class EtcdStore(object):
"""Adapter class for etcd api
We will store the services in folders at etcd separated by service_name
version and locaion
/services/{service_name}/{version}/{location} = {location}
So that way we can list all different locations for the same service and
utilize the etcd ttl to expire keys.
Versions, if not provided, will be 1.0 by default when setting values
"""
def __init__(self, host="127.0.0.1", base_path="/services",
**kwargs):
self._connect(host, **kwargs)
self.base_path = base_path
def _connect(self, etcd_location, **kwargs):
self.connection = Client(host=etcd_location, **kwargs)
def get_key(self, service_name, version, location):
key = self._build_path(service_name, version, location)
items = self.connection.read(key, recursive=True)
return [item.value for item in items.children]
def set_key(self, service_name, version, location, ttl=None):
assert location
if not version:
version = '1.0'
key = self._build_path(service_name, version, location)
return bool(self.connection.set(key, location, ttl=ttl))
def delete_key(self, service_name, version, location):
"version and location cannot be None"
assert version
assert location
key = self._build_path(service_name, version, location)
return bool(self.connection.delete(key))
def _build_path(self, service_name, version, location):
"Builds the query path for the value in the etcd"
assert service_name # service_name is the minimum requirement
key = "{0}/{1}".format(self.base_path, service_name)
if version:
key = "{0}/{1}".format(key, version)
if location:
key = "{0}/{1}".format(key, location)
return key
def _extract_key(self, path):
"Removes Base Path of the key"
return path.split("{0}/".format(self.base_path)).pop()
