Remove Pro advertising from Apt

Project Discussion Ubuntu Pro
2

I wasted my entire morning trying to unconfigure the ESM messages that are displayed at each login over and over again.
The messages that I want to stop from appearing are:

Expanded Security Maintenance for Applications is not enabled.

Enable ESM Apps to receive additional future security updates.
See https://ubuntu.com/esm or run: sudo pro status

I followed the hints, that I read in

The official documentation led me to:

How are the APT messages generated?

`apt-esm-hook` and `apt-esm-json-hook` in config file: `/etc/apt/apt.conf.d/20apt-esm-hook.conf`

We have two distinct apt hooks that allow us to deliver these messages when you run apt upgrade or apt dist-upgrade. They are:

apt-esm-hook

Responsible for populating templates with accurate package counts (i.e. the package count we see on the Expired contract messages). However, the messaging here is created by two distinct steps:

  1. Our update_messages timer job creates templates for the APT messages this hook will deliver. We cannot create the full message on the timer job, because we need the accurate package names and count. This information can only be obtained when running the apt command.

Note

These templates will only be produced if certain conditions are met. For example, we only produce “expired contract” templates if the contracts are indeed expired.

  1. When you run either apt upgrade or apt dist-upgrade, the hook searches for these templates and if they exist, they are populated with the correct apt content and delivered to the user.

apt-esm-json-hook

The JSON hook is responsible for delivering the rest of the message we have presented here. This hook is used to inject the message in the exact place we want, so we need to use a specific apt JSON hook to communicate with it.

Note

Those hooks are only delivered on LTS releases. This is because the hooks will not deliver useful messages on non-LTS due to lack of support for ESM services.

How are APT configured to deliver those messages?

We currently ship the package the 20apt-esm-hook.conf configuration that configures both the basic apt hooks to call our apt-esm-hook binary, and also the json API of apt to call our apt-esm-json-hook binary.

So I did just that, I commented out the two hooks.

Commented out hooks in file: `20apt-esm-hook.conf`

$ cat /etc/apt/apt.conf.d/20apt-esm-hook.conf
APT::Update::Pre-Invoke {
“[ ! -e /run/systemd/system ] || [ $(id -u) -ne 0 ] || systemctl start --no-block apt-news.service esm-cache.service || true”;
};

APT::Update::Post-Invoke-Stats {
# Disable ESM messages
# “[ ! -f /usr/lib/ubuntu-advantage/apt-esm-hook ] || /usr/lib/ubuntu-advantage/apt-esm-hook || true”;
};

binary::apt::AptCli::Hooks::Upgrade {
# Disable ESM messages
# “[ ! -f /usr/lib/ubuntu-advantage/apt-esm-json-hook ] || /usr/lib/ubuntu-advantage/apt-esm-json-hook || true”;
};

I rebooter and low and behold,…
Nothing changed

I’ve tested this on a headless Raspberry Pi running: Ubuntu Server 22.04.2 LTS (GNU/Linux 5.15.0-1026-raspi armv7l)

Some helpful tips for people wanting to try for themselves what I did.

The annoying messages are generated as part of the dynamic motd generation (update-motd package).
This service executes /etc/update-motd.d/90-updates-available.
You can test generation of the MOTD scripts with:

$ sudo run-parts /etc/update-motd.d/

On its turn motd.d shows a cached result.
That result was generated by update-notifier and cached in:
“/var/lib/update-notifier/updates-available”
by python script:
/usr/lib/update-notifier/apt_check.py
One can force the generation of the file by doing:

$ sudo /usr/lib/update-notifier/update-motd-updates-available --force

Verify removal of esm apt config with:

$ apt-config dump|grep esm

How can one elegantly unconfigure the messages from appearing at each login?

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