bad test for snappy systems

[Steve Langasek]

Reviewing the latest SRU for cloud-init, I noticed the following:

def system_is_snappy():
    # channel.ini is configparser loadable.
    # snappy will move to using /etc/system-image/config.d/*.ini
    # this is certainly not a perfect test, but good enough for now.
    content = load_file("/etc/system-image/channel.ini", quiet=True)
    if 'ubuntu-core' in content.lower():
        return True
    if os.path.isdir("/etc/system-image/config.d/"):
        return True
    return False

This isn't a good test for whether a system is an ubuntu-core system. 'system-image' is historical baggage, and not likely to be present at all in future versions.

I'm afraid I don't know a good alternative test offhand, but wanted to log the bug so someone could look into it rather than being caught by surprise when ubuntu-core image contents later change.

[Ryan Harper (raharper)]

This issue was fixed a while back in:

https://github.com/canonical/cloud-init/commit/4bcc94730

cloud-init retains the legacy bits, but prefers the use of os-release file or kernel commandline to for checking for UbuntuCore.

[James Falcon (falcojr)]

Tracked in Github Issues as https://github.com/canonical/cloud-init/issues/2757