host_groups

Synopsis

Provide a list of group of hosts.

Attributes

Each item of the list has the following attributes:

Name	req?	Description
name	yes	The name of the host group
hosts	no	A list of hosts included in this group. Each host must be defined in the hosts: part (Or the associated Ansible inventory).
groups	no	A list of host_group from wich all hosts will be included in this group. Allow group composition, and also group renaming.
force_setup	no	A common Ansible problem is when referencing host info for a host which has not being accessed, so there is no fact grabbed for it. Setting this flag to yes will trigger an access to all hosts of this group at the begining of the play. Default: no
when	no	Boolean. Allow conditional deployment of this item. Default True

Note than same host can belong to several groups.

Example

host_groups:
- name: data_nodes
  hosts:    # This host list in standard YAML style
  - dn1
  - dn2
  - dn3

- name: control_nodes
  hosts: [ "sr", "en", "nn1", "nn2" ]   # And these in YAML 'flow style

- name: empty_group

# Group renaming
- name: brokers
  groups:
  - kafka_brokers

Tricks

If, when running HADeploy you encounter error like:

fatal: [dn1]: FAILED! => {"changed": false, "failed": true, "msg": "AnsibleUndefinedVariable: 'dict object' has no attribute 'ansible_fqdn'"}

it is most likely that you need to set force_setup on some host_group or host.