trusty upgrade to xenial will show esm-infra as disabled

[lucasmoura]

When we are attached to a trusty machine and we perform a do-release-upgrade operation we expect to be upgraded to xenial while keeping esm-infra, or any other service we have enabled, still enabled. We guarantee that by running the upgrade_lts_contract in the end of do-release-upgrade. This is script is run by adding the following configuration at /etc/update-manager/release-upgrades.d/

[Sources]
Pockets=security,updates,proposed,backports,infra-security,infra-updates,apps-security,apps-updates
[Distro]
PostInstallScripts=./xorg_fix_proprietary.py, /usr/lib/ubuntu-advantage/upgrade_lts_contract.py

In our current testing infrastructure, we are updating the tusty packaging to the development version of uaclient and then performing the upgrade. This will guarantee that will we have that file in place before running do-release-upgrade. Now, since we will not release the new uaclient version into trusty, we will never have that configuration in place. This means that do-release-upgrade will not run the upgrade_lts_script in the end, which in turn, will make esm-infra to be disabled, as the apt sources will not be correctly updated.

[lucasmoura]

We two workarounds for this:

1. Manually add the etc/update-manager/release-upgrades.d/ config:

[Sources]
Pockets=security,updates,proposed,backports,infra-security,infra-updates,apps-security,apps-updates
[Distro]
PostInstallScripts=./xorg_fix_proprietary.py, /usr/lib/ubuntu-advantage/upgrade_lts_contract.py

Before running do-release-upgrade

2. After running do-release-upgrade and restarting the machine, run ua enable esm-infra

[mitechie]

Documented as an FAQ item in https://discourse.ubuntu.com/t/ubuntu-advantage-client/21788/4

[orndorffgrant]

Closing as a Won't Fix because it is documented.