system-config/doc/source/gerrit.rst

title

Gerrit

Gerrit

Gerrit is the code review system used by the OpenStack project. For a full description of how the system fits into the OpenStack workflow, see the GerritJenkinsGithub wiki article.

This section describes how Gerrit is configured for use in the OpenStack project and the tools used to manage that configuration.

At a Glance

Hosts

• http://review.openstack.org
• http://review-dev.openstack.org

Puppet

• modules/gerrit
• modules/openstack_project/manifests/review.pp
• modules/openstack_project/manifests/review_dev.pp

Configuration

• modules/openstack_project/templates/review.projects.yaml.erb

Projects

• http://code.google.com/p/gerrit/

Bugs

• http://bugs.launchpad.net/openstack-ci
• http://code.google.com/p/gerrit/issues/list

Resources

• Gerrit Documentation

Installation

Gerrit is installed and configured by Puppet, including specifying the exact Java WAR file that is used. See sysadmin for how Puppet is used to manage OpenStack infrastructure systems.

Gerrit Configuration

Most of Gerrit's configuration is in configuration files or Git repositories (and in our case, managed by Puppet), but a few items must be configured in the database. The following is a record of these changes:

Add "Approved" review type to gerrit:

mysql -u root -p
use reviewdb;
insert into approval_categories values ('Approved', 'A', 2, 'MaxNoBlock', 'N', 'APRV');
insert into approval_category_values values ('No score', 'APRV', 0);
insert into approval_category_values values ('Approved', 'APRV', 1);
update approval_category_values set name = "Looks good to me (core reviewer)" where name="Looks good to me, approved";

Expand "Verified" review type to -2/+2:

mysql -u root -p
use reviewdb;
update approval_category_values set value=2
  where value=1 and category_id='VRIF';
update approval_category_values set value=-2
  where value=-1 and category_id='VRIF';
insert into approval_category_values values
  ("Doesn't seem to work","VRIF",-1),
  ("Works for me","VRIF","1");

Reword the default messages that use the word Submit, as they imply that we're not happy with people for submitting the patch in the first place:

mysql -u root -p
use reviewdb;
update approval_category_values set name="Do not merge"
  where category_id='CRVW' and value=-2;
update approval_category_values
  set name="I would prefer that you didn't merge this"
  where category_id='CRVW' and value=-1;

Add information about the CLA:

insert into contributor_agreements values (
'Y', 'Y', 'Y', 'ICLA',
'OpenStack Individual Contributor License Agreement',
'static/cla.html', 2);

Groups

A number of system-wide groups are configured in Gerrit. These include Project Bootstrappers which grants all the permissions needed to set up a new project. Normally the OpenStack Project Creater account is the only member of this group, but members of the Administrators group may temporarily add themselves in order to correct problems with automatic project creation.

The External Testing Tools group is used to grant +/-1 Verified access to external testing tools.

GitHub Integration

Gerrit replicate to GitHub by pushing to a standard Git remote. The GitHub projects are configured to allow only the Gerrit user to push.

Pull requests can not be disabled for a project in Github, so instead we have a script that runs from cron to close any open pull requests with instructions to use Gerrit.

These are both handled automatically by jeepyb.

Auto Review Expiry

Puppet automatically installs a daily cron job called expire-old-reviews onto the gerrit servers. This script follows two rules:

1. If the review hasn't been touched in 2 weeks, mark as abandoned.
2. If there is a negative review and it hasn't been touched in 1 week, mark as abandoned.

If your review gets touched by either of these rules it is possible to unabandon a review on the gerrit web interface.

This process is managed by the jeepyb openstack-infra project.

Gerrit IRC Bot

Gerritbot consumes the Gerrit event stream and announces relevant events on IRC. gerritbot is an openstack-infra project and is also available on Pypi.

Launchpad Bug Integration

In addition to the hyperlinks provided by the regex in gerrit.config, we use a Gerrit hook to update Launchpad bugs when changes referencing them are applied. This is managed by the jeepyb openstack-infra project.

New Project Creation

Gerrit project creation is now managed through changes to the openstack-infra/config repository. jeepyb handles automatically creating any new projects defined in the configuration files.

Local Git Replica

Gerrit replicates all repos to a local directory so that Apache can serve the anonymous http requests out directly. This is automatically configured by jeepyb.

Access Controls

High level goals:

1. Anonymous users can read all projects.
2. All registered users can perform informational code review (+/-1) on any project.
3. Jenkins can perform verification (blocking or approving: +/-1).
4. All registered users can create changes.
5. The OpenStack Release Manager and Jenkins can tag releases (push annotated tags).
6. Members of $PROJECT-core group can perform full code review (blocking or approving: +/- 2), and submit changes to be merged.
7. Members of openstack-release (Release Manager and PTLs), and $PROJECT-milestone (PTL and release minded people) exclusively can perform full code review (blocking or approving: +/- 2), and submit changes to be merged on milestone-proposed branches.
8. Full code review (+/- 2) of API projects should be available to the -core group of the corresponding implementation project as well as to the OpenStack Documentation Coordinators.
9. Full code review of stable branches should be available to the -core group of the project as well as the openstack-stable-maint group.
10. Drivers (PTL and delegates) of client library projects should be able to add tags (which are automatically used to trigger releases).

To manage API project permissions collectively across projects, API projects are reparented to the "API-Projects" meta-project instead of "All-Projects". This causes them to inherit permissions from the API-Projects project (which, in turn, inherits from All-Projects).

These permissions try to achieve the high level goals:

All Projects (metaproject):
  refs/*
    read: anonymous
    push annotated tag: release managers, ci tools, project bootstrappers
    forge author identity: registered users
    forge committer identity: project bootstrappers
    push (w/ force push): project bootstrappers
    create reference: project bootstrappers, release managers
    push merge commit: project bootstrappers

  refs/for/refs/*
    push: registered users

  refs/heads/*
    label code review:
      -1/+1: registered users
      -2/+2: project bootstrappers
    label verified:
      -2/+2: ci tools
      -2/+2: project bootstrappers
      -1/+1: external tools
    label approved 0/+1: project bootstrappers
    submit: ci tools
    submit: project bootstrappers

  refs/heads/milestone-proposed
    label code review (exclusive):
      -2/+2 openstack-release
      -1/+1 registered users
    label approved (exclusive): 0/+1: openstack-release
    owner: openstack-release

  refs/heads/stable/*
    label code review (exclusive):
      -2/+2 opestack-stable-maint
      -1/+1 registered users
    label approved (exclusive): 0/+1: opestack-stable-maint

  refs/meta/*
    push: project bootstrappers

  refs/meta/config
    read: project bootstrappers
    read: project owners

API Projects (metaproject):
  refs/*
    owner: Administrators

  refs/heads/*
    label code review -2/+2: openstack-doc-core
    label approved 0/+1: openstack-doc-core

project foo:
  refs/*
    owner: Administrators
    create reference: foo-milestone  [client library only]
    push annotated tag: foo-milestone  [client library only]

  refs/heads/*
    label code review -2/+2: foo-core
    label approved 0/+1: foo-core

  refs/heads/milestone-proposed
    label code review -2/+2: foo-milestone
    label approved 0/+1: foo-milestone

Manual Administrative Tasks

The following sections describe tasks that individuals with root access may need to perform on rare occations.

Renaming a Project

Renaming a project is not automated and is disruptive to developers, so it should be avoided. Allow for an hour of downtime for the project in question, and about 10 minutes of downtime for all of Gerrit. All Gerrit changes, merged and open, will carry over, so in-progress changes do not need to be merged before the move.

To rename a project:

1. Prepare a change to the Puppet configuration which updates projects.yaml/ACLs and jenkins-job-builder for the new name.

2. Stop puppet on review.openstack.org to prevent your interim configuration changes from being reset by the project management routines:

   sudo puppetd --disable

3. Make the project inacessible by editing the Access pane. Add a "read" ACL for "Administrators", and mark it "exclusive". Be sure to save changes.

4. Update the database on review.openstack.org:

   sudo mysql --defaults-file=/etc/mysql/debian.cnf reviewdb
   
   update account_project_watches
   set project_name = "openstack/NEW"
   where project_name = "openstack/OLD";
   
   update changes
   set dest_project_name = "openstack/NEW"
   where dest_project_name = "openstack/OLD";

5. Take Jenkins offline through its WebUI.

6. Stop Gerrit on review.openstack.org and move both the Git repository and the mirror:

   sudo invoke-rc.d gerrit stop
   sudo mv ~gerrit2/review_site/git/openstack/{OLD,NEW}.git
   sudo mv /var/lib/git/openstack/{OLD,NEW}.git
   sudo invoke-rc.d gerrit start

7. Bring Jenkins online through its WebUI.

8. Merge the prepared Puppet configuration change, removing the original Jenkins jobs via the Jenkins WebUI later if needed.

9. Start puppet again on review.openstack.org:

   sudo puppetd --enable

10. Rename the project in GitHub or, if this is a move to a new org, let the project management run create it for you and then remove the original later (assuming you have sufficient permissions).

11. If this is an org move and the project name itself is not changing, gate jobs may fail due to outdated remote URLs. Clear the workspaces on persistent Jenkins slaves to mitigate this:

    ssh -t $h.slave.openstack.org 'sudo rm -rf ~jenkins/workspace/*PROJECT*'

12. Again, if this is an org move rather than a rename and the GitHub project has been created but is empty, trigger replication to populate it:

    ssh -p 29418 review.openstack.org gerrit replicate --all

13. Wait for puppet changes to be applied so that the earlier restrictive ACL will be reset for you (ending the outage for this project).

14. Submit a change that updates .gitreview with the new location of the project.

Developers will either need to re-clone a new copy of the repository, or manually update their remotes with something like:

git remote set-url origin https://github.com/$ORG/$PROJECT.git

Deleting a User from Gerrit

This isn't normally necessary, but if you find that you need to completely delete an account from Gerrit, here's how:

delete from account_agreements where account_id=NNNN;
delete from account_diff_preferences where id=NNNN;
delete from account_external_ids where account_id=NNNN;
delete from account_group_members where account_id=NNNN;
delete from account_group_members_audit where account_id=NNNN;
delete from account_patch_reviews where account_id=NNNN;
delete from account_project_watches where account_id=NNNN;
delete from account_ssh_keys where account_id=NNNN;
delete from accounts where account_id=NNNN;

ssh review.openstack.org -p29418 gerrit flush-caches --all