Ansible - Moving ssh keys between two nodes

Question

Here is the problem I'm working on.

I have an ansible server I have another server M I have other servers B1, B2, B3... all known by ansible

I have a hosts file such as this

[CTRL]
M

[SLAVES]
B1
B2
B3

I want to generate a ssh key on my master (not ansible itself) and deploy it on my other slave servers to permit the master to connect on the slaves by keys.

Here is what I tried :

- hosts: CTRL
  remote_user: root
  vars_prompt:
   - name: ssh_password
     prompt : Please enter password for ssh key copy on remote nodes
     private: yes
  tasks:
   - yum: name=sshpass state=present
     sudo: yes
   - name: generate ssh key on the controller
     shell : ssh-keygen -b 2048 -t rsa -f /root/.ssh/id_rsa -q -N /dev/null
   - name: copy ssh key to the other nodes
     shell : sshpass -p '{{ ssh_password }}' ssh-copy-id root@'{{ item }}'
     with_items: groups['SLAVES']
     delegate_to: "{{ groups['CTRL'][0] }}"

The key generation works but no matter how I work I have a problem copying the key to the slave hosts

failed: [M -> M] => (item=B1) => {"changed": true, "cmd": "sshpass -p 'mypassword' ssh-copy-id root@'B1'", "delta": "0:00:00.101102", "end": "2016-07-18 11:08:56.985623", "item": "B1", "rc": 6, "start": "2016-07-18 11:08:56.884521", "warnings": []}
failed: [M -> M] => (item=B2) => {"changed": true, "cmd": "sshpass -p 'mypassword' ssh-copy-id root@'B2'", "delta": "0:00:00.101102", "end": "2016-07-18 11:08:56.985623", "item": "B1", "rc": 6, "start": "2016-07-18 11:08:56.884521", "warnings": []}
failed: [M -> M] => (item=B3) => {"changed": true, "cmd": "sshpass -p 'mypassword' ssh-copy-id root@'B3'", "delta": "0:00:00.101102", "end": "2016-07-18 11:08:56.985623", "item": "B1", "rc": 6, "start": "2016-07-18 11:08:56.884521", "warnings": []}

Do you know how I could correct my code or maybe do you have a simplier way to do what I want to do ?

Thank you.

Answer 1

This is more neat solution without file fetch:

---
- hosts: M
  tasks:
    - name: generate key pair
      shell: ssh-keygen -b 2048 -t rsa -f /root/.ssh/id_rsa -q -N /dev/null
      args:
        creates: /root/.ssh/id_rsa 

    - name: test public key
      shell: ssh-keygen -l -f /root/.ssh/id_rsa.pub
      changed_when: false

    - name: retrieve public key
      shell: cat /root/.ssh/id_rsa.pub
      register: master_public_key
      changed_when: false

- hosts: SLAVES
  tasks:
    - name: add master public key to slaves
      authorized_key:
        user: root
        key: "{{ hostvars['M'].master_public_key.stdout }}"

One of possible solutions (my first answer):

---
- hosts: M
  tasks:
    - name: generate key pair
      shell: ssh-keygen -b 2048 -t rsa -f /root/.ssh/id_rsa -q -N /dev/null

    - name: fetch public key
      fetch:
        src: /root/.ssh/id_rsa.pub
        dest: tmp/
        flat: yes

- hosts: SLAVES
  tasks:
    - name: add master public key to slaves
      authorized_key:
        user: root
        key: "{{ lookup('file', 'tmp/id_rsa.pub') }}"