Release Process
Release Process Overview
Special thanks to Michael Stone for creating most of the existing pages and spending time getting me up to speed on how its done now.
Also to Charles Merriam for helping show how good it can get
http://lists.laptop.org/pipermail/devel/2008-April/012318.html
This is a first draft. Please send comments, questions and suggestions to greg at laptop.org
Gregorio 08:46, 27 June 2008 (UTC) (UTC)
The goals of this process are:
- Ensure high quality releases which meet the needs of users in a timely fashion.
- Maximize the participation, productivity and enthusiasm of the open source community.
- Create a predictable process which helps users and developers plan for the future.
Time-based Releases
A Release consists of set of builds, documentation, an approved ECO, a completed checklist and support as defined below.
For example, see 8.1.0 Release Notes, the most recent Release as of this writing --Greg 14:09, 25 June 2008 (UTC) is 8.1.0.:
Each release will have a page linked from the Releases page
Time-based means that we have a target release day well in advance. It also means that we have a plan to begin the final test on a specific day. It does not mean that the release is guaranteed to be complete on the target release day. Features and non-critical bug fixes will be deferred to make the release day. However, a minimum standard of quality as defined by the Release Team must be met before the release is final. The release will be delayed until that minimum quality standard is met.
The definition of a minimum quality standard must be worked out and refined over time in consultation with customers and developers. It should be a priority of development and test teams to define that in advance and codify it as effectively as possible.
The choice of time based releases is motivated by its success in a growing number of open source projects. For examples, see the Fedora, Ubuntu and Gnome projects.
Major Releases
A Major Release includes significant new features. There will be two Major releases twice a year (one in the first half of the calendar year and one in the second half of the calendar year).
Each Major Release will be supported for a period of 1 year from the time the Release Process Checklist is complete. The date in the "Release team final sign off" field defines the start of the 1 year support time frame.
Support means that a Minor Release with bug fixes will be built at OLPC's discretion based on discussion with customers and other stakeholders.
Example names of Major Releases are 8.1.0, 8.2.0, 9.1.0, 9.2.0
Minor Releases
Minor releases will focus on bug fixes and will come out as often as negotiated by customers and OLPC. Minor releases may include new features if the release manager and primary customers agree they are well tested and documented. Minor releases must be fully backward compatible with the major release that they are based on. That is, activities and APIs must continue to work as before.
An example reason for generating a Minor release would be to add support for an additional languages.
All the bug fixes and changes in a minor release will be tracked and recorded in a software ECO and included in the release notes. See the full minor release process definition at: http://wiki.laptop.org/go/Unscheduled_software_release_process
Example names of Minor Releases names are 8.1.1, 8.1.2, 8.2.1, 8.2.2
Release and Build Naming Conventions
Release Names
The release names are of the form "Y.H.NN"
- Y = target calendar year
- H = major release number representing calendar year half (1 or 2)
- NN = minor release number
Example Names
- 8.1.1 First Minor Release rebuild based on the first Major Release in CY08
- 8.2.0 Second Major Release in CY08
Recall that releases consist of a family of builds derived from a reference OS, along with "polish" like documentation, signatures, &etc.
The build family consists of a reference OS named:
official-nnn
which lives on http://download.laptop.org/xo-1/os/official/. The word "official" means that it is a final Major or Minor Release build (link to doc, etc.). The "nnn" is an integer uniquely identifying the source code. An example is official-703.
Derivative builds may be created locally by anyone. However, cryptographic signatures are required to enable "cheap" mass installation of the derivatives. No signatures are required if you are willing to use OLPC-supported USB customization technology or if you request developer keys for all your machines.
Derivative builds are named as follows:
variant-nnn-n
The "variant" field is typically a short string identifying a deployment or language group such as "peru" or "en". When the build name does not start with "official" it means that either:
- the reference operating system was customized to produce a derivative build, in which case the name will be as above, or
- a fork has taken place.
For example,
peru-703-6 is the customized build created for Peru based on the source code identified by 703.
and
en-708-1 is the English language customization of release candidate build 708. This is not an official Release unless and until official-708 is released and it is documented on the release page.
Types of Builds
Each build consists of a core OS. At the discretion of the Release Team, the build may or may not contain activities.
One way of classifying a build is to identify its readiness to be a Release.
There are four types of builds in that classification:
- Released images - (a.k.a. "stable") with release notes and ECO. This is a signed image which does not need a developer key to install on an XO. (e.g. official-703; the OS component of the 8.1.0 Release)
- Release candidates - (a.k.a. "testing") release candidates which are in change control and may become official releases if it passes the test cycle. (e.g. candidate-708; tentatively the OS component of the 8.1.1 Release )
- Development images - (a.k.a. "unstable") - the latest image with the latest code but it is also likely to contain significant bugs. (e.g. joyride-2072)
- Experimental images - images which are not expected to work and which are used for creating major new functionality; typically a part of "topic branches". (e.g. faster-2072)
More details on available builds and how to get them are here.
See also http://wiki.laptop.org/go/Build_system.
For a developer wanting to contribute new code we recommend the following steps:
- Decide whether you want to hack on activities, releases, bugs, or experimental features.
- Choose the corresponding build type: released images, candidates, development images, or your own topic branch.
- Send an e-mail to devel@lists.laptop.org and/or sugar@lists.laptop.org explaining your work and gathering feedback.
- Implement a basic first pass which compiles and shows the main idea. Post a link to its source to the same lists, preferably in a patch-like format.
- Revise as needed based on feedback.
- If possible, get the changes included in an upstream repository or, as appropriate, ask the list for details on how to package it locally for the XO.
Release candidates are the builds that may replace the current 'stable' designation. Release candidates are created during the execution of software engineering change orders. See details of ECO creation steps in the Release Process page and An Example ECO for 8.1.1
Note: each successful build generates products that can be installed on some system. For example, release builds contain disk images suitable for flashing to NAND, for consumption by OLPC update, for inspection on other systems, and for simulation in QEMU. Traditionally, important builds are announced on devel@lists.laptop.org.
Release Schedules
Getting a stable build out can be hard. A branch grows in stability over time and stability of the release and field testing the final release candidate takes time.
The steps to creating a release schedule are as follows.
Step 1 - New Major Release is named.
Step 2 - Release objectives and lead customer identified. Target features listed and target date down to the month is chosen.
The module maintainer, with his peers and the community comes up with
a set of features for the release. Product Management participates in the discussion
and informs it based of customers feedback. Product Management and the
relevant module maintainers are responsible to build consensus. The
module maintainers are responsible to ensure that the code going in
git repositories is consistent with that consensus.
Step 3 - Schedule is posted.
"Change Control (CC) of X" means that you need to convince the maintainer of X to merge your change instead of pushing it yourself. What we call Change Control, many projects call "Feature Freeze".
Milestones
- 45 days before target date CC of Features No new features added after this.
- 30 days before target date CC of the Release Only approved bugs allowed in after this
- 15 days before target date CC of the Release Show Stoppers only Only critical must have bugs allowed after this
- <15 days before target date Final Test Get consensus from test community, QA, and engineering then finish the Release Process Checklist.
- Release day. Announcement Day Once Release checklist is complete, Kim sends announcement e-mail approving release for production.
Defintions
- CC of Features
After this date only new features which are approved by module maintainers and Product Management are allowed in. Bug fixes can still be added without approval for another 15 days. All strings must be final by this time. All user interface changes must be final by this time.
- CC of the Release
All translation packages must be final by this time.
No string changes after this time.
On or before this date Module maintainers propose a set of bug fixes to get into the stable
branch. They usually do so by releasing a new version of their module
and informing the release team about the changes it contains and the
steps necessary to test those. The release team will make sure that
the relevant QA is executed and either approve the changes or ask for
fixes/improvements. As soon as the changes are approved they are added
to the stable build. After this date no changes are allowed in to the code without the approval of the module maintainer and the Release Triage team.
- CC of the Release Show Stoppers
As of this date every single change to the source code needs to be approved by the Release Team before it happens.
- Final Test
This is when the count down to release starts. The release is not final until the Release Team signs off and the Release Process Checklist is complete.
- Announcement Day
This is the target release day but it is not the actual release day until the Final Test milestone is passed.
Release Steps
Minor Releases follow the process outline here:
http://wiki.laptop.org/go/Unscheduled_software_release_process
In particular a Release must complete the checklist:
http://wiki.laptop.org/go/USR_Checklist
A Major Release follows the process documented here:
http://wiki.laptop.org/go/Plan_of_Record-2008/Draft_3#RM:_Release_Mechanisms
Release Goals and Request Prioritization
TBD.
Existing thinking on the current plan is here
http://wiki.laptop.org/go/Plan_of_Record-2008/Draft_3
Summary and Open Items
The OLPC Build Process is getting cleaner, faster, and more reliable. The new time-based release cycle provides the regularity needed by developers and users.
Open items needing definition and additional work
- Finalize Major Release process details and create page for it
- Update and post a new picture of the release process and release trains
- Create a schedule for 8.1.1 and 8.2.0
- List the software components, maintainers and modules in a release.
- Define feature and bug prioritization process
- Define release quality metrics and include test details and milestones
- Create governance and community best practices guidelines
- Gather community buy in and get consensus
- Finalize release and triage teams
- Review and finalize Status page
- Put the process in to practice, revise and improve