Amazon Linux 2 ansible_distribution_version fact not parsed correctly

[gizmonicus]

SUMMARY

Amazon Linux 2 has changed the string they use in the /etc/system-release file. Previously, it did not have a "codename", but it does now. This breaks ansible_distribution_version fact.

# before the update
Amazon Linux release 2
# after the update
Amazon Linux release 2 (Karoo)

Because this code...

ansible/lib/ansible/module_utils/facts/system/distribution.py

Line 224 in c5b303f

amazon_facts['distribution_version'] = data.split()[-1]

...splits this string on spaces and uses -1 as the index, ansible_distribution_version is set to (Karoo) instead of the expected value 2. I am using ansible 2.5.10, but have confirmed the master branch has the same code for parsing the Amazon Linux version number.

I have noticed that Amazon Linux and Amazon Linux 2 both now have an /etc/os-release file that looks like it would be easier to parse and less prone to breakage when these types of changes occur. I suspect that wasn't the case when distribution.py was written.

I also noticed that if you remove /etc/system-release you can allow distribution.py to fall back to the default parser mode, and it is able to correctly determine the version in both cases (Amazon Linux 1/2), but the ansible_distribution_name does not get correctly set. I've looked into modifying the code to support /etc/os-release parsing on Amazon Linux distributions, but have not been successful yet.

ISSUE TYPE

• Bug Report

COMPONENT NAME

Ansible facts module

ANSIBLE VERSION

ansible 2.5.10
  config file = /home/cliff/workspace/wfu.ansible/ansible.cfg
  configured module search path = [u'/home/cliff/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /home/cliff/.virtualenvs/ansible/lib/python2.7/site-packages/ansible
  executable location = /home/cliff/.virtualenvs/ansible/bin/ansible
  python version = 2.7.15 (default, Jun 27 2018, 13:05:28) [GCC 8.1.1 20180531]

CONFIGURATION

DEFAULT_BECOME(/home/user/workspace/ansible/ansible.cfg) = True
DEFAULT_BECOME_USER(/home/user/workspace/ansible/ansible.cfg) = root
DEFAULT_HOST_LIST(/home/user/workspace/ansible/ansible.cfg) = [u'/home/user/workspace/ansible/inventory.yml']
DEFAULT_VAULT_PASSWORD_FILE(env: ANSIBLE_VAULT_PASSWORD_FILE) = /home/user/.ansible-vault
DIFF_ALWAYS(/home/user/workspace/ansible/ansible.cfg) = True
HOST_KEY_CHECKING(/home/user/workspace/ansible/ansible.cfg) = False
RETRY_FILES_ENABLED(/home/user/workspace/ansible/ansible.cfg) = False

OS / ENVIRONMENT

Target OS: AWS Amazon Linux 2
Kernel: 4.14.72-73.55.amzn2.x86_64

The package containing the new /etc/system-release file is 1:system-release-2-7.amzn2.x86_64.

STEPS TO REPRODUCE

To reproduce, spin up an AWS EC2 instance with Amazon Linux 2 installed. Be sure the package mentioned in the OS / Environment section is installed. Then run:

ansible -m setup hostname | grep ansible_distribution_version

EXPECTED RESULTS

We expect to see 2 as the version number.

ACTUAL RESULTS

You will see (karoo) as the version.

[ansibot]

Hi @gizmonicus, thank you for submitting this issue!

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[ansibot]

Files identified in the description:

• lib/ansible/module_utils/facts

If these files are inaccurate, please update the component name section of the description or use the !component bot command.

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[chadmiller-amzn]

I want to confirm /etc/os_release is the correct file to parse, not the human-legible /etc/system_release.

[tamsky]

My vote is for /etc/os_release

[jmahler]

From info here [1] os-release was established by systemd which suggests
it isn't guaranteed to be present on pre-systemd systems.

A solution that uses /etc/os-release if possible and falls back to /etc/system-release
otherwise would avoid potential backward incompatibilities.

[1] http://0pointer.de/blog/projects/os-release.html

[ansibot]

@gizmonicus: Greetings! Thanks for taking the time to open this issue. In order for the community to handle your issue effectively, we need a bit more information.

Here are the items we could not find in your description:

• issue type
• ansible version
• component name

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[maximede]

Hello ! Would you accept a PR to backport the fix (#51521) in the stable-2.5 branch ?

[mkrizek]

@maximede No, 2.5 is EOL. Please see https://docs.ansible.com/ansible/latest/reference_appendices/release_and_maintenance.html#release-status to see status for each Ansible version, thanks!