How to wait for ssh to become available on a host before installing a role? - ansible

Question

Is there a way to wait for ssh to become available on a host before installing a role? There's wait_for_connection but I only figured out how to use it with tasks.
This particular playbook spin up servers on a cloud provider before attempting to install roles. But fails since the ssh service on the hosts isn't available yet.
How should I fix this?
---
- hosts: localhost
connection: local
tasks:
- name: Deploy vultr servers
include_tasks: create_vultr_server.yml
loop: "{{ groups['vultr_servers'] }}"
- hosts: all
gather_facts: no
become: true
tasks:
- name: wait_for_connection # This one works
wait_for_connection:
delay: 5
timeout: 600
- name: Gather facts for first time
setup:
- name: Install curl
package:
name: "curl"
state: present
roles: # How to NOT install roles UNLESS the current host is available ?
- role: apache2
vars:
doc_root: /var/www/example
message: 'Hello world!'
- common-tools

Answer 1

Ansible play actions start with pre_tasks, then roles, followed by tasks and finally post_tasks. Move your wait_for_connection task as the first pre_tasks and it will block everything until connection is available:
- hosts: all
gather_facts: no
become: true
pre_tasks:
- name: wait_for_connection # This one works
wait_for_connection:
delay: 5
timeout: 600
roles: ...
tasks: ...
For more info on execution order, see this title in role's documentation (paragraph just above the notes).
Note: you probably want to move all your current example tasks in that section too so that facts are gathered and curl installed prior to do anything else.