Gerrit Integration

Gerrit Integration

What is Gerrit?

Gerrit is an open-source, web-based code review system developed by Google. It’s used by major projects like Android, Chromium, and Go. Unlike GitHub’s Pull Requests, Gerrit uses Change Lists (CLs) pushed to special refs/for/* references. See the Glossary for more details.

Copybara integrates with Gerrit for organizations using Gerrit for code review.

Origins

git.gerrit_origin

Read from a Gerrit repository:

origin = git.gerrit_origin(
    url = "https://gerrit.example.com/repo",
    ref = "refs/heads/main",
)

Parameters

Parameter	Description
url	Gerrit repository URL
ref	Git reference to sync
change_number_url	URL pattern for changes

Destinations

git.gerrit_destination

Create Gerrit change lists (CLs):

destination = git.gerrit_destination(
    url = "https://gerrit.example.com/repo",
    fetch = "main",
    push_to_refs_for = "main",
)

Parameters

Parameter	Description
url	Gerrit repository URL
fetch	Branch to fetch from
push_to_refs_for	Target branch for the CL
submit	Auto-submit if approved
notify	Notification level
topic	CL topic
change_id_policy	How to handle Change-Id

Examples

# Basic CL creation
destination = git.gerrit_destination(
    url = "https://gerrit.example.com/repo",
    fetch = "main",
    push_to_refs_for = "main",
)

# With topic
destination = git.gerrit_destination(
    url = "https://gerrit.example.com/repo",
    fetch = "main",
    push_to_refs_for = "main",
    topic = "copybara-sync",
)

# With notification control
destination = git.gerrit_destination(
    url = "https://gerrit.example.com/repo",
    fetch = "main",
    push_to_refs_for = "main",
    notify = "OWNER",  # Only notify owner
)

API Integration

git.gerrit_api

Interact with Gerrit API in feedback workflows:

destination = git.gerrit_api(
    url = "https://gerrit.example.com",
)

Actions

def _my_action(ctx):
    # Post a review
    ctx.destination.post_review(
        change_id = ctx.ref,
        review_input = git.review_input(
            labels = {"Code-Review": 1},
            message = "Automated review",
        ),
    )
    return ctx.success()

Change-Id Handling

Gerrit uses Change-Id to track changes. Copybara handles this automatically:

destination = git.gerrit_destination(
    url = "...",
    change_id_policy = "REQUIRE",  # Fail if no Change-Id
)

Options:

• "REQUIRE" - Fail if Change-Id is missing
• "FAIL_IF_PRESENT" - Fail if Change-Id exists
• "REUSE" - Reuse existing Change-Id
• "REPLACE" - Replace with new Change-Id

Common Patterns

Import External to Gerrit

core.workflow(
    name = "import",
    origin = git.github_pr_origin(
        url = "https://github.com/org/public-repo",
        branch = "main",
    ),
    destination = git.gerrit_destination(
        url = "https://gerrit.internal/repo",
        fetch = "main",
        push_to_refs_for = "main",
    ),
    mode = "CHANGE_REQUEST_FROM_SOT",
    ...
)

Export Internal to External

core.workflow(
    name = "export",
    origin = git.gerrit_origin(
        url = "https://gerrit.internal/repo",
        ref = "refs/heads/main",
    ),
    destination = git.github_destination(
        url = "https://github.com/org/public-repo",
        push = "main",
    ),
    mode = "SQUASH",
    ...
)

Authentication

Gerrit typically uses:

• HTTP credentials (username + password/token)
• SSH keys

# HTTP credentials
git config --global credential.helper store
echo "https://user:token@gerrit.example.com" > ~/.git-credentials

# SSH
ssh-add ~/.ssh/id_ed25519

Note

For Gerrit HTTP access, you may need to generate an HTTP password in Gerrit settings.

Next Steps

• GitHub integration
• Workflow modes