Undefined 'ansible_host' in local_action hostvars

[dgoodwin]

ISSUE TYPE

• Bug Report

COMPONENT NAME

local_action

ANSIBLE VERSION

ansible 2.2.0.0
  config file = /etc/ansible/ansible.cfg
  configured module search path = Default w/o overrides

CONFIGURATION

OS / ENVIRONMENT

Seen on Fedora 25 and RHEL 7.

SUMMARY

There appears to be a problem where the ansible_host inventory variable appears unset if used within a local_action.

STEPS TO REPRODUCE

---
- name: Test Play
  hosts:  yourhostgroup
  gather_facts: no
  remote_user: root
  tasks:
  - name: Task 1
    debug: var=inventory_hostname

  - name: Task 2
    debug: var=ansible_host

  - name: Task 3
    local_action:
      module: debug
        var=ansible_host

  - name: Task 4
    local_action:
      module: debug
        var=hostvars[inventory_hostname]['ansible_host']

EXPECTED RESULTS

We expected Task 4 to output the ansible_host value of "54.158.245.48".

Per #16139 it appears that this is the recommended way to do something like wait_for in a local_action when waiting for a system to restart. Without it, there appears to be no way to access the host in situations where inventory_hostname cannot be reached from the local system running ansible.

ACTUAL RESULTS

Solution from #16139 appears to no longer work as ansible_host is not defined by default within inventory_vars. (unless you set it yourself explicitly)

PLAY [Test Play] ***************************************************************

TASK [Task 1] ******************************************************************
ok: [ded-int-aws-master-dbea1] => {
    "inventory_hostname": "ded-int-aws-master-dbea1"
}
ok: [ded-int-aws-master-4b25f] => {
    "inventory_hostname": "ded-int-aws-master-4b25f"
}
ok: [ded-int-aws-master-9938e] => {
    "inventory_hostname": "ded-int-aws-master-9938e"
}

TASK [Task 2] ******************************************************************
ok: [ded-int-aws-master-dbea1] => {
    "ansible_host": "54.158.245.48"
}
ok: [ded-int-aws-master-4b25f] => {
    "ansible_host": "54.227.231.254"
}
ok: [ded-int-aws-master-9938e] => {
    "ansible_host": "54.242.207.100"
}

TASK [Task 3] ******************************************************************
ok: [ded-int-aws-master-dbea1 -> localhost] => {
    "ansible_host": "localhost"
}
ok: [ded-int-aws-master-4b25f -> localhost] => {
    "ansible_host": "localhost"
}
ok: [ded-int-aws-master-9938e -> localhost] => {
    "ansible_host": "localhost"
}

TASK [Task 4] ******************************************************************
ok: [ded-int-aws-master-dbea1 -> localhost] => {
    "hostvars[inventory_hostname]['ansible_host']": "VARIABLE IS NOT DEFINED!"
}
ok: [ded-int-aws-master-4b25f -> localhost] => {
    "hostvars[inventory_hostname]['ansible_host']": "VARIABLE IS NOT DEFINED!"
}
ok: [ded-int-aws-master-9938e -> localhost] => {
    "hostvars[inventory_hostname]['ansible_host']": "VARIABLE IS NOT DEFINED!"
}

PLAY RECAP *********************************************************************
ded-int-aws-master-4b25f   : ok=4    changed=0    unreachable=0    failed=0   
ded-int-aws-master-9938e   : ok=4    changed=0    unreachable=0    failed=0   
ded-int-aws-master-dbea1   : ok=4    changed=0    unreachable=0    failed=0   

We did find a simple workaround just using a set_fact to assign some variable to the value of ansible_host, then using it within the local_action.

[bcoca]

ansible_host is set after an attempted connection, which you don't.

Also debug in any case ignores connections as it runs 'in memory' on the controller at all times, using local_action is irrelevant for this type of module.

Can you show any other case in which this is an issue that does not match the above?

[dgoodwin]

The bug surfaced when trying to wait for a host to reboot with a task like this:

  - name: Wait for master to restart
    local_action:
      module: wait_for
        host="{{ hostvars[inventory_hostname]['ansible_host'] }}"
        port="{{ ansible_port | default(22,boolean=True) }}"
        delay=10
        state=started
        timeout=600
    become: no

This appeared to be best option in environments where inventory_hostname is not necessarily reachable (which ours is), as described in workaround for #16139. debug was just our attempt to replicate as simply as possible.

[bcoca]

well, this wouldn't work for the same reason, ansible_host would correspond to localhost as you delegate_to it, use connection: local instead, but that will only preserve the connection info from the original host, if the variable was not set for it, it still won't appear.

[dgoodwin]

Sorry @bcoca I am confused.

We picked up this example from #16139, it appeared that going to hostvars[inventory_hostname]['ansible_host'] might work, given that inventory_hostname would still point to the remote system we're waiting for. Are you saying it's expected for ansible_host to not be defined in that context?

I do notice that:

  - name: Task 2
    debug: var=ansible_host
  - name: Task 5
    debug: var=hostvars[inventory_hostname]['ansible_host']

Task 2 will show the host, task 5 will not, which confused us.

If this is not a bug and there is not expected to be any way to access the remote IP if inventory_hostname isn't reachable feel free to close, we have the set_fact workaround it just felt like this might be a bug.

[bcoca]

it would be a bug if you defined ansible_host in inventory and it is not appearing when you reference it, it is not a bug if you are expecting the return of the connection to define it.

[dgoodwin]

I understand, thanks @bcoca .

CC @mwoodson @detiber