How to submit code to gerrit for review

Prerequisites

  1. Generate an ssh key and add it to Gerrit.

First, run ssh-keygen in your terminal, and accept all of the default parameters by hitting enter. Then go to Gerrit, click on your name in the top right corner and click settings. Choose SSH Public Keys on the side bar and click Add Key. Copy paste the contents of ~/.ssh/id_rsa.pub into the box and hit okay.

  1. Add the gerrit change-id git hook to your local repository

If you used the clone with commit-msg hook command when you first cloned the code, you can skip this step. If you did not, run the following commands from the 971-Robot-Code directory, replacing <username> with your gerrit username.

scp -p -P 29418 <username>@software.frc971.org:hooks/commit-msg .git/hooks/

Submitting code for review

  1. Choose what changes you want to commit
  • You can see what files you've changed using git status
  • You can use git diff to see exactly what you changed. Note that this will not show you new files that you've created locally.

  1. Once you know what you want to commit, use git add <file> to "stage" them for the commit. You should only add the changes that you want, so if your files contain things you don't want to commit, you'll have to cut out the stuff you don't want before using git add.

  2. After you've used git add to add all the changes you want to commit, run git commit -s and write an informative commit message in the editor that pops up. Save and quit in the editor that opens to actually commit your changes. If you change your mind about committing, you can quit without saving to cancel the commit.

    • You can use git commit -v to see what changes git thinks you want to commit in the commit message editor.
    • If your commit message is short, you can use git commit -m "<message>" to specify it on the command line.
    • The additional -s adds a signed-off-by trailer to put your name on the review for open sourcing.

  3. Send your changes to Gerrit by running git push origin HEAD:refs/for/main.

    • A link to the Gerrit web interface will be printed for you to copy paste into your browser.

  4. Add reviewers to your change request so that your code can be reviewed and approved after feedback.

Editing your submitted change

Gerrit allows you to edit your change and resubmit it.

  1. Make sure that the commit you want to edit is the latest in your commit history by running git show and making sure that the commit is the one you want to edit.

  2. Make the changes you want to make.

  3. Add the changes using git add <file1> <file2> ....

  4. Add the changes you made to the previous commit by running git commit --amend -s. This will allow you to edit the previous commit message. MAKE SURE YOU DON'T EDIT THE GERRIT Change-Id. This is what Gerrit uses to know that you're updating an existing change instead of pushing a new one.

  5. Send the updated change to Gerrit with git push origin HEAD:refs/for/main.

Troubleshooting

  • If your commit is missing a Change-Id, you'll get a reasonably understandable error that looks like the following:
Counting objects: 5, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (5/5), done.
Writing objects: 100% (5/5), 2.83 KiB | 0 bytes/s, done.
Total 5 (delta 1), reused 0 (delta 0)
remote: Resolving deltas: 100% (1/1)
remote: Processing changes: refs: 1, done
remote: ERROR: [bf965b4] missing Change-Id in commit message footer
remote:
remote: Hint: To automatically insert Change-Id, install the hook:
remote:   gitdir=$(git rev-parse --git-dir); scp -p -P 29418 adrian@software.frc971.org:hooks/commit-msg ${gitdir}/hooks/
remote: And then amend the commit:
remote:   git commit --amend
remote:

If you see this, run the commands that they suggest in the error message and push it again