Comment 33 for bug 1686183

To summarize, as expected, all non-precise releases behave the same:

a) enable-esm fails with a valid token because ESM is not available for non-precise ubuntu releases. That causes apt-get update to fail with a 404. The situation is resolved by running the disable-esm command.

b) MOTD gets no ubuntu-advantage or esm related messages, regardless if esm is enabled or not. This is correct, since esm is only available for precise, and ubuntu-advantage has no other functionality.

After having done the above passes on trusty, xenial and zesty, I decided to take another pass and verify that if ca-certificates or apt-transport-https are missing, that ubuntu-advantage would install them. This already happens on precise, but maybe the package names or dependencies changed in other releases.

To properly test this I configured apt to not install recommends by default, otherwise just by installing apt-transport-https we would already get ca-certificates. I'm going to update the [Test Case] section of this SRU about this extra test and its preparation:

$ cat /etc/apt/apt.conf.d/no-recommends
APT::Install-Recommends "false";

Here are the results:

a) zesty:
ubuntu@zesty-ubuntu-advantage:~$ sudo ubuntu-advantage enable-esm <redacted>
Installing missing dependency apt-transport-https
Installing missing dependency ca-certificates
Running apt-get update...
(...)

b) xenial:
ubuntu@xenial-ubuntu-advantage:~$ sudo ubuntu-advantage enable-esm <redacted>
Installing missing dependency apt-transport-https
Installing missing dependency ca-certificates
Running apt-get update...
(...)

c) trusty:
ubuntu@trusty-ubuntu-advantage-1686183:~$ sudo ubuntu-advantage enable-esm <redacted>
Installing missing dependency apt-transport-https
Installing missing dependency ca-certificates
Running apt-get update...
(...)