how to create Ansible playbook to obtain OS versions of the remote hosts? - linux

Question

I'm new to ansible. I have a requirement that requires me to pull OS version for of more than 450 linux severs hosted in AWS. AWS does not provide this feature - it rather suggests us to get it from puppet or chef.
I created few simple playbooks which does not run
---
- hosts: testmachine
user: ec2-user
sudo: yes
tasks:
- name: Update all packages to latest
yum: name=* state=latest
task:
- name: obtain OS version
shell: Redhat-release
playbook should output a text file with hostname and OS version. Any insight on this will be highly appreciated.

Answer 1

Use one of the following Jinja2 expressions:
{{ hostvars[inventory_hostname].ansible_distribution }}
{{ hostvars[inventory_hostname].ansible_distribution_major_version }}
{{ hostvars[inventory_hostname].ansible_distribution_version }}
where:
hostvars and ansible_... are built-in and automatically collected by Ansible
ansible_distribution is the host being processed by Ansible
For example, assuming you are running the Ansible role test_role against the host host.example.com running a CentOS 7 distribution:
---
- debug:
msg: "{{ hostvars[inventory_hostname].ansible_distribution }}"
- debug:
msg: "{{ hostvars[inventory_hostname].ansible_distribution_major_version }}"
- debug:
msg: "{{ hostvars[inventory_hostname].ansible_distribution_version }}"
will give you:
TASK [test_role : debug] *******************************************************
ok: [host.example.com] => {
"msg": "CentOS"
}
TASK [test_role : debug] *******************************************************
ok: [host.example.com] => {
"msg": "7"
}
TASK [test_role : debug] *******************************************************
ok: [host.example.com] => {
"msg": "7.5.1804"
}

Answer 2

In a structured way:
- hosts: all
become: no
vars:
output_file: os.csv
tasks:
- block:
# For permisison setup.
- name: get current user
command: whoami
register: whoami
run_once: yes
- name: clean file
copy:
dest: "{{ output_file }}"
content: 'hostname,distribution,version,release'
owner: "{{ whoami.stdout }}"
run_once: yes
- name: fill os information
lineinfile:
path: "{{ output_file }}"
line: "{{ ansible_hostname }},\
{{ ansible_distribution }},\
{{ ansible_distribution_version }},\
{{ ansible_distribution_release }}"
# Tries to prevent concurrent writes.
throttle: 1
delegate_to: localhost
Creates a comma separated file named os.csv in execution folder. You can use any variables you want editing line:.

Answer 3

Ansible already provides a lot of information about the remote host in the "hostvars" variable that is automatically available.
To see information of your host named "my_remote_box_name", e.g. do
- debug: var=hostvars['my_remote_box_name']
Some OS information is in
hostvars['my_remote_box_name']['ansible_lsb']
Which, for one of my ubuntu hosts would be along:
{
"hostvars['my_remote_box_name']['ansible_lsb']": {
"codename": "xenial",
"description": "Ubuntu 16.04.1 LTS",
"id": "Ubuntu",
"major_release": "16",
"release": "16.04"
}
You can just use those variables in your playbooks and templates, using the "{{ variable_name }}" notation.
- debug: msg="My release is {{ansible_lsb.release}}"
output:
"msg": "My release is 16.04"

Answer 4

For a couple of windows instances:
- debug:
msg:
- "ansible_distribution {{ hostvars[inventory_hostname].ansible_distribution }}"
- "major version {{ hostvars[inventory_hostname].ansible_distribution_major_version }}"
- "version {{ hostvars[inventory_hostname].ansible_distribution_version }}"
gives:
ok: [server1] => {
"msg": [
"ansible_distribution Microsoft Windows Server 2008 R2 Standard ",
"major version 6",
"version 6.1.7601.65536"
]
}
ok: [server2] => {
"msg": [
"ansible_distribution Microsoft Windows Server 2016 Standard",
"major version 10",
"version 10.0.14393.0"
]
}

Answer 5

"AWS does not provide this feature " - you can check file /etc/os-release to get details of aws instance.
For example
[ec2-user#ip-xx-xx-xx ~]$ cat /etc/os-release
NAME="Amazon Linux AMI"
VERSION="2016.03"
ID="amzn"
ID_LIKE="rhel fedora"
VERSION_ID="2016.03"
PRETTY_NAME="Amazon Linux AMI 2016.03"
ANSI_COLOR="0;33"
CPE_NAME="cpe:/o:amazon:linux:2016.03:ga"
HOME_URL="http://aws.amazon.com/amazon-linux-ami/"

Answer 6

- name: obtain OS version
shell: Redhat-release
register: result
- name: print OS version
debug: var=result.stdout