day-07

SETUP MODULE: used to print complete info of nodes
ansible all -m setup
ansible all -m setup | grep -i family
ansible all -m setup | grep -i cpu
ansible all -m setup | grep -i mem
ansible all -m setup | grep -i pkg


CONDITIONS:
CLUSTER: Group of servers
HOMOGENIUS: all servers have having same OS and flavour.
HETROGENIUS: all servers have different OS and flavour.

used to execute this module when we have different Clusters.

RedHat=yum
Ubuntu=apt

- hosts: all
  tasks:
    - name: installing git on RedHat
      yum: name=git state=present
      when: ansible_os_family == "RedHat"
    - name: installing git on Debian
      apt: name=git state=present
      when: ansible_os_family == "Debian"


sed -i 's/present/absent/g' playbbok.yml

- hosts: all
  tasks:
    - name: installing git on RedHat
      yum: name=git state=absent
      when: ansible_os_family == "RedHat"
    - name: installing git on Ubuntu
      apt: name=git state=absent
      when: ansible_os_family == "Ubuntu"


ROLES:
roles is a way of organizing playbooks in a structured format.
main purpose of roles is to encapsulate the data.
we can reuse the roles multiple times.
length of the playbook is decreased.
it contains on vars, templates, task -----
in real time we use roles for our daily activities.

mkdir playbooks
cd playbooks/

mkdir -p roles/pkgs/tasks
vim roles/pkgs/tasks/main.yml

- name: installing pkgs
  yum: name=git state=present
- name: install maven
  yum: name=maven state=present
- name: installing httpd
  yum: name=httpd state=present

mkdir -p roles/users/tasks
vim roles/users/tasks/main.yml

- name: create users
  user: name={{item}} state=present
  with_items:
    - uday
    - naveen
    - rohit
    - lokesh
    - saipallavi
    - supriya

mkdir -p roles/dep/tasks
vim roles/dep/tasks/main.yml

- name: deploymemnt
  debug:
    msg: "my code is deployed"

.
├── master.yml
└── roles
    ├── dep
    │   └── tasks
    │       └── main.yml
    ├── pkgs
    │   └── tasks
    │       └── main.yml
    └── users
        └── tasks
            └── main.yml

vim master.yml
- hosts: all
  roles:
    - dep
    - user
    - pkgs


- hosts: all
  tasks:
    - name: to pring mgs
      debug:
        msg: "the node name os: {{ansible_hostname}}, the total mem is:
          {{ansible_memtotal_mb}}, free mem is {{ansible_memfree_mb}}, the
          flavour of ec2 is: {{ansible_os_family}}, total cpus is:
            {{ansible_processor_vcpus}}"

- hosts: all
  vars:
    size_total: 8
  tasks:
    - name: to pring mgs
      debug:
        msg: "the node name os: {{ansible_hostname}}, the total mem is:
          {{ansible_memtotal_mb}}, free mem is {{ansible_memfree_mb}}, the
          flavour of ec2 is: {{ansible_os_family}}, totol cpus is:
            {{ansible_processor_vcpus}}, the blokc size: {{size_total}}"


JINJA2 TEMPLATE: used to get the customized op, here its a text file which can extract the variables and these values will change as per time.

LOOKUPS: this module used to get data from files, db and key values

- hosts: dev
  vars:
    a: "{{lookup('file', '/root/creds.txt') }}"
  tasks:
    - debug:
        msg: "hai my user name is {{a}}"

cat creds.txt
user=raham