[Xen-devel] A document for Xen release management, v2

[Wei Liu <wei.liu2@xxxxxxxxxx>]

Hi all

This is v2 of this document.

Lars, please insert your section as you see fit.

Wei.

---8<---
% Xen Release Management
% Wei Liu <<wei.liu2@xxxxxxxxxx>>
% Revision 1

# Motivation

Over the years we have had different people signing up as the Release Manager
of Xen. It would be rather wasteful if every new Release Manager has to go over
everything and tripped over by the same mistakes again and again.

This file intends to document the process of managing a Xen release. It is
mainly written for Release Manager, but other roles (contributors,
maintainers and committers) are also encouraged to read this document, so
that they can have an idea what to expect from the Release Manager.

# Xen release cycle

The Xen hypervisor project now releases twice a year, at the beginning of
June and the beginning of December. The actual release date depends on a lot
of factors. 

We can roughly divide one release into two periods. The development period
and the freeze period. The former is 4 months long and the latter is about 2
months long.

During development period, contributors submit patches to be reviewed and
committed into xen.git. All feature patches must be committed before a date,
which is normally called the "cut-off date", after which the freeze period
starts. There will be a date before which all patches that wish to be merged
for the release should be posted -- it is normally called the "last posting
date" and it is normally two weeks before the "cut-off date".

During freeze period, the tree is closed for new features. Only bug fixes are
accepted. This period can be shorter or longer than 2 months. If it ends up
longer than 2 months, it eats into the next development period.

Here is a conjured up example (use ````cal 2017```` to get an idea):

* Development period: 2017 June 11 - 2017 September 29
    * the "cut-off date" is 2017 September 29
    * the "last posting date" is 2017 September 15
* Freeze period: 2017 October 2 - 2017 December 7
    * the anticipated release date is 2017 December 7

# The different roles in a Xen release

## Release Manager

A trusted developer in the community that owns the release process. The major
goal of the Release Manager is to make sure a Xen release has high quality
and doesn't slip too much.

The Release Manager will not see much workload during development period, but
expects to see increasing workload during the freeze period until the final
release. He or she is expected to keep track of issues, arrange RCs,
negotiate with relevant stakeholders, balance the need from various parties
and make difficult decisions when necessary.

The Release Manager essentially owns xen-unstable branch during the freeze
period. The committers will act on the wishes of the Release Manager during
that time.

## Maintainers

A group of trusted developers who are responsible for certain components in
xen.git. They are expected to respond to patches / questions with regard to
their components in a timely manner, especially during the freeze period.

## Committers

A group of trusted maintainers who can commit to xen.git. During the
development window they normally push things as they see fit. During the
freeze period they transfer xen-unstable branch ownership and act on the
wishes of the Release Manager. That normally means they need to have an
Release Ack in order to push a patch.

## Contributors

Contributors are also expected to respond quickly to any issues regarding the
code they submitted during development period. Failing that, the Release
Manager might decide to revert the changes, declare feature unsupported or
take any action he / she deems appropriate.

## The Security Team

The Security Team operates independently. The visibility might be rather
limited due to the sensitive nature of security work. The best action the
Release Manager can take is to set aside some time for potential security
issues to be fixed.

## The Release Technician

The Release Technician is the person who tags various trees, prepares tarball
etc. He or she acts on the wishes of the Release Manager. Please make sure
the communication is as clear as it can be.

## The Community Manager

The Community Manager owns xenproject.org infrastructure. He or she is
responsible for updating various web archives, updating wiki pages and
coordinating with the PR Personnel.

## The PR Personnel

They are responsible for coordinating with external reporters to publish Xen
release announcement. The Release Manager should be absolutely sure the
release is going out on a particular date before giving them the signal to
proceed, because there is a point of no return once they schedule a date with
external reporters.

# What happens during a release

## Development period

Send out monthly update email. The email contains the timeline of the
release, the major work items and any other information the Release Manager
sees fit. Reminders should also be sent one week before important dates (see
above, "last posting date" and "cut-off date"). Please consider adding
relevant events to your calendar.

Occasionally check the status of the xen-unstable branch, make sure it gets
timely pushes to master.

## Freeze period

Before or at very early stage of the freeze period, agree with the Community
Manager a schedule for RC test days.

Once the freeze starts, the ownership of xen-unstable branch automatically
transfers to the Release Manager. The Release Manager can say "not releasing
now" because of too many bugs, "until someone fixes these", or "no more
patches until X, Y, and Z happen".

Here is a list of things to do for making RCs:

1. Check the status of the tree. Ask the Release Technician to make an RC if
the tree is good.

2. Send an email to xen-devel, xen-users and xen-announce to announce the RC.

3. Branch and / or reopen the tree for further feature submission if
appropriate.

4. Collect and track any issues reported, determine their severity, prod
relevant developers and maintainers to fix the issues.

5. When patches to fix issues are posted, determine if the patches are good to
be included.

6. Go back to 1.

It is normally OK in the early RCs that you hand back xen-unstable branch to
committers so that they can commit bug fixes at will. As we approach late
RCs, the standard for accepting a patch will get higher and higher. Please
communicate clearly when committers can commit at will and when formal
Release Ack is needed.

At the same time, work with the Community Manager, PR Personnel and
Contributors to gather a list of features for the release. Discuss the
support status of new features with stakeholders. Help prepare the press
release, write a blog post for the release.

When you think all pending issues are fixed and Xen is ready to be released
from the last RC:

1. Send out commit moratorium emails to committers@.

2. Check all the trees (mini-os, qemu-trad, qemu-xen, seabios, ovmf etc).
They have the correct commits and all security patches applied. There will be
tools provided.

3. Select the release date.

4. Check with relevant stake-holders (typically community manager) whether
wiki documentation and PR is in good shape (for an example see
https://wiki.xenproject.org/wiki/Category:Xen_4.9
<https://wiki.xenproject.org/wiki/Category:Xen_4.9>)

5. Obtain a formal go-ahead from

    * the Community Manager
    * the Release Technician

    Ask them to dry-run their checklist and confirm everything is OK. If not,
    arrange another RC and restart this checklist.

6. Give PR Personnel go-ahead, and instruct Release Technician to make
release deliverables (tags and tarballs - will usually be in place the day
before the release).

7. Make the announcement on various mailing list, publish the blog post.

Allow for contingencies. It is not uncommon that some last minute (security or
not) bugs are discovered. To provide a fix takes time, the test of the fix
will also take time. Allow for at least 1 week from getting a fix to getting
a push. For security bugs, coordinate with the Security Team to adjust the
dates according to our security policy.

## Hand over of Release Manager responsibility

If there is a new Release Manager for the next release, make sure the
following things happen for the new Release Manager.

1. A JIRA (xenproject.atlassian.net) is created and proper permissions granted.
2. Access to community test infrastructure is granted.
3. Access to mailing list moderation panel is granted.
4. An account for blog.xenproject.org is created.
5. An account for wiki.xenproject.org is created.

# Email templates and scripts

Note: if you want specific actions from committers, please make sure you CC
committers@.

## RC emails

```
Subject: Xen X.Y rcZ

Hi all,

Xen X.Y rcZ is tagged. You can check that out from xen.git:

git://xenbits.xen.org/xen.git X.Y.0-rcZ

For your convenience there is also a tarball at:
https://downloads.xenproject.org/release/xen/X.Y.0-rcZ/xen-X.Y.0-rcZ.tar.gz

And the signature is at:
https://downloads.xenproject.org/release/xen/X.Y.0-rcZ/xen-X.Y.0-rcZ.tar.gz.sig

Please send bug reports and test reports to xen-devel@xxxxxxxxxxxxxxxxxxxx.
When sending bug reports, please CC relevant maintainers and me
(abc@xxxxxxx).

As a reminder, there will be another Xen Test Day.

See instructions on: URL_TO_TEST_INSTRUCTIONS
```

## Forego control of the tree

```
Subject: No Release Ack needed before RcX

Committers,

The tree is in good state. No release ack is needed before RcX. Please commit
bug fixes at will.

$RM
```

## Commit moratorium

```
Subject: Commit moratorium for $REASON

Committers,

Please don't push any new patch to staging because $REASON.

Another email will be sent once the moratorium is lifted.

$RM
```

## Lift commit moratorium

```
Subject: Commit moratorium is lifted for $REASON

Committers,

The commit moratorium is lifted, please commit patches that are already
Release-acked.

$RM
```

## Reminder of last posting date

```
Subject: Last posting date for Xen X.Y is $DATE

Hi all,

The last posting date for Xen X.Y is $DATE. If you want your features to be
included for the release, please make sure they are posted for the first
time before $DATE.

$RM
```

## Reminder of cut-off date

```
Subject: Cut-off date for Xen X.Y is $DATE

Hi all,

The cut-off date for Xen X.Y is $DATE. If you want your features to be
included for the release, please make sure they are committed by $DATE.

$RM
```

## Release announcement

```
 Subject: [ANNOUNCEMENT] Xen X.Y is released

 Dear community members,

 I'm pleased to announce that Xen X.Y.0 is released.

 Please find the tarball and its signature at:

 
https://xenproject.org/downloads/xen-archives/xen-project-xy-series/xen-project-xy0.html

 You can also check out the tag in xen.git:

   https://xenbits.xen.org/git-http/xen.git RELEASE-X.Y.0

 Git checkout and build instructions can be found at:

 
https://wiki.xenproject.org/wiki/Xen_Project_X.Y_Release_Notes#Build_Requirements

 Release notes can be found at:

   https://wiki.xenproject.org/wiki/Xen_Project_X.Y_Release_Notes

 A summary for X.Y release documents can be found at:

   https://wiki.xenproject.org/wiki/Category:Xen_X.Y

 Technical blog post for X.Y can be found at:

  URL_TO_BLOG

 Thanks everyone who contributed to this release. This release would
 not have happened without all the awesome contributions from around
 the globe.

 Regards,

 $RM (on behalf of the Xen Project Hypervisor team)
```


## Script to generate months update emails

```
#!/bin/bash
# Use ssmtp for simplicity
# ./xen | formail -f -s /usr/sbin/sendmail -bm -t

FILE=`mktemp`
cat << EOF > $FILE

== Hypervisor ==

S: Boot Xen on EFI platforms using GRUB2 (multiboot2 protocol)
O: Daniel Kiper
E: dkiper@xxxxxxxxxxxx

=== x86 ===

=== ARM ===

== Toolstack ==

EOF


AWK_FILE=`mktemp`
cat << EOF > $AWK_FILE
BEGIN { s2_count = 1;score = ""; emails=1; first_time = 1; subject=""}
/== /  {
        if ( subject != "" )  {
                if (score != "")
                        print "* ", subject,  "("score")"
                else
                        print "* ", subject;
                for (i = 1; i <= s2_count; i++) {
                        if (i in s2)
                                print " ",s2[i];
                }
                for (i = 1; i <= count; i++) {
                        if (i in o)
                                print "  -", o[i]
                }
                if (emails)
                        print ""
                first_time = 1;
                subject=""
                email=""
                score=""
                count = 1;
                s2_count = 1;
                delete s;
                delete s2;
                delete o;
                delete e;
        }
        print \$0,"\n"
        }
/;/ { };
/S:/    {
        if ( !first_time )  {
                if (score != "")
                        print "* ", subject,  "("score")"
                else
                        print "* ", subject
                for (i = 1; i <= s2_count; i++) {
                        if (i in s2)
                                print " ",s2[i];
                }
                for (i = 1; i <= count; i++) {
                        if (i in o)
                                print "  -", o[i]
                }
                if (emails)
                        print ""
        }
        first_time = 0;
        sub(\$1, "");
        sub(/^[ \t]+/, "");
        subject=\$0;
        email=""
        count = 1;
        s2_count = 1;
        delete s;
        delete s2;
        delete o;
        delete e;
        score="";
        }
/O:/    { sub(\$1, ""); o[count++]=\$0; };
/S2:/   { sub(\$1, ""); s2[s2_count++]=\$0;};
/E:/    { sub(\$1, ""); sub(/^[ \t]+/, ""); email=\$0; e[emails++]=\$0;};
/P:/    { sub(\$1, ""); sub(/^[ \t]+/, ""); score=\$0; };
END     {
        }
// {  }
EOF
AWK_FILE_EMAIL=`mktemp`
cat << EOF > $AWK_FILE_EMAIL
BEGIN { emails=1;}
/E:/    {
        sub(\$1, ""); sub(/^[ \t]+/, "");
        email=\$0;
        for ( i = 1; i <= emails; i++ ) {
                if (i in e) {
                        if (e[i] == email) {
                                email="";
                                break;
                        }
                }
        }
        if (email != "")
                e[emails++]=email;
}
END     {
        printf "Bcc: "
        for ( i = 1; i <= emails; i++ )
                if (i in e) {
                        if (i == emails - 1)
                                printf "<%s>", e[i];
                        else
                                printf "<%s>,", e[i];
                }
        print ""
        }
// {  }
EOF

echo "From: abc@xxxxxxx"
echo "To: xen-devel@xxxxxxxxxxxxxxxxxxxx"
echo "Cc: abc@xxxxxxx"
cat $FILE | awk -f $AWK_FILE_EMAIL
rm $AWK_FILE_EMAIL

echo "Subject: Xen $XEN_RELEASE Development Update"
PRE=`mktemp`
cat << EOF > $PRE

This email only tracks big items for xen.git tree. Please reply for items you
woulk like to see in $XEN_RELEASE so that people have an idea what is going on 
and
prioritise accordingly.

You're welcome to provide description and use cases of the feature you're
working on.

= Timeline =

We now adopt a fixed cut-off date scheme. We will release twice a
year. The upcoming $XEN_RELEASE timeline are as followed:

* Last posting date: $LAST_POSTING_DATE
* Hard code freeze: $CUT_OFF_DATE
* RC1: TBD
* Release: $RELEASE_DATE

Note that we don't have freeze exception scheme anymore. All patches
that wish to go into $XEN_RELEASE must be posted no later than the last posting
date. All patches posted after that date will be automatically queued
into next release.

RCs will be arranged immediately after freeze.

= Projects =

EOF

# Preamble
cat $PRE
rm $PRE
# Body
cat $FILE | awk -f $AWK_FILE
rm $AWK_FILE
rm $FILE
````

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