Documentation/internals/release-process.rst

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  16       =======  Heading 0 (reserved for the title in a document)
  17       -------  Heading 1
  18       ~~~~~~~  Heading 2
  19       +++++++  Heading 3
  20       '''''''  Heading 4
  21
  22       Avoid deeper levels because they do not render well.
  23
  24 ============================
  25 Open vSwitch Release Process
  26 ============================
  27
  28 This document describes the process ordinarily used for Open vSwitch
  29 development and release.  Exceptions are sometimes necessary, so all of the
  30 statements here should be taken as subject to change through rough consensus of
  31 Open vSwitch contributors, obtained through public discussion on, e.g., ovs-dev
  32 or the #openvswitch IRC channel.
  33
  34 Release Strategy
  35 ----------------
  36
  37 Open vSwitch feature development takes place on the "master" branch.
  38 Ordinarily, new features are rebased against master and applied directly.  For
  39 features that take significant development, sometimes it is more appropriate to
  40 merge a separate branch into master; please discuss this on ovs-dev in advance.
  41
  42 The process of making a release has the following stages.  See `Release
  43 Scheduling`_ for the timing of each stage:
  44
  45 1. "Soft freeze" of the master branch.
  46
  47    During the freeze, we ask committers to refrain from applying patches that
  48    add new features unless those patches were already being publicly discussed
  49    and reviewed before the freeze began.  Bug fixes are welcome at any time.
  50    Please propose and discuss exceptions on ovs-dev.
  51
  52 2. Fork a release branch from master, named for the expected release number,
  53    e.g. "branch-2.3" for the branch that will yield Open vSwitch 2.3.x.
  54
  55    Release branches are intended for testing and stabilization.  At this stage
  56    and in later stages, they should receive only bug fixes, not new features.
  57    Bug fixes applied to release branches should be backports of corresponding
  58    bug fixes to the master branch, except for bugs present only on release
  59    branches (which are rare in practice).
  60
  61    At this stage, sometimes there can be exceptions to the rule that a release
  62    branch receives only bug fixes.  Like bug fixes, new features on release
  63    branches should be backports of the corresponding commits on the master
  64    branch.  Features to be added to release branches should be limited in scope
  65    and risk and discussed on ovs-dev before creating the branch.
  66
  67 3. When committers come to rough consensus that the release is ready, they
  68    release the .0 release on its branch, e.g. 2.3.0 for branch-2.3.  To make
  69    the actual release, a committer pushes a signed tag named, e.g. v2.3.0, to
  70    the Open vSwitch repository, makes a release tarball available on
  71    openvswitch.org, and posts a release announcement to ovs-announce.
  72
  73 4. As bug fixes accumulate, or after important bugs or vulnerabilities are
  74    fixed, committers may make additional releases from a branch: 2.3.1, 2.3.2,
  75    and so on.  The process is the same for these additional release as for a .0
  76    release.
  77
  78 At most two release branches are formally maintained at any given time: the
  79 latest release and the latest release designed as LTS.  An LTS release is one
  80 that the OVS project has designated as being maintained for a longer period of
  81 time.  Currently, an LTS release is maintained until the next LTS is chosen.
  82 There is not currently a strict guideline on how often a new LTS release is
  83 chosen, but so far it has been about every 2 years.  That could change based on
  84 the current state of OVS development.  For example, we do not want to designate
  85 a new release as LTS that includes disruptive internal changes, as that may
  86 make it harder to support for a longer period of time.  Discussion about
  87 choosing the next LTS release occurs on the OVS development mailing list.
  88
  89 Release Numbering
  90 -----------------
  91
  92 The version number on master should normally end in .90.  This indicates that
  93 the Open vSwitch version is "almost" the next version to branch.
  94
  95 Forking master into branch-x.y requires two commits to master.  The first is
  96 titled "Prepare for x.y.0" and increments the version number to x.y.  This is
  97 the initial commit on branch-x.y.  The second is titled "Prepare for post-x.y.0
  98 (x.y.90)" and increments the version number to x.y.90.
  99
 100 The version number on a release branch is x.y.z, where z is initially 0.
 101 Making a release requires two commits.  The first is titled *Set release dates
 102 for x.y.z.* and updates NEWS and debian/changelog to specify the release date
 103 of the new release.  This commit is the one made into a tarball and tagged.
 104 The second is titled *Prepare for x.y.(z+1).* and increments the version number
 105 and adds a blank item to NEWS with an unspecified date.
 106
 107 Release Scheduling
 108 ------------------
 109
 110 Open vSwitch makes releases at the following six-month cadence.  All dates are
 111 approximate:
 112
 113 +---------------+----------------+--------------------------------------+
 114 | Time (months) | Dates          | Stage                                |
 115 +---------------+----------------+--------------------------------------+
 116 | T             | Mar 1, Sep 1   | Begin x.y release cycle              |
 117 +---------------+----------------+--------------------------------------+
 118 | T + 4         | Jul 1, Jan 1   | "Soft freeze" master for x.y release |
 119 +---------------+----------------+--------------------------------------+
 120 | T + 4.5       | Jul 15, Jan 15 | Fork branch-x.y from master          |
 121 +---------------+----------------+--------------------------------------+
 122 | T + 5.5       | Aug 15, Feb 15 | Release version x.y.0                |
 123 +---------------+----------------+--------------------------------------+
 124
 125 How to Branch
 126 -------------
 127
 128 To branch "master" for the eventual release of OVS version x.y.0,
 129 prepare two patches against master:
 130
 131 1. "Prepare for x.y.0." following the model of commit 836d1973c56e
 132    ("Prepare for 2.11.0.").
 133
 134 2. "Prepare for post-x.y.0 (x.y.90)." following the model of commit
 135    fe2870c574db ("Prepare for post-2.11.0 (2.11.90).")
 136
 137 Post both patches to ovs-dev.  Get them reviewed in the usual way.
 138
 139 Apply both patches to master, and create branch-x.y by pushing only
 140 the first patch.  The following command illustrates how to do both of
 141 these at once assuming the local repository HEAD points to the
 142 "Prepare for post-x.y.0" commit:
 143
 144         git push origin HEAD:master HEAD^:refs/heads/branch-x.y
 145
 146 Branching should be announced on ovs-dev.
 147
 148 How to Release
 149 --------------
 150
 151 Follow these steps to release version x.y.z of OVS from branch-x.y.
 152
 153 1. Prepare two patches against branch-x.y:
 154
 155    a. "Set release date for x.y.z".  For z = 0, follow the model of
 156       commit d11f4cbbfe05 ("Set release date for 2.12.0."); for z > 0,
 157       follow the model of commit 53d5c18118b0 ("Set release date for
 158       2.11.3.").
 159
 160    b. "Prepare for x.y.(z+1)." following the model of commit
 161       db02dd23e48a ("Prepare for 2.11.1.").
 162
 163 3. Post the patches to ovs-dev.  Get them reviewed in the usual way.
 164
 165 4. Apply the patches to branch-x.y.
 166
 167 5. If z = 0, apply the first patch (only) to master.
 168
 169 6. Sign a tag vx.y.z "Open vSwitch version x.y.z" and push it to the
 170    repo.
 171
 172 7. Update http://www.openvswitch.org/download/.  See commit
 173    31eaa72cafac ("Add 2.12.0 and older release announcements.") in the
 174    website repo (https://github.com/openvswitch/openvswitch.github.io)
 175    for an example.
 176
 177 8. Consider updating the Wikipedia page for Open vSwitch at
 178    https://en.wikipedia.org/wiki/Open_vSwitch
 179
 180 9. Tweet.
 181
 182 Contact
 183 -------
 184
 185 Use dev@openvswitch.org to discuss the Open vSwitch development and release
 186 process.