Note_Tech

All technological notes.

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Ansible - Inventory

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• Ansible - Inventory
  • Inventory
    • Inventory Files
    • Parent and Child relationship
      • yaml file

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Inventory

• inventory

  • a file or directory that defines the hosts (servers, devices, etc.) that Ansible manages, and how they are organized into groups.
  • enable agentless connections.

• Connections can be built:

  • Linux: SSH
  • Windows: Powershell Remoting

• It defines:

  • Hosts: individual systems (by name or IP).
  • Groups: logical collections of hosts (e.g., webservers, dbservers).
  • Variables: connection details, credentials, or custom settings per host/group.

• Ansible parameter for connection

  • ansible_host=server1.company.com: specify the FQDN or IP address of a server.
  • ansible_connection=ssh/vinrm/localhost: specify the connection
  • ansible_port=22: specify the connection port
  • ansible_user=root: specify the connection user
  • ansible_ssh_pass=pwd: specify the connection password

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Inventory Files

• Default inventory file

  • /etc/ansible/hosts

• Group by:

  • [GROUP_NAME]

• Can be in INI or YAML format.

Parent and Child relationship

• common configuration can be applied to parent group level

• specific configuration can be applied to children group level

• Parent and child semantic

• ini file

[webservers:children]
webservers_us
webservers_eu

[webservers_us]
server1_us.com ansible_host=192.168.8.101
server2_us.com ansible_host=192.168.8.102

[webservers_eu]
server1_eu.com ansible_host=10.12.0.101
server2_eu.com ansible_host=10.12.0.102

• yaml file

all:
  children:
    webservers:
      children:
        webservers_us:
          hosts:
            server1_us.com:
              ansible_host: 192.168.8.101
            server2_us.com:
              ansible_host: 192.168.8.102
        webservers_eu:
          hosts:
            server1_eu.com:
              ansible_host: 10.12.0.101
            server2_eu.com:
              ansible_host: 10.12.0.102

---

#### `ini` file

```ini
[webservers]
web1 ansible_host=192.168.1.10 ansible_user=ubuntu
web2 ansible_host=192.168.1.11 ansible_user=ubuntu

[dbservers]
db1 ansible_host=192.168.1.20 ansible_user=postgres

---

• Example:
  • using alias and parameters

# define hosts

# define a alias, host, connection method, and password
web ansible_host=server1.company.com ansible_connection=ssh ansible_user=root
db ansible_host=server2.company.com ansible_connection=winrm ansible_user=admin ansible_password=P@#
mail ansible_host=server3.company.com ansible_connection=ssh ansible_ssh_pass=P@#
web2 ansible_host=server4.company.com ansible_connection=winrm

# define connection with localhost
localhost ansible_connection=localhost

# grouping
[webservers]
web
web2
localhost

[dbservers]
db

# group of group
[all_servers:children]
webservers
dbservers

---

yaml file

• can be used for complex structures

all:
  children:
    webservers:
      hosts:
        web1.example.com:
        web2.example.com:
    dbservers:
      hosts:
        db1.example.com:
        db2.example.com: