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from __future__ import (absolute_import, division, print_function)
__metaclass__ = type
DOCUMENTATION = """
name: pg_sr_cluster_nodes
author: Julien Tachoires
short_description: Lookup Postgres SR cluster nodes
description:
- "Retrieves the Postgres streaming replication nodes list, based on
node's private IP"
options:
_terms:
description: The private IP of one member of the SR cluster.
required: False
default:
description: The private IP of the current node is used.
"""
EXAMPLES = """
- name: Show all members of the SR cluster that the current node is part of
debug: msg="{{ lookup('pg_sr_cluster_nodes') }}"
- name: Show all members of the SR cluster that the {{ primary_private_ip }} is part of
debug: msg="{{ lookup('pg_sr_cluster_nodes', primary_private_ip) }}"
"""
RETURN = """
_value:
description:
- List of Postgres nodes
type: list
elements: dict
"""
from ansible.errors import AnsibleError
from ansible.plugins.lookup import LookupBase
class LookupModule(LookupBase):
def run(self, terms, variables=None, **kwargs):
pg_clusters = {}
pg_standbys = {}
pg_primary_map = {}
myvars = getattr(self._templar, '_available_variables', {})
# If no terms, we'll used the current private IP
if len(terms) == 0:
node_private_ip = myvars['hostvars'][variables['inventory_hostname']]['private_ip']
else:
node_private_ip = terms[0]
# If no primary found in the inventory we return an empty list
if 'primary' not in variables['groups']:
return []
# Initiate pg_clusters and pg_primary_map for each primary node we have
# in the inventory.
for host in variables['groups']['primary']:
hostvars = myvars['hostvars'][host]
private_ip = hostvars['private_ip']
pg_clusters[private_ip] = []
pg_clusters[private_ip].append(
dict(
node_type='primary',
ansible_host=hostvars['ansible_host'],
hostname=hostvars.get('hostname',
hostvars.get('ansible_hostname')),
private_ip=hostvars['private_ip'],
upstream_node_private_ip=None,
replication_type=None,
inventory_hostname=hostvars['inventory_hostname']
)
)
pg_primary_map[private_ip] = private_ip
# Populate pg_standbys dict if we have standby nodes in the inventory
if 'standby' in variables['groups']:
for host in variables['groups']['standby']:
hostvars = myvars['hostvars'][host]
pg_standbys[host] = dict(
node_type='standby',
ansible_host=hostvars['ansible_host'],
hostname=hostvars.get('hostname',
hostvars.get('ansible_hostname')),
private_ip=hostvars['private_ip'],
upstream_node_private_ip=hostvars['upstream_node_private_ip'],
replication_type=hostvars.get('replication_type',
'asynchronous'),
inventory_hostname=hostvars['inventory_hostname']
)
pg_standbys_len = len(pg_standbys.keys())
# Append the standby nodes into the right pg_clusters item, based on
# standby's upstream node.
while pg_standbys_len != 0:
for k in list(pg_standbys.keys()):
sby = pg_standbys[k]
if sby['upstream_node_private_ip'] in pg_primary_map:
upstream_private_ip = sby['upstream_node_private_ip']
primary_private_ip = pg_primary_map[upstream_private_ip]
pg_primary_map[sby['private_ip']] = primary_private_ip
pg_clusters[primary_private_ip].append(sby)
del(pg_standbys[k])
# Case when at least one host has not been handled in this loop
# iteration.
if pg_standbys_len == len(pg_standbys.keys()):
raise AnsibleError(
"Inventory error with the following standbys nodes %s. "
"Upstream node is not configured or not found"
% [s for s in pg_standbys.keys()]
)
pg_standbys_len = len(pg_standbys.keys())
if node_private_ip in pg_primary_map:
# Current node is part of one of the SR clusters found
return pg_clusters[pg_primary_map[node_private_ip]]
else:
primary_private_ips = list(pg_clusters.keys())
# If the current node is not part of any SR cluster found, but,
# only one SR cluster has been found, then we return this SR
# cluster because there is no doubt.
if len(primary_private_ips) == 1:
return pg_clusters[primary_private_ips[0]]
else:
raise AnsibleError(
"Unable to find the SR cluster topology because multiple "
"SR clusters were found and this current node does not "
"appear to be part of any of them"
)
|
