update_ssh_host_key.yml

update_ssh_host_key.yml

- hosts: all
  gather_facts: false
  become: yes
  vars:
    target_host: target.host.enterprise.com
    target_user: /home/targetuser/.ssh/known_hosts
    separator: /
    


  tasks:

    #Run SSH-keygen and remove entries that use a FQDN or shortname
    #Old file with be saved in {{ target_user }}/known_hosts.old
  - name: "Run ssh-keygen and remove {{ target_host }}"
    shell: |
      ssh-keygen -R {{ target_host }} -f {{ target_user }}
      ssh-keygen -R {{ target_host.split(".")[0] | lower }} -f {{ target_user }}
      
    #Runs ssh-keyscan and adds host entry with the following formatting: xxx.xx.xxx.com,192.168.0.5 ssh-rsa [key]
  - name: "Run ssh-keyscan and add {{ target_host }}"
    shell: ssh-keyscan {{ target_host }} >> {{ target_user }}

    #Since we have to use become to change this, it will change the permissions to root. This will revert back to previous permissions. Separator variable must be used because there is forward and backslash are 
    #hard to use for a split function without escaping them in weird ways.

  - name: Fix ownership of known_hosts for "{{ target_user }}"
    file:
      path: "{{ target_user }}"
      owner: "{{ target_user.split(separator)[2] | lower }}"
      group: "{{ target_user.split(separator)[2] | lower }}"