Spams motd with "proxy ... looks invalid"

[Robie Basak]

On login, occasionally I see:

proxy 'http://[<ipv6 address redacted>]:3128/' looks invalid

I tracked this down to /etc/update-motd.d/91-release-upgrade which is calling "/usr/lib/ubuntu-release-upgrader/check-new-release -q" when a cache is stale, and I can reproduce this every time by running "sudo usr/lib/ubuntu-release-upgrader/check-new-release -q".

It looks like UpdateManager/Core/utils.py has an incomplete regexp "http://\w+", which does not catch the square brackets used around an IPv6 address. Presumably the regexp needs extending. In my case I'm specifying my proxy by IP because I use Zeroconf names (using mdns) but in this case am using it inside a container that is bridged so .local names do not resolve there.

This presumably means that it ignores my proxy definition too, though I haven't tested this.

This is with update-manager-core 1:16.04.3 but it looks like the source from 1:16.10.1 is still affected.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Rich McAllister (rfm)]

Similarly, I have set in apt.conf.d

Acquire::https::Proxy "DIRECT";

(because apt-cacher-ng can't cache https) and I get

proxy 'DIRECT' looks invalid

The regexp definitely needs to be broadened.

[Aaron Dude (dudepron+ubuntu)]

So 1 year later and this is still open? I have an IPv6 only network and this is causing me problems.

[Aaron Dude (dudepron+ubuntu)]

This did work going from 14.04 to 16.04

[Jane Atkinson (irihapeti)]

Still happening in Ubuntu server 20.04.1.

I have

Acquire::https::Proxy "DIRECT";

set in apt.conf and I'm getting the message "Proxy 'DIRECT' looks invalid" on logging in.

[Brian Candler (b-candler)]

I am also getting this with 18.04.5 LTS. In /etc/apt/apt.conf.d/99proxy I have:

Acquire::http::Proxy "http://127.0.0.1:3142/";
Acquire::https::Proxy "DIRECT";

and sometimes the the motd displays

proxy 'DIRECT' looks invalid

I have discovered why it's intermittent: that text is the *stderr* output from /usr/lib/ubuntu-release-upgrader/check-new-release -q

This means it doesn't get stored in /var/lib/ubuntu-release-upgrader/release-upgrade-available, because only the *stdout* is redirected there.

Therefore, it only gets displayed at login time when /usr/lib/ubuntu-release-upgrader/release-upgrade-motd is run, and this only performs the check if its previous output is more than 1 day old.

I also note that the script runs "check-new-release -q" in the background (with &), which means that its stderr output could in principle appear later on and be mixed up with other output. Perhaps this is intentional, so that messages like "Failed to connect to https://changelogs.ubuntu.com/meta-release-lts. Check your Internet connection or proxy settings" don't persist in the motd.

But in any case, "DIRECT" is a documented and valid form for proxy, so it should not generate any warning.

[Brian Candler (b-candler)]

Correction: the "Failed to connect..." message appears on stdout anyway, so it *does* persist.

So as a second change, I suggest that /usr/lib/ubuntu-release-upgrader/release-upgrade-motd should capture the stderr as well, by adding "2>&1" before "&"