draft for checking host certificate task

library/container_certificate_exists.py

@@ -0,0 +1,62 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+DOCUMENTATION = '''
+---
+module: container_certificate_exists
+author: Edoardo Putti
+short_description: Return wheter a certificate is present in the container
+description:
+    - Look for the /etc/ssh/ssh_host_ed25519_key-cert.pub file
+options:
+    name:
+        required: true
+        description:
+            - Name of the container
+'''
+
+from ansible.module_utils.basic import *
+
+
+def main():
+    module = AnsibleModule(
+            argument_spec = dict(
+                name = dict(
+                    required = True,
+                    type = 'str',
+                    ),
+            ),
+            supports_check_mode=True
+    )
+    
+    try:
+        import lxc
+    except ImportError:
+        self.module.fail_json(
+                changed= False,
+                msg= 'Error importing lxc, is python-lxc installed?',
+                )
+
+    container_name = module.params.get('name')
+
+    result = {}
+    result['name'] = container_name
+
+    if container_name in lxc.list_containers():
+
+        container_certificate = container.attach_wait(
+                lxc.attach_run_command,
+                ['cat', '/etc/ssh/ssh_host_ed25519_key-cert.pub',],
+                )
+        result['changed'] = True
+        result['msg'] = container_certificate
+        
+    else:
+        result['changed'] = False
+        result['failure'] = True
+        result['msg'] = "Target container does not exists"
+
+    module.exit_json(**result)
+
+if __name__ == '__main__':
+    main()

roles/lxc_guest/tasks/main.yaml

@@ -50,6 +50,11 @@
   register: container_dns_configuration
   changed_when: "container_dns_configuration.stdout != 'nameserver {{ hostvars[ext_gateway].ansible_host }}'"
 
+
+- name: Check if host certificate exists
+  container_certificate_exists:
+    name: "{{ vm_name }}"
+
 - name: check if cert key exist
   shell: lxc-attach -n {{ vm_name }} --clear-env -e -- bash -c "ls /etc/ssh/ssh_host_ed25519_key-cert.pub"
   register: cert_key_existance