefish tree to Gerrit for being reviewed as a
topic in TopicName use the following command as an example:
$ git push REMOTE HEAD:refs/for/needlefish/TopicName
The topic will show up in the review
UI and in the
Open Changes List.
Topic branches will disappear from the needlefish tree when its content is merged.
Finding Available Topics
$ ssh -p 29418 <LFID>@gerrit.automotivelinux.org gerrit query \ status:open branch:needlefish| grep topic: | sort -u
- gerrit.automotivelinux.org is the current URL where the project is hosted.
- status : Indicates the topic's current status: open , merged, abandoned, draft, merge conflict.
- project : Refers to the current name of the project, in this case fabric.
- branch : The topic is searched at this branch.
- topic : The name of an specific topic, leave it blank to include them all.
- sort : Sorts the found topics, in this case by update (-u).
Downloading or Checking Out a Change
In the review UI, on the top right corner, the Download link provides a list of commands and hyperlinks to checkout or download diffs or files.
We recommend the use of the git review plugin. The steps to install git review are beyond the scope of this document. Refer to the git review documentation for the installation process.
To check out a specific change using Git, the following command usually works:
$ git review -d CHANGEID
If you don't have Git-review installed, the following commands will do the same thing:
$ git fetch REMOTE refs/changes/NN/CHANGEIDNN/VERSION \ && git checkout FETCH_HEAD
For example, for the 4th version of change 2464, NN is the first two digits (24):
$ git fetch REMOTE refs/changes/24/2464/4 \ && git checkout FETCH_HEAD
Using Sandbox Branches
You can create your own branches to develop features. The branches are pushed to
These commands ensure the branch is created in Gerrit's server.
$ git checkout -b sandbox/USERNAME/BRANCHNAME $ git push --set-upstream REMOTE HEAD:refs/heads/sandbox/USERNAME/BRANCHNAME
Usually, the process to create content is:
- develop the code,
- break the information into small commits,
- submit changes,
- apply feedback,
The next command pushes forcibly without review:
$ git push REMOTE sandbox/USERNAME/BRANCHNAME
You can also push forcibly with review:
$ git push REMOTE HEAD:ref/for/sandbox/USERNAME/BRANCHNAME
Updating the Version of a Change
During the review process, you might be asked to update your change. It is possible to submit multiple versions of the same change. Each version of the change is called a patch set.
Always maintain the Change-Id that was assigned. For example, there is a list of commits, c0...c7, which were submitted as a topic branch:
$ git log REMOTE/needlefish..needlefish c0 ... c7 $ git push REMOTE HEAD:refs/for/needlefish/SOMETOPIC
After you get reviewers' feedback, there are changes in c3 and c4 that must be fixed. If the fix requires rebasing, rebasing changes the commit Ids, see the rebasing section for more information. However, you must keep the same Change-Id and push the changes again:
$ git push REMOTE HEAD:refs/for/needlefish/SOMETOPIC
This new push creates a patches revision, your local history is then cleared.
However you can still access the history of your changes in Gerrit on the
review UI section, for each change.
It is also permitted to add more commits when pushing new versions.
Rebasing is usually the last step before pushing changes to Gerrit; this allows you to make the necessary Change-Ids. The Change-Ids must be kept the same.
- squash: mixes two or more commits into a single one.
- reword: changes the commit message.
- edit: changes the commit content.
- reorder: allows you to interchange the order of the commits.
- rebase: stacks the commits on top of the needlefish.
Rebasing During a Pull
Before pushing a rebase to your needlefish, ensure that the history has a consecutive order.
For example, your
REMOTE/needlefish has the list of commits from a0 to
a4; Then, your changes c0...c7 are on top of a4; thus:
$ git log --oneline REMOTE/needlefish..needlefish a0 a1 a2 a3 a4 c0 c1 ... c7
REMOTE/needlefish receives commits a5, a6 and a7. Pull with a
rebase as follows:
$ git pull --rebase REMOTE needlefish
This pulls a5-a7 and re-apply c0-c7 on top of them:
$ git log --oneline REMOTE/needlefish..needlefish a0 ... a7 c0 c1 ... c7
Getting Better Logs from Git
Use these commands to change the configuration of Git in order to produce better logs:
$ git config log.abbrevCommit true
The command above sets the log to abbreviate the commits' hash.
$ git config log.abbrev 5
The command above sets the abbreviation length to the last 5 characters of the hash.
$ git config format.pretty oneline
The command above avoids the insertion of an unnecessary line before the Author line.