Charmed-Kubernetes/etcd/lib/etcd_databag.py

125 lines
4.5 KiB
Python

from charms import layer
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',
'tls_cipher_suites': '',
'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.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
self.tls_cipher_suites = config("tls_cipher_suites")
# 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)