Ansible: Provided hosts list is empty

Question

I have this below playbook where the remote host is an user input and subsequently I am trying to gather facts about the remote host and copy the same to a file in local:

---
- hosts: localhost
  vars_prompt:
      name: hostname
      prompt: "Enter Hostname"
  tasks:
    - name: Add hosts to known_hosts file
      add_host: name={{ hostname }} groups=new
    - name: Check if Host is reachable
      shell: ansible -m ping {{ hostname }}
    - name: Remove existing remote hosts
      shell: ssh-keygen -R {{ hostname }}
    - name: Setup passwordless SSH login
      shell: ssh-copy-id -i ~/.ssh/id_rsa user@{{ hostname }}
    - name: Display facts
      command: ansible {{ groups['new'] }} -m setup
      register: output
    - copy: content="{{ output }}" dest=/var/tmp/dir/Node_Health/temp
...

I get the below error in the temp file:

Node_Health]# cat temp
{"start": "2016-06-17 09:26:59.174155", "delta": "0:00:00.279268", "cmd": ["ansible", "[udl360x4675]", "-m", "setup"], "end": "2016-06-17 09:26:59.453423", "stderr": " [WARNING]: provided hosts list is empty, only localhost is available", "stdout": "", "stdout_lines": [], "changed": true, "rc": 0, "warnings":

I also tried the below playbook which also gives the same error:

---
 - hosts: localhost
  vars_prompt:
      name: hostname
      prompt: "Enter Hostname"
  tasks:
    - name: Add hosts to known_hosts file
      add_host: name={{ hostname }} groups=new
    - name: Check if Host is reachable
      shell: ansible -m ping {{ hostname }}
    - name: Remove existing remote hosts
      shell: ssh-keygen -R {{ hostname }}
    - name: Setup passwordless SSH login
      shell: ssh-copy-id -i ~/.ssh/id_rsa user@{{ hostname }}
- hosts: new
   tasks:
    - name: Display facts
      command: ansible {{ groups['new'] }} -m setup
      register: output
    - local_action: copy content="{{ output }}" dest=/var/tmp/dir/Node_Health/temp
...

Any help will be appreciated.

Answer 1

Ansible assumes that you have all your hosts in an inventory file somewhere.

add_host only adds your host to the currently running Ansible, and that doesn't propagate to the copy of Ansible you call.

You're going to have to either:

• change the command to use an inline inventory list, like ansible all -i '{{ hostname }},' -m setup (More details re the use of -i '<hostname>,' here

• or write out the hostname to a file, and use that as your inventory file

Answer 2

Put your hosts in a hosts.ini file, with the following syntax:

[nodes]
node_u1 ansible_user=root   ansible_host=127.0.0.1
node_u2 ansible_user=root   ansible_host=127.0.1.1
node_u3 ansible_user=root   ansible_host=127.0.2.1
node_u4 ansible_user=root   ansible_host=127.0.3.1
node_u5 ansible_user=root   ansible_host=127.0.4.1

Running ansible, use: ansible-playbook -i hosts.ini

You can also save your hosts file in /etc/ansible/hosts to avoid passing hosts as parameters. Ansible looks there as a default location. Then just run using:

ansible-playbook <playbook.yml>

Answer 3

For me it looks that thay don't know where the inventory file is located.

I used cmd:
ansible-playbook name.yml -i hostfile