update pkg_mgr.py for Amazon Linux support

[huntertj]

SUMMARY

ansible_distribution_major_version on Amazon Linux is 2018 which makes Amazon Linux use dnf even if it doesn't support it
fixes #56583

ISSUE TYPE

• Bugfix Pull Request

COMPONENT NAME

pkg_mgr.py

ADDITIONAL INFORMATION

ansible_pkg_mgr gets set incorrectly on Amazon Linux due to this commit
d53c3cd#diff-c606658e579ad7ff8b40bddb9e84e001

before change

$ ansible all -i '10.1.4.203,' --extra-vars "ansible_ssh_private_key_file=~/.ssh/djla-dev_sandbox_default.pem ansible_user=ec2-user" -m setup -a "filter=ansible_pkg_mgr"

[WARNING]: Platform linux on host 10.1.4.203 is using the discovered Python interpreter at /usr/bin/python, but future installation of
another Python interpreter could change this. See https://docs.ansible.com/ansible/2.8/reference_appendices/interpreter_discovery.html
for more information.

10.1.4.203 | SUCCESS => {
"ansible_facts": {
"ansible_pkg_mgr": "dnf",
"discovered_interpreter_python": "/usr/bin/python"
},
"changed": false
}

after change

$ ansible all -i '10.1.4.203,' --extra-vars "ansible_ssh_private_key_file=~/.ssh/djla-dev_sandbox_default.pem ansible_user=ec2-user" -m setup -a "filter=ansible_pkg_mgr"

[WARNING]: Platform linux on host 10.1.4.203 is using the discovered Python interpreter at /usr/bin/python, but future installation of
another Python interpreter could change this. See https://docs.ansible.com/ansible/2.8/reference_appendices/interpreter_discovery.html
for more information.

10.1.4.203 | SUCCESS => {
"ansible_facts": {
"ansible_pkg_mgr": "yum",
"discovered_interpreter_python": "/usr/bin/python"
},
"changed": false
}

[lpkirby]

I'm personally not a fan of parentheses around the variable in the if statement if it's not needed, but other than that, looks good to me. Thanks for the PR.

[mkrizek]

This also needs a changelog fragment, please see https://docs.ansible.com/ansible/latest/community/development_process.html#changelogs-how-to.

[ansibot]

The test ansible-test sanity --test line-endings [explain] failed with 1 error:

changelogs/fragments/56618-update-pkg_mgr.py-for-Amazon-Linux-support.yaml:0:0: use "\n" for line endings instead of "\r\n"

click here for bot help

[ansibot]

The test ansible-test sanity --test line-endings [explain] failed with 1 error:

changelogs/fragments/56618-update-pkg_mgr.py-for-Amazon-Linux-support.yaml:0:0: use "\n" for line endings instead of "\r\n"

click here for bot help

[dantech2000]

Any idea when PR will be merged?