Charmed-Kubernetes/etcd/lib/etcd_databag.py

124 lines
4.5 KiB
Python

from charms import layer
from charmhelpers.core.hookenv import unit_get
from charmhelpers.core.hookenv import config
from charmhelpers.core.hookenv import is_leader
from charmhelpers.core.hookenv import leader_get, leader_set
from charmhelpers.core import unitdata
from charms.reactive import is_state
from etcd_lib import get_ingress_address
from etcd_lib import get_bind_address
import string
import random
import os
class EtcdDatabag:
'''
This class represents a configuration object to ease configuration of an
etcd unit during deployment and reconfiguration. The full dict of data
when expanded looks like the following:
{'public_address': '127.0.0.1',
'cluster_bind_address': '127.0.0.1',
'db_bind_address': '127.0.0.1',
'cluster_address': '127.0.0.1',
'db_address': '127.0.0.1',
'unit_name': 'etcd0',
'port': '2380',
'management_port': '2379',
'ca_certificate': '/etc/ssl/etcd/ca.crt',
'server_certificate': '/etc/ssl/etcd/server.crt',
'server_key': '/etc/ssl/etcd/server.key',
'token': '8XG27B',
'cluster_state': 'existing'}
'''
def __init__(self):
self.db = unitdata.kv()
self.cluster_bind_address = self.get_bind_address('cluster')
self.db_bind_address = self.get_bind_address('db')
self.port = config('port')
self.management_port = config('management_port')
# Live polled properties
self.public_address = unit_get('public-address')
self.cluster_address = get_ingress_address('cluster')
self.db_address = get_ingress_address('db')
self.unit_name = os.getenv('JUJU_UNIT_NAME').replace('/', '')
# Pull the TLS certificate paths from layer data
tls_opts = layer.options('tls-client')
ca_path = tls_opts['ca_certificate_path']
crt_path = tls_opts['server_certificate_path']
key_path = tls_opts['server_key_path']
# Pull the static etcd configuration from layer-data
etcd_opts = layer.options('etcd')
self.etcd_conf_dir = etcd_opts['etcd_conf_dir']
# This getter determines the current context of the storage path
# depending on if durable storage is mounted.
self.etcd_data_dir = self.storage_path()
self.etcd_daemon = etcd_opts['etcd_daemon_process']
self.ca_certificate = ca_path
self.server_certificate = crt_path
self.server_key = key_path
# Cluster concerns
self.cluster = self.db.get('etcd.cluster', '')
self.token = self.cluster_token()
self.cluster_state = self.db.get('etcd.cluster-state', 'existing')
def set_cluster(self, value):
''' Set the cluster string for peer registration '''
self.cluster = value
self.db.set('etcd.cluster', value)
def set_cluster_state(self, value):
''' Set the cluster state '''
self.cluster_state = value
self.db.set('etcd.cluster-state', value)
def cluster_token(self):
''' Getter to return the unique cluster token. '''
token = leader_get('token')
if not token and is_leader():
token = self.id_generator()
leader_set({'token': token})
return token
def id_generator(self, size=6):
''' Return a random 6 character string for use in cluster init.
@params size - The size of the string to return in characters
'''
chars = string.ascii_uppercase + string.digits
return ''.join(random.choice(chars) for _ in range(size))
def storage_path(self):
''' Storage mounts are limited in snap confinement. Default behavior
is to version the database files in $SNAP_DATA. However the user can
attach durable storage, which is mounted in /media. We need a common
method to determine which storage path we are concerned with '''
etcd_opts = layer.options('etcd')
if is_state('data.volume.attached'):
return "/media/etcd/data"
else:
return etcd_opts['etcd_data_dir']
def get_bind_address(self, endpoint_name):
''' Returns the address that the service binds to. If the config
parameter 'bind_to_all_interfaces' is set to true, it returns 0.0.0.0
If 'bind_to_all_interfaces' is set to false, it returns the
bind address of the endpoint_name received as parameter
@param endpoint_name name the endpoint from where the
bind address is obtained
'''
if bool(config('bind_to_all_interfaces')):
return '0.0.0.0'
return get_bind_address(endpoint_name)