nodepool/nodepool/driver/static/provider.py

468 lines
17 KiB
Python

# Copyright 2017 Red Hat
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import itertools
import logging
import math
import threading
from concurrent.futures.thread import ThreadPoolExecutor
from collections import Counter, namedtuple
from nodepool import exceptions
from nodepool import nodeutils
from nodepool.zk import zookeeper as zk
from nodepool.driver import Provider
from nodepool.driver.utils import NodeDeleter
from nodepool.driver.utils import QuotaInformation, QuotaSupport
from nodepool.driver.static.handler import StaticNodeRequestHandler
class StaticNodeError(Exception):
pass
Node = namedtuple("Node", ["hostname", "username", "port"])
def nodeTuple(node):
"""Return an unique identifier tuple for a static node"""
if isinstance(node, dict):
return Node(node["name"], node["username"], node["connection-port"])
else:
return Node(node.hostname, node.username, node.connection_port)
class StaticNodeProvider(Provider, QuotaSupport):
log = logging.getLogger("nodepool.driver.static."
"StaticNodeProvider")
def __init__(self, provider, *args):
self.provider = provider
# Lock to avoid data races when registering nodes from
# multiple threads (e.g. cleanup and deleted node worker).
self._register_lock = threading.Lock()
def checkHost(self, node):
'''Check node is reachable'''
# only gather host keys if the connection type is ssh or network_cli
gather_hostkeys = (
node["connection-type"] == 'ssh' or
node["connection-type"] == 'network_cli')
if gather_hostkeys and not node.get('host-key-checking', True):
return node['host-key']
try:
keys = nodeutils.nodescan(node["name"],
port=node["connection-port"],
timeout=node["timeout"],
gather_hostkeys=gather_hostkeys)
except exceptions.ConnectionTimeoutException:
raise StaticNodeError(
"{}: ConnectionTimeoutException".format(nodeTuple(node)))
if not gather_hostkeys:
return []
# Check node host-key
if set(node["host-key"]).issubset(set(keys)):
return keys
node_tuple = nodeTuple(node)
self.log.debug("%s: Registered key '%s' not in %s",
node_tuple, node["host-key"], keys)
raise StaticNodeError(
"{}: host key mismatches ({})".format(node_tuple, keys))
def getRegisteredReadyNodes(self, node_tuple):
'''
Get all registered nodes with the given identifier that are READY.
:param Node node_tuple: the namedtuple Node.
:returns: A list of matching Node objects.
'''
nodes = []
for node in self.zk.nodeIterator():
if (node.provider != self.provider.name or
node.state != zk.READY or
node.allocated_to is not None or
nodeTuple(node) != node_tuple
):
continue
nodes.append(node)
return nodes
def checkNodeLiveness(self, node):
node_tuple = nodeTuple(node)
static_node = self.poolNodes().get(node_tuple)
if static_node is None:
return False
if not static_node.get('host-key-checking', True):
# When host-key-checking is disabled, assume the node is live
return True
try:
nodeutils.nodescan(static_node["name"],
port=static_node["connection-port"],
timeout=static_node["timeout"],
gather_hostkeys=False)
return True
except Exception as exc:
self.log.warning("Failed to connect to node %s: %s",
node_tuple, exc)
try:
self.deregisterNode(count=1, node_tuple=node_tuple)
except Exception:
self.log.exception("Couldn't deregister static node:")
return False
def getRegisteredNodes(self):
'''
Get node tuples for all registered static nodes.
:note: We assume hostnames, username and port are unique across pools.
:returns: A set of registered (hostnames, usernames, ports) tuple for
the static driver.
'''
registered = Counter()
for node in self.zk.nodeIterator():
if node.provider != self.provider.name:
continue
registered.update([nodeTuple(node)])
return registered
def registerNodeFromConfig(self, count, provider_name, pool,
static_node):
'''
Register a static node from the config with ZooKeeper.
A node can be registered multiple times to support max-parallel-jobs.
These nodes will share the same node tuple.
:param int count: Number of times to register this node.
:param str provider_name: Name of the provider.
:param str pool: Config of the pool owning the node.
:param dict static_node: The node definition from the config file.
'''
pool_name = pool.name
host_keys = self.checkHost(static_node)
node_tuple = nodeTuple(static_node)
for i in range(0, count):
node = zk.Node()
node.state = zk.READY
node.provider = provider_name
node.pool = pool_name
node.launcher = "static driver"
node.type = static_node["labels"]
node.external_id = static_node["name"]
node.hostname = static_node["name"]
node.username = static_node["username"]
node.interface_ip = static_node["name"]
node.connection_port = static_node["connection-port"]
node.connection_type = static_node["connection-type"]
node.python_path = static_node["python-path"]
node.shell_type = static_node["shell-type"]
nodeutils.set_node_ip(node)
node.host_keys = host_keys
node.attributes = pool.node_attributes
self.zk.storeNode(node)
self.log.debug("Registered static node %s", node_tuple)
def updateNodeFromConfig(self, static_node):
'''
Update a static node in ZooKeeper according to config.
The node is only updated if one of the relevant config items
changed. Name changes of nodes are handled via the
register/deregister flow.
:param dict static_node: The node definition from the config file.
'''
host_keys = self.checkHost(static_node)
node_tuple = nodeTuple(static_node)
nodes = self.getRegisteredReadyNodes(node_tuple)
new_attrs = (
static_node["labels"],
static_node["username"],
static_node["connection-port"],
static_node["connection-type"],
static_node["shell-type"],
static_node["python-path"],
host_keys,
)
for node in nodes:
original_attrs = (node.type, node.username, node.connection_port,
node.shell_type, node.connection_type,
node.python_path, node.host_keys)
if original_attrs == new_attrs:
continue
try:
self.zk.lockNode(node, blocking=False)
node.type = static_node["labels"]
node.username = static_node["username"]
node.connection_port = static_node["connection-port"]
node.connection_type = static_node["connection-type"]
node.shell_type = static_node["shell-type"]
node.python_path = static_node["python-path"]
nodeutils.set_node_ip(node)
node.host_keys = host_keys
except exceptions.ZKLockException:
self.log.warning("Unable to lock node %s for update", node.id)
continue
try:
self.zk.storeNode(node)
self.log.debug("Updated static node %s (id=%s)",
node_tuple, node.id)
finally:
self.zk.unlockNode(node)
def deregisterNode(self, count, node_tuple):
'''
Attempt to delete READY nodes.
We can only delete unlocked READY nodes. If we cannot delete those,
let them remain until they naturally are deleted (we won't re-register
them after they are deleted).
:param Node node_tuple: the namedtuple Node.
'''
self.log.debug("Deregistering %s node(s) matching %s",
count, node_tuple)
nodes = self.getRegisteredReadyNodes(node_tuple)
for node in nodes:
if count <= 0:
break
try:
self.zk.lockNode(node, blocking=False)
except exceptions.ZKLockException:
# It's already locked so skip it.
continue
# Double check the state now that we have a lock since it
# may have changed on us. We keep using the original node
# since it's holding the lock.
_node = self.zk.getNode(node.id)
if _node.state != zk.READY:
# State changed so skip it.
self.zk.unlockNode(node)
continue
node.state = zk.DELETING
try:
self.zk.storeNode(node)
self.log.debug("Deregistered static node: id=%s, "
"node_tuple=%s", node.id, node_tuple)
count = count - 1
except Exception:
self.log.exception("Error deregistering static node:")
finally:
self.zk.unlockNode(node)
def syncNodeCount(self, registered, node, pool):
current_count = registered[nodeTuple(node)]
# Register nodes to synchronize with our configuration.
if current_count < node["max-parallel-jobs"]:
register_cnt = node["max-parallel-jobs"] - current_count
self.registerNodeFromConfig(
register_cnt, self.provider.name, pool, node)
# De-register nodes to synchronize with our configuration.
# This case covers an existing node, but with a decreased
# max-parallel-jobs value.
elif current_count > node["max-parallel-jobs"]:
deregister_cnt = current_count - node["max-parallel-jobs"]
try:
self.deregisterNode(deregister_cnt, nodeTuple(node))
except Exception:
self.log.exception("Couldn't deregister static node:")
def _start(self, zk_conn):
self.zk = zk_conn
registered = self.getRegisteredNodes()
static_nodes = {}
with ThreadPoolExecutor() as executor:
for pool in self.provider.pools.values():
synced_nodes = []
for node in pool.nodes:
synced_nodes.append((node, executor.submit(
self.syncNodeCount, registered, node, pool)))
for node, result in synced_nodes:
try:
result.result()
except StaticNodeError as exc:
self.log.warning("Couldn't sync node: %s", exc)
continue
except Exception:
self.log.exception("Couldn't sync node %s:",
nodeTuple(node))
continue
try:
self.updateNodeFromConfig(node)
except StaticNodeError as exc:
self.log.warning(
"Couldn't update static node: %s", exc)
continue
except Exception:
self.log.exception("Couldn't update static node %s:",
nodeTuple(node))
continue
static_nodes[nodeTuple(node)] = node
# De-register nodes to synchronize with our configuration.
# This case covers any registered nodes that no longer appear in
# the config.
for node in list(registered):
if node not in static_nodes:
try:
self.deregisterNode(registered[node], node)
except Exception:
self.log.exception("Couldn't deregister static node:")
continue
def start(self, zk_conn):
try:
self._start(zk_conn)
except Exception:
self.log.exception("Cannot start static provider:")
def stop(self):
self.log.debug("Stopping")
def listNodes(self):
registered = self.getRegisteredNodes()
servers = []
for pool in self.provider.pools.values():
for node in pool.nodes:
if nodeTuple(node) in registered:
servers.append(node)
return servers
def poolNodes(self):
return {
nodeTuple(n): n
for p in self.provider.pools.values()
for n in p.nodes
}
def startNodeCleanup(self, node):
t = NodeDeleter(self.zk, self, node)
t.start()
return t
def cleanupNode(self, server_id):
return True
def waitForNodeCleanup(self, server_id):
return True
def labelReady(self, name):
return True
def join(self):
return True
def cleanupLeakedResources(self):
with self._register_lock:
registered = self.getRegisteredNodes()
for pool in self.provider.pools.values():
for node in pool.nodes:
try:
self.syncNodeCount(registered, node, pool)
except StaticNodeError as exc:
self.log.warning("Couldn't sync node: %s", exc)
continue
except Exception:
self.log.exception("Couldn't sync node:")
continue
def getRequestHandler(self, poolworker, request):
return StaticNodeRequestHandler(poolworker, request)
def nodeDeletedNotification(self, node):
'''
Re-register the deleted node.
'''
# It's possible a deleted node no longer exists in our config, so
# don't bother to reregister.
node_tuple = nodeTuple(node)
static_node = self.poolNodes().get(node_tuple)
if static_node is None:
return
with self._register_lock:
try:
registered = self.getRegisteredNodes()
except Exception:
self.log.exception(
"Cannot get registered nodes for re-registration:"
)
return
current_count = registered[node_tuple]
# It's possible we were not able to de-register nodes due to a
# config change (because they were in use). In that case, don't
# bother to reregister.
if current_count >= static_node["max-parallel-jobs"]:
return
try:
pool = self.provider.pools[node.pool]
self.registerNodeFromConfig(
1, node.provider, pool, static_node)
except StaticNodeError as exc:
self.log.warning("Cannot re-register deleted node: %s", exc)
except Exception:
self.log.exception("Cannot re-register deleted node %s:",
node_tuple)
def getProviderLimits(self):
return QuotaInformation(
cores=math.inf,
instances=math.inf,
ram=math.inf,
default=math.inf)
def quotaNeededByLabel(self, ntype, pool):
return QuotaInformation(cores=0, instances=1, ram=0, default=1)
def unmanagedQuotaUsed(self):
return QuotaInformation()
def getLabelQuota(self):
label_quota = Counter()
for pool in self.provider.pools.values():
for label in pool.labels:
label_quota[label] = 0
label_quota.update(
itertools.chain.from_iterable(
n.type for n in self.zk.nodeIterator()
if n.state == zk.READY and n.allocated_to is None))
return label_quota