** Description changed:
[Impact]
The ubuntu-advantage-tools package ("uat", for short) installs by default a
sources.list snippet so that the machine can become aware of available ESM
updates. They cannot be downloaded without authentication, so to prevent them
from being considered in updates, an apt preferences file is also installed
pinning the esm repository down.
Turns out that ESM is only available for the x86 architecture, and
installing that sources.list snippet for other architectures leads to
apt-get update failures.
A mitigation was put in place on the ESM repository to publish an empty
archive for these unsupported architectures, so apt-get update won't
fail.
The change in this SRU adds another case for when postinst configures
and unconfigures ESM, and that is an architecture check via `dpkg
--print-architecture`.
This by itself is not enough to prevent users from trying to enable esm-
infra on non-x86 architectures, as the contract server is still
incorrectly advertising that support. This has been fixed in the staging
deployment and a production deployment with this change should happen
soon as well, completing the fix for this issue.
[Test Case]
# Install the current trusty-updates ubuntu-advantage-tools on a non-x86
system (armhf, arm64, ppc64el, or s390x).
$ sudo apt install ubuntu-advantage-tools
# verify that apt-get update is hitting the esm repository:
$ sudo apt-get update | grep esm
Get:1 https://esm.ubuntu.com trusty-infra-security InRelease
Get:2 https://esm.ubuntu.com trusty-infra-updates InRelease
...
# verify that an esm pinning file was installed. Check that esm.ubuntu.com
shows up in the apt-cache policy output, and that its pinning is negative:
$ apt-cache policy | grep esm
-32768 https://esm.ubuntu.com/ubuntu/ trusty-infra-updates/main ppc64el
Packages
origin esm.ubuntu.com
-32768 https://esm.ubuntu.com/ubuntu/ trusty-infra-security/main ppc64el
Packages
origin esm.ubuntu.com
# upgrade to the ubuntu-advantage-tools package from proposed and repeat the
test. apt-get update shouldn't be hitting the ESm repository anymore, and the
policy output should be empty as well:
$ sudo apt install ubuntu-advantage-tools # from trusty-proposed
- $ apt-get update
+ $ apt-get update | grep esm
<empty>
$ apt-cache policy | grep esm
<empty>
# conversely, on a x86 system, the output should remain the same, i.e.,
esm should be listed and again with a negative pinning
[Regression Potential]
The logic relies on architecture names returned by `dpkg
--print-architecture`. It there is a change in its output, or some other bug,
we could be disabling (or enabling) the esm repository where we shouldn't.
[Other Info]
The knowledge about which architectures are supported is now statically
stored in the package, which is a bit unfortunate. The final authority is the
contract server, and the actual esm repository. This information is sent to the
client, but we are not making a network call in postinst to verify that. One
reason being that the launchpad builders and DEP8 runners block such egress
traffic.
If esm-infra was already enabled before applying the update, it will
become disabled on non-x86 architectures. Since there are no non-x86 ESM
updates available, this is just reflecting the truth about the support.
[Original Description]
The shiny new ubuntu-advantage-tools client adds ESM to sources.list.d
unconditionally on all architectures, but the ESM archive itself currently only
publishes for x86. One of those two things is a bug.
Personally, I think it's a bug we don't publish ESM for all the same
arches as we released for (even if we don't update all the packages for
all arches, people would at least get things like tzdata updates), but
if the intent is to be strictly x86-only, then ubuntu-advantage-tools is
very much in the wrong here, as it creates a situation where apt-get
update fails on all !x86.
--
You received this bug notification because you are a member of Ubuntu
Server, which is subscribed to ubuntu-advantage-tools in Ubuntu.
https://bugs.launchpad.net/bugs/1851858
Title:
adds ESM to sources.list.d unconditionally, despite it being x86-only
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu-advantage-script/+bug/1851858/+subscriptions
--
Ubuntu-server-bugs mailing list
Ubuntu-server-bugs@lists.ubuntu.com
Modify settings or unsubscribe at:
https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
