Ansible Setup and Usage

Initially

add hosts to ~/.ssh/config this allows you to specify everything you need to either ssh or use tools like Ansible. Then in /etc/ansible/hosts specify the same shorthand name you used in the ssh config file.

After setup in both places, run a ping using the Ansible ping module: ansible -m ping all {in place of all, you can specify the group used in the ansible hosts file.}

germany | FAILED! => {
    "changed": false,
    "module_stderr": "Shared connection to x.x.x.x closed.\r\n",
    "module_stdout": "/bin/sh: 1: /usr/bin/python: not found\r\n",
    "msg": "MODULE FAILURE\nSee stdout/stderr for the exact error",
    "rc": 127
}

to fix, ssh -> install python2 / python2-minimal

$ ssh germany
user@germany ~ # apt update -y ; apt install python -y
{apt installs python2}
user@germany ~ # exit

$ ansible -m ping all
lax | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
kc | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
buf | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
aws | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
nor | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
au | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
germany | SUCCESS => {
    "changed": false,
    "ping": "pong"
}

Installing fail2ban and starting with os [ubuntu]

# pi @ pi4-1tb in ~/projects/ansible on git:master x [13:07:37] 
$ cat apt-update.yml 
--- # Fail2ban
- hosts: all
  become: yes
  tasks:
  - name: Update Ubuntu cache
    apt:
      update_cache: yes
      force_apt_get: True
  - name: Update Ubuntu packages
    apt:
      name: "*"
      state: latest
      force_apt_get: True
  - name: Apt autoremove
    apt:
      autoremove: yes
      force_apt_get: True
  - name: install essentials
    apt:
      name: 
        - htop
        - fail2ban
        - git
        - curl
        - sshfs
        - unzip
        - tar
  - name: enable fail2ban at boot
    service:
      name: fail2ban
      enabled: yes

Error with RHEL

$ ansible vm -m ping
git | FAILED! => {
    "changed": false,
    "module_stderr": "Shared connection to 192.168.11.15 closed.\r\n",
    "module_stdout": "/bin/sh: /usr/bin/python2: No such file or directory\r\n",
    "msg": "The module failed to execute correctly, you probably need to set the interpreter.\nSee stdout/stderr for the exact error",
    "rc": 127
}

Waht the problem is? One of two things. Python is not installed - in that case, ssh@host & sudo yum install python2 -y OR add a vars to your /etc/ansible/hosts file:

[vm:vars]
ansible_python_interpreter=/usr/bin/python2

Now it works:

$ ansible vm -m ping
dns | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
factorio | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
docker | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
git | SUCCESS => {
    "changed": false,
    "ping": "pong"
}