Ntp schema definition permits empty ntp cloud-config, but code disallows

Bug Description

http://pad.lv/1724951
https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1724951

=== Begin SRU Template ===
[Impact]
Customers who provide the following cloud-config will get a Runtime error
#cloud-config
ntp:

The expected behavior, per docs, is that an empty ntp configuration will result in
"4 pools will be used in the format {0-3}.{distro}.pool.ntp.org.".

[Test Case]

if [ ! -f './lxc-proposed-snapshot' ]; then
wget https://raw.githubusercontent.com/cloud-init/ubuntu-sru/master/bin/lxc-proposed-snapshot;
chmod 755 lxc-proposed-snapshot;
fi

# 1. Provide a empty ntp configuration to cloud-init
cat > install-ntp.conf <<EOF
#cloud-config
ntp:
EOF

# 2.
for release in xenial zesty artful; do
ref=$release-proposed;
echo "$release START --------------";
lxc-proposed-snapshot --proposed --publish $release $ref;
lxc init $ref test-$release;
lxc config set test-$release user.user-data - < install-ntp.conf;
lxc start test-$release;
sleep 10;
# no runtime error
lxc exec test-$release -- cat /run/cloud-init/result.json
# ntp installed
lxc exec test-$release -- dpkg-query --show ntp;
# default pools
lxc exec test-$release -- grep pool /etc/ntp.conf
done

[Regression Potential]
Minimal, this fixes only a corner case where cloud-config ntp specified is completely empty.
Any more complex ntp configuration are unaffected by code changes.

[Other Info]
Upstream commit at
https://git.launchpad.net/cloud-init/commit/?id=6bc504e41666

=== End SRU Template ===

An upload of cloud-init to xenial-proposed has been rejected from the upload queue for the following reason: "Please re-upload including the changelog entries from the unreleased version in -proposed in the .changes file. Thanks!".

An upload of cloud-init to zesty-proposed has been rejected from the upload queue for the following reason: "Please re-upload including the changelog entries from the unreleased version in -proposed in the .changes file. Thanks!".

Hello Chad, or anyone else affected,

Accepted cloud-init into artful-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/cloud-init/17.1-25-g17a15f9e-0ubuntu1~17.10.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-artful to verification-done-artful. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-artful. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Hello Chad, or anyone else affected,

Accepted cloud-init into zesty-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/cloud-init/17.1-25-g17a15f9e-0ubuntu1~17.04.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-zesty to verification-done-zesty. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-zesty. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Hello Chad, or anyone else affected,

Accepted cloud-init into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/cloud-init/17.1-25-g17a15f9e-0ubuntu1~16.04.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

xenial START --------------
creating xenial-proposed-226181656
[sudo] password for csmith:
--proposed --
...
Get:1 http://archive.ubuntu.com/ubuntu xenial-proposed/main amd64 cloud-init all 17.1-25-g17a15f9e-0ubuntu1~16.04.1 [342 kB]
...
{
"v1": {
"datasource": "DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]",
"errors": []
}
}
ntp 1:4.2.8p4+dfsg-3ubuntu5.7
# on 2011年02月08日 (LP: #104525). See http://www.pool.ntp.org/join.html for
# pools
pool 0.ubuntu.pool.ntp.org iburst
pool 1.ubuntu.pool.ntp.org iburst
pool 2.ubuntu.pool.ntp.org iburst
pool 3.ubuntu.pool.ntp.org iburst
# pool ntp.ubuntu.com
# Needed for adding pool entries

Creating zesty-proposed-312292735
--proposed --
...
Get:1 http://archive.ubuntu.com/ubuntu zesty-proposed/main amd64 cloud-init all 17.1-25-g17a15f9e-0ubuntu1~17.04.1 [339 kB]
...
{
"v1": {
"datasource": "DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]",
"errors": []
}
}
ntp 1:4.2.8p9+dfsg-2ubuntu1.2
# on 2011年02月08日 (LP: #104525). See http://www.pool.ntp.org/join.html for
# pools
pool 0.ubuntu.pool.ntp.org iburst
pool 1.ubuntu.pool.ntp.org iburst
pool 2.ubuntu.pool.ntp.org iburst
pool 3.ubuntu.pool.ntp.org iburst
# pool ntp.ubuntu.com
# Needed for adding pool entries

artful START --------------
Creating artful-proposed-85532394
...
Get:1 http://archive.ubuntu.com/ubuntu artful-proposed/main amd64 cloud-init all 17.1-25-g17a15f9e-0ubuntu1~17.10.1 [333 kB]
...
{
"v1": {
"datasource": "DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]",
"errors": []
}
}
ntp 1:4.2.8p10+dfsg-5ubuntu3
# on 2011年02月08日 (LP: #104525). See http://www.pool.ntp.org/join.html for
# pools
pool 0.ubuntu.pool.ntp.org iburst
pool 1.ubuntu.pool.ntp.org iburst
pool 2.ubuntu.pool.ntp.org iburst
pool 3.ubuntu.pool.ntp.org iburst
# pool ntp.ubuntu.com
# Needed for adding pool entries

=== End Abridged SRU verifcation output ===

This bug was fixed in the package cloud-init - 17.1-25-g17a15f9e-0ubuntu1~17.10.1

---------------
cloud-init (17.1-25-g17a15f9e-0ubuntu1~17.10.1) artful-proposed; urgency=medium

* New upstream snapshot.
- resizefs: Fix regression when system booted with root=PARTUUID=
(LP: #1725067)
- tools: make yum package installation more reliable
- citest: fix remaining warnings raised by integration tests.
- citest: show the class actual class name in results.
- ntp: fix config module schema to allow empty ntp config
(LP: #1724951)
- tools: disable fastestmirror if using proxy [Joshua Powers]
- schema: Log debug instead of warning when jsonschema is not available.
(LP: #1724354)

-- Chad Smith <email address hidden> 2017年10月23日 15:07:35 -0600

The verification of the Stable Release Update for cloud-init has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

Hello Chad, or anyone else affected,

Accepted cloud-init into zesty-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/cloud-init/17.1-27-geb292c18-0ubuntu1~17.04.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-zesty to verification-done-zesty. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-zesty. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Hello Chad, or anyone else affected,

Accepted cloud-init into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/cloud-init/17.1-27-geb292c18-0ubuntu1~16.04.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

=== Abridged SRU verifcation output ===
$ for release in xenial zesty artful; do
> ref=$release-proposed;
> echo "$release START --------------";
> lxc-proposed-snapshot -p -P $release $ref;
> lxc init $ref test-$release;
> lxc config set test-$release user.user-data - < install-ntp.conf;
> lxc start test-$release;
> sleep 10;
> lxc exec test-$release -- cat /run/cloud-init/result.json
> lxc exec test-$release -- dpkg-query --show ntp;
> lxc exec test-$release -- grep pool /etc/ntp.conf
> done
xenial START --------------
Creating xenial-proposed-115658625
...
Get:1 http://archive.ubuntu.com/ubuntu xenial-proposed/main amd64 cloud-init all 17.1-27-geb292c18-0ubuntu1~16.04.1 [341 kB]
Creating test-xenial

{
"v1": {
"datasource": "DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]",
"errors": []
}
}
ntp 1:4.2.8p4+dfsg-3ubuntu5.7
# on 2011年02月08日 (LP: #104525). See http://www.pool.ntp.org/join.html for
# pools
pool 0.ubuntu.pool.ntp.org iburst
pool 1.ubuntu.pool.ntp.org iburst
pool 2.ubuntu.pool.ntp.org iburst
pool 3.ubuntu.pool.ntp.org iburst
# pool ntp.ubuntu.com
# Needed for adding pool entries

zesty START --------------
Creating zesty-proposed-63815953
...
Get:1 http://archive.ubuntu.com/ubuntu zesty-proposed/main amd64 cloud-init all 17.1-27-geb292c18-0ubuntu1~17.04.1 [339 kB]
...
Creating test-zesty
{
"v1": {
"datasource": "DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]",
"errors": []
}
}
ntp 1:4.2.8p9+dfsg-2ubuntu1.2
# on 2011年02月08日 (LP: #104525). See http://www.pool.ntp.org/join.html for
# pools
pool 0.ubuntu.pool.ntp.org iburst
pool 1.ubuntu.pool.ntp.org iburst
pool 2.ubuntu.pool.ntp.org iburst
pool 3.ubuntu.pool.ntp.org iburst
# pool ntp.ubuntu.com
# Needed for adding pool entries

artful START --------------
Creating artful-proposed-1092522261
...
Get:1 http://archive.ubuntu.com/ubuntu artful-proposed/main amd64 cloud-init all 17.1-27-geb292c18-0ubuntu1~17.10.1 [332 kB]
...
Creating test-artful
{
"v1": {
"datasource": "DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]",
"errors": []
}
}
ntp 1:4.2.8p10+dfsg-5ubuntu3
# on 2011年02月08日 (LP: #104525). See http://www.pool.ntp.org/join.html for
# pools
pool 0.ubuntu.pool.ntp.org iburst
pool 1.ubuntu.pool.ntp.org iburst
pool 2.ubuntu.pool.ntp.org iburst
pool 3.ubuntu.pool.ntp.org iburst
# pool ntp.ubuntu.com
# Needed for adding pool entries
=== End Abridged SRU verifcation output ===

This bug was fixed in the package cloud-init - 17.1-27-geb292c18-0ubuntu1~17.04.1

---------------
cloud-init (17.1-27-geb292c18-0ubuntu1~17.04.1) zesty-proposed; urgency=medium

* New upstream snapshot.
- EC2: Limit network config to fallback nic, fix local-ipv4 only
instances. (LP: #1728152)
- Gentoo: Use "rc-service" rather than "service". [Carlos Konstanski]

cloud-init (17.1-25-g17a15f9e-0ubuntu1~17.04.1) zesty-proposed; urgency=medium

* New upstream snapshot.
- resizefs: Fix regression when system booted with root=PARTUUID=
(LP: #1725067)
- tools: make yum package installation more reliable
- citest: fix remaining warnings raised by integration tests.
- citest: show the class actual class name in results.
- ntp: fix config module schema to allow empty ntp config
(LP: #1724951)
- tools: disable fastestmirror if using proxy [Joshua Powers]

cloud-init (17.1-18-gd4f70470-0ubuntu1~17.04.2) zesty-proposed; urgency=medium

* cherry-pick 41152f1: schema: Log debug instead of warning when
jsonschema is absent (LP: #1724354)

cloud-init (17.1-18-gd4f70470-0ubuntu1~17.04.1) zesty-proposed; urgency=medium

* drop the following cherry picks, now incorporated in snapshot.
+ debian/patches/cpick-a2f8ce9c-Do-not-provide-systemd-fsck-drop...
* debian/copyright: dep5 updates, reorganize, add Apache 2.0 license.
(LP: #1718681)
* debian/control: drop dependency on python3-prettytable
* debian/rules: install rsyslog file with 0644 mode instead of 0755.
* debian/rules, debian/apport-launcher.py: add an apport hook. (LP: #1607345)
* New upstream snapshot (LP: #1721847)
- simpletable: Fix get_string method to return table-formatted string
- net: Handle bridge stp values of 0 and convert to boolean type
[Chad Smith]
- tools: Give specific --abbrev=8 to "git describe"
- network: bridge_stp value not always correct [Ryan Harper]
- tests: re-enable tox with nocloud-kvm support [Joshua Powers]
- systemd: remove limit on tasks created by cloud-init-final.service.
[Robert Schweikert]
- suse: Support addition of zypper repos via cloud-config.
[Robert Schweikert]
- tests: Combine integration configs and testcases [Joshua Powers]
- Azure, CloudStack: Support reading dhcp options from systemd-networkd.
[Dimitri John Ledkov]
- packages/debian/copyright: remove mention of boto and MIT license
- systemd: only mention Before=apt-daily.service on debian based distros.
[Robert Schweikert]
- Add missing simpletable and simpletable tests for failed merge
[Chad Smith]
- Remove prettytable dependency, introduce simpletable [Andrew Jorgensen]
- debian/copyright: dep5 updates, reorganize, add Apache 2.0 license.
[Joshua Powers]
- tests: remove dependency on shlex [Joshua Powers]
- AltCloud: Trust PATH for udevadm and modprobe.
- DataSourceOVF: use util.find_devs_with(TYPE=iso9660)
[Ryan Harper]
- tests: remove a temp file used in bootcmd tests.
- release 17.1
- doc: document GCE datasource. [Arnd Hannemann]
- suse: updates to templates to support openSUSE and SLES.
[...

This bug was fixed in the package cloud-init - 17.1-27-geb292c18-0ubuntu1~16.04.1

---------------
cloud-init (17.1-27-geb292c18-0ubuntu1~16.04.1) xenial-proposed; urgency=medium

* New upstream snapshot.
- EC2: Limit network config to fallback nic, fix local-ipv4 only
instances. (LP: #1728152)
- Gentoo: Use "rc-service" rather than "service". [Carlos Konstanski]

cloud-init (17.1-25-g17a15f9e-0ubuntu1~16.04.1) xenial-proposed; urgency=medium

* New upstream snapshot.
- resizefs: Fix regression when system booted with root=PARTUUID=
(LP: #1725067)
- tools: make yum package installation more reliable
- citest: fix remaining warnings raised by integration tests.
- citest: show the class actual class name in results.
- ntp: fix config module schema to allow empty ntp config
(LP: #1724951)
- tools: disable fastestmirror if using proxy [Joshua Powers]

cloud-init (17.1-18-gd4f70470-0ubuntu1~16.04.2) xenial-proposed; urgency=medium

* cherry-pick 41152f1: schema: Log debug instead of warning when
jsonschema is absent (LP: #1724354)

cloud-init (17.1-18-gd4f70470-0ubuntu1~16.04.1) xenial-proposed; urgency=medium

* drop the following cherry picks, now incorporated in snapshot.
+ debian/patches/cpick-a2f8ce9c-Do-not-provide-systemd-fsck-drop...
* debian/copyright: dep5 updates, reorganize, add Apache 2.0 license.
(LP: #1718681)
* debian/control: drop dependency on python3-prettytable
* debian/rules: install rsyslog file with 0644 mode instead of 0755.
* debian/rules, debian/apport-launcher.py: add an apport hook. (LP: #1607345)
* New upstream snapshot. (LP: #1721847)
- simpletable: Fix get_string method to return table-formatted string
- net: Handle bridge stp values of 0 and convert to boolean type
[Chad Smith]
- tools: Give specific --abbrev=8 to "git describe"
- network: bridge_stp value not always correct [Ryan Harper]
- tests: re-enable tox with nocloud-kvm support [Joshua Powers]
- systemd: remove limit on tasks created by cloud-init-final.service.
[Robert Schweikert]
- suse: Support addition of zypper repos via cloud-config.
[Robert Schweikert]
- tests: Combine integration configs and testcases [Joshua Powers]
- Azure, CloudStack: Support reading dhcp options from systemd-networkd.
[Dimitri John Ledkov]
- packages/debian/copyright: remove mention of boto and MIT license
- systemd: only mention Before=apt-daily.service on debian based distros.
[Robert Schweikert]
- Add missing simpletable and simpletable tests for failed merge
[Chad Smith]
- Remove prettytable dependency, introduce simpletable [Andrew Jorgensen]
- debian/copyright: dep5 updates, reorganize, add Apache 2.0 license.
[Joshua Powers]
- tests: remove dependency on shlex [Joshua Powers]
- AltCloud: Trust PATH for udevadm and modprobe.
- DataSourceOVF: use util.find_devs_with(TYPE=iso9660)
[Ryan Harper]
- tests: remove a temp file used in bootcmd tests.
- release 17.1
- doc: document GCE datasource. [Arnd Hannemann]
- suse: updates to templates to support openSUSE and SLES.
...

This bug is believed to be fixed in cloud-init in 1705804. If this is still a problem for you, please make a comment and set the state back to New

Thank you.

Tracked in Github Issues as https://github.com/canonical/cloud-init/issues/3035