Ansible - List of Linux security updates needed on remote servers - linux

Question

I wanted to run a playbook that will accurately report if one of the remote servers requires security updates. Ansible server = Centos 7, remote servers Amazon Linux.
Remote server would highlight on startup something like below:
https://aws.amazon.com/amazon-linux-2/
8 package(s) needed for security, out of 46 available
Run "sudo yum update" to apply all updates.
To confirm this, I put a playbook together, cobbled from many sources (below) that does perform that function to a degree. It does suggest whether the remote server requires security updates but doesn't say what these updates are?
- name: check if security updates are needed
hosts: elk
tasks:
- name: check yum security updates
shell: "yum updateinfo list all security"
changed_when: false
register: security_update
- debug: msg="Security update required"
when: security_update.stdout != "0"
- name: list some packages
yum: list=available
Then, when I run my updates install playbook:
- hosts: elk
remote_user: ansadm
become: yes
become_method: sudo
tasks:
- name: Move repos from backup to yum.repos.d
shell: mv -f /backup/* /etc/yum.repos.d/
register: shell_result
failed_when: '"No such file or directory" in shell_result.stderr_lines'
- name: Remove redhat.repo
shell: rm -f /etc/yum.repos.d/redhat.repo
register: shell_result
failed_when: '"No such file or directory" in shell_result.stderr_lines'
- name: add line to yum.conf
lineinfile:
dest: /etc/yum.conf
line: exclude=kernel* redhat-release*
state: present
create: yes
- name: yum clean
shell: yum make-cache
register: shell_result
failed_when: '"There are no enabled repos" in shell_result.stderr_lines'
- name: install all security patches
yum:
name: '*'
state: latest
security: yes
bugfix: yes
skip_broken: yes
After install, you would get something similar to below (btw - these are outputs from different servers)
https://aws.amazon.com/amazon-linux-2/
No packages needed for security; 37 packages available
Run "sudo yum update" to apply all updates.
But if I run my list security updates playbook again - it gives a false positive as it still reports security updates needed?
PLAY [check if security updates are needed] ************************************
TASK [Gathering Facts] *********************************************************
ok: [10.10.10.192]
TASK [check yum security updates] **********************************************
ok: [10.10.10.192]
TASK [debug] *******************************************************************
ok: [10.10.10.192] => {
"msg": "Security update required"
}
TASK [list some packages] ******************************************************
ok: [10.10.10.192]
PLAY RECAP *********************************************************************
10.10.10.192 : ok=4 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
[ansadm#ansible playbooks]$
What do I need to omit/include in playbook to reflect the changes after the install of the updates?
Thanks in advance :)

Answer 1

So I ran your yum command locally on my system I get the following.
45) local-user#server:/home/local-user> yum updateinfo list all security
Loaded plugins: ulninfo
local_repo | 2.9 kB 00:00:00
updateinfo list done
Now granted our systems may have different output here, but it will serve the purpose of my explanation. The output of the entire command is saved to your register, but your when conditional says to run when the output of that command is not EXACTLY "0".
So unless you par that response down with some awk's or sed's, and it responds with any more text that literally just the character "0" that debug task is always going to fire off.