How to use hostvars in vagrant env - ansible

Question

I'm having trouble using hostvars to pass a variable to another host in a vagrant environment, the code I did:
Vagrant.configure("2") do |config|
config.vm.define "server_1" do |server_1|
server_1.vm.hostname = "n1"
server_1.vm.box = "centos/7"
server_1.vm.network "public_network", bridge: "wlp1s0", ip: "192.168.0.50"
end
config.vm.define "worker_1" do |worker_1|
worker_1.vm.hostname = "n2"
worker_1.vm.box = "centos/7"
worker_1.vm.network "public_network", bridge: "wlp1s0", ip: "192.168.0.51"
end
config.vm.provider "virtualbox" do |vb|
vb.memory = 1024
end
config.vm.provision "ansible" do |ansible|
ansible.playbook = "t0a.yml"
end
end
t0a.yml
---
- hosts: server*
tasks:
- set_fact: hello=world
- hosts: worker*
tasks:
- debug:
msg: "{{ hostvars['server_1']['hello'] }}"
expected:
TASK [show] *******************************************************************
ok: [worker_1] => {
"msg": [
"works"
]
}
actual:
TASK [debug] ********************************************************************
fatal: [worker_1]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'ansible.vars.hostvars.HostVarsVars object' has no attribute 'hello'\n\nThe error appears to have been in '/home/kayke/Documentos/vm-vagrant/provision-ansible/centos/t0_tests/t0a.yml': line 8, column 5, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n tasks:\n - debug:\n ^ here\n"}

Answer 1

What you want is a single playbook that targets both server and worker, matching on their host patterns, because that way there is only a single ansible run, versus what's happening now is that ansible is being run twice, once for each host. Thus:
- hosts: server*
tasks:
- set_fact: hello=world
- hosts: worker*
tasks:
- debug:
msg: "{{ hostvars["server_1"]["hello"] }}"
and invoked at the very end, like you see here: https://github.com/kubernetes-sigs/kubespray/blob/v2.8.3/Vagrantfile#L177-L193
I haven't studied Vagrant enough to know if it will write out an inventory file for you, or what, but if you need an example kubespray is also generating an inventory file from all the known vms, too: https://github.com/kubernetes-sigs/kubespray/blob/v2.8.3/Vagrantfile#L69-L75
If you don't like that approach, you can also use fact caching plugins to cause ansible to write out the fact cache for the hosts in a way that the worker playbooks can read in, but as you might suspect, that's a ton more work.