use container_file_read in playbook

roles/lxc_guest/tasks/main.yaml

@@ -63,6 +63,12 @@
   ignore_errors: true
   changed_when: "cert_key_existance.rc != 0"
 - block:
+    - name: Read host public key
+      container_file_read:
+        name: "{{ vm_name }}"
+        path: "/etc/ssh/ssh_host_ed25519_key.pub"
+      register: vm_public_key
+
     - name: get pub key
       shell: lxc-attach -n {{ vm_name }} --clear-env -e -- bash -c "cat /etc/ssh/ssh_host_ed25519_key.pub"
       register: pub_key