Fuchsia's Gerrit code review site supports an automatic change submission feature. Any change that is opted in will automatically be submitted after being approved and passing presubmit checks.
Note: Auto-submit is a Fuchsia-specific feature and its use and behavior do not generalize to other Gerrit hosts, such as Chromium and Android, that use Commit Queue or have their own auto-submit functionality.
When adding reviewers in the Gerrit UI using the REPLY dialog, select the +1 for the Fuchsia-Auto-Submit label.
After your change meets all the submit requirements (generally a Code-Review +2 vote and owner approval of all affected files), the auto-submit bot will apply the Commit-Queue +2 label. Once all presubmit checks pass, your change will automatically be submitted.
If you want your change to land as soon as possible after approval, it‘s recommended that you set Commit-Queue +1 before (or at the same time as) sending your change for review. When auto-submit applies the Commit-Queue +2 label, it will skip rerunning any checks that have already passed within the last 24 hours, so submission often doesn’t need to wait for checks to rerun.
Auto-submit will typically apply Commit-Queue +2 to your change within 30 seconds of it being approved, but it may take up to 2 minutes.
Auto-submit is implemented as a job that polls Gerrit for submittable changes every 30 seconds, but there may be occasional delays when the job restarts.
If the author of a change has opted into auto-submit, a Fuchsia-Auto-Submit +1 tile will appear under Trigger Votes in the left column of the Gerrit UI.
Auto-submit retries presubmit four times, using exponential backoff. It intentionally assumes that any failures are false rejections due to latent flakiness or transient breakages at HEAD. This makes auto-submit resilient to false rejections, at the cost of occasionally retrying presubmit on CLs that are legitimately broken and have no hope of passing presubmit checks.
If auto-submit's presubmit attempts fail four times in a row, auto-submit will stop retrying and remove the Fuchsia-Auto-Submit +1 label from the CL. To continue retrying, you can manually add Fuchsia-Auto-Submit +1 back to the CL and it will retry presubmit four more times.
If incorrectly retrying is a concern, make sure a presubmit dry run passes before sending your change for review, or don‘t use auto-submit. Alternatively, use the Multiply directive if you’re concerned about flakiness.
If you leave unresolved comments at the time you grant Code-Review +2, the auto-submit bot will not submit the change until all comments are resolved.
FYI builders added through the Choose Tryjobs menu do not block auto-submit. Exercise caution with FYI builders.
