5:13 a.m.
From: Ondrej Lichtner <olichtne(a)redhat.com>
Defines the MachineMapper class. Implements a matching algorithm that
maps requirements to available hosts. In this specific class this is
implemented with backtracking, however testers are free to implement
their own algorithm as long as they respect the API of this class as it
needs to integrate with the rest of LNST.
Most of this class is based on the SetupMapper class and includes some
functionality from the old SlavePool class, but has been modified to
work with Python Recipes.
Signed-off-by: Ondrej Lichtner <olichtne(a)redhat.com>
---
v2:
* docstring now explains that implementing your own MachineMapper is
not supported at this moment
* removed debug pprint import
---
lnst/Controller/MachineMapper.py | 328 +++++++++++++++++++++++++++++++++++++++
1 file changed, 328 insertions(+)
create mode 100644 lnst/Controller/MachineMapper.py
diff --git a/lnst/Controller/MachineMapper.py b/lnst/Controller/MachineMapper.py
new file mode 100644
index 0000000..8f98ef9
--- /dev/null
+++ b/lnst/Controller/MachineMapper.py
@@ -0,0 +1,328 @@
+"""
+Defines the MachineMapper class.
+
+Copyright 2017 Red Hat, Inc.
+Licensed under the GNU General Public License, version 2 as
+published by the Free Software Foundation; see COPYING for details.
+"""
+
+__author__ = """
+olichtne(a)redhat.com (Ondrej Lichtner)
+"""
+
+import logging
+from lnst.Controller.Common import ControllerError
+
+class MapperError(ControllerError):
+ pass
+
+class MachineMapper(object):
+ """Implements a matching algorithm that maps requirements to available
hosts
+
+ In this specific class this is implemented with backtracking, however
+ testers are free to implement their own algorithm as long as they respect
+ the API of this class as it needs to integrate with the rest of LNST.
+
+ Since the API is not fully defined yet and depends on the interaction with
+ the SlavePoolManager (also needs a fully defined API), implementing your
+ own MachineMapper class is not recommended yet. However since, the
+ Controller class accepts the 'mapper' parameter it is possible if done
+ properly.
+
+ TODO The Interface will be separated into an abstract class to clearly
+ define the required API. ABC?
+ """
+ def __init__(self):
+ self._pools = {}
+ self._pool_stack = []
+ self._pool = {}
+ self._pool_name = None
+ self._mreqs = {}
+ self._unmatched_req_machines = []
+ self._matched_pool_machines = []
+ self._machine_stack = []
+ self._net_label_mapping = {}
+ self._virtual_matching = False
+
+ def set_requirements(self, mreqs):
+ """set the requirements to be used by the matching algorithm
+
+ This should be a specially formatted dictionary to work.
+ TODO Should probably be reworked to work with something more
+ flexible.
+ """
+ self._mreqs = mreqs
+
+ def set_pools(self, pools):
+ """set the pools to be used by the matching algorithm
+
+ This needs to be a specially formatted dictionary returned by get_pools
+ method of a SlavePoolManager class.
+ """
+ self._pools = pools
+
+ def reset_match_state(self):
+ """resets the state of the backtracking
algorithm"""
+ self._net_label_mapping = {}
+ self._machine_stack = []
+ self._unmatched_req_machines = sorted(self._mreqs.keys(), reverse=True)
+
+ self._pool_stack = list(self._pools.keys())
+ if len(self._pool_stack) > 0:
+ self._pool_name = self._pool_stack.pop()
+ self._pool = self._pools[self._pool_name]
+
+ self._unmatched_pool_machines = []
+ for p_id, p_machine in sorted(self._pool.iteritems(), reverse=True):
+ if self._virtual_matching:
+ if "libvirt_domain" in p_machine["params"]:
+ self._unmatched_pool_machines.append(p_id)
+ else:
+ self._unmatched_pool_machines.append(p_id)
+
+ if len(self._pool) > 0 and len(self._mreqs) > 0:
+ self._push_machine_stack()
+
+ def matches(self, **kwargs):
+ """Generator method which calls the matching algorithm
+
+ Args:
+ multimatch -- if False or not specified, will only return the first
+ match. Otherwise repeated calls of this method will return
+ more possible mappings until no more are possible.
+
+ Returns:
+ The matched mapping or requirements to pool Machines.
+ """
+ logging.info("Matching machines, without virtuals.")
+ self.reset_match_state()
+ matched = False
+
+ while self._match():
+ matched = True
+ yield self.get_mapping()
+ if "multimatch" not in kwargs or not
kwargs["multimatch"]:
+ return
+
+ if "allow_virt" in kwargs and kwargs["allow_virt"]:
+ logging.info("Match failed for normal machines, falling back "\
+ "to matching virtual machines.")
+ self._virtual_matching = True
+ self.reset_match_state()
+ while self._match():
+ matched = True
+ yield self.get_mapping()
+ if "multimatch" not in kwargs or not
kwargs["multimatch"]:
+ return
+ if not matched:
+ msg = "This setup cannot be provisioned with the current pool."
+ raise MapperError(msg)
+
+ def _match(self):
+ logging.info("Trying match with pool: %s" % self._pool_name)
+ while len(self._machine_stack)>0:
+ stack_top = self._machine_stack[-1]
+ if self._virtual_matching and stack_top["virt_matched"]:
+ if stack_top["current_match"] != None:
+ cur_match = stack_top["current_match"]
+ self._unmatched_pool_machines.append(cur_match)
+ stack_top["current_match"] = None
+ stack_top["virt_matched"] = False
+
+ if self._if_match():
+ if len(self._unmatched_req_machines) > 0:
+ self._push_machine_stack()
+ continue
+ else:
+ return True
+ else:
+ #unmap the pool machine
+ if stack_top["current_match"] != None:
+ cur_match = stack_top["current_match"]
+ self._unmatched_pool_machines.append(cur_match)
+ stack_top["current_match"] = None
+
+ mreq_m_id = stack_top["m_id"]
+ while len(stack_top["remaining_matches"]) > 0:
+ pool_m_id = stack_top["remaining_matches"].pop()
+ if self._check_machine_compatibility(mreq_m_id, pool_m_id):
+ #map compatible pool machine
+ stack_top["current_match"] = pool_m_id
+ stack_top["unmatched_pool_ifs"] = \
+ sorted(self._pool[pool_m_id]["interfaces"].keys(),
+ reverse=True)
+ self._unmatched_pool_machines.remove(pool_m_id)
+ break
+
+ if stack_top["current_match"] != None:
+ #clear if mapping
+ stack_top["if_stack"] = []
+ #next iteration will match the interfaces
+ if not self._virtual_matching:
+ self._push_if_stack()
+ continue
+ else:
+ self._pop_machine_stack()
+ if len(self._machine_stack) == 0 and\
+ len(self._pool_stack) > 0:
+ logging.info("Match with pool %s not found." %
+ self._pool_name)
+ self._pool_name = self._pool_stack.pop()
+ self._pool = self._pools[self._pool_name]
+ logging.info("Trying match with pool: %s" %
+ self._pool_name)
+
+ self._unmatched_pool_machines = []
+ for p_id, p_machine in sorted(self._pool.iteritems(),
reverse=True):
+ if self._virtual_matching:
+ if "libvirt_domain" in
p_machine["params"]:
+ self._unmatched_pool_machines.append(p_id)
+ else:
+ self._unmatched_pool_machines.append(p_id)
+
+ if len(self._pool) > 0 and len(self._mreqs) > 0:
+ self._push_machine_stack()
+ continue
+ return False
+
+ def _if_match(self):
+ m_stack_top = self._machine_stack[-1]
+ if_stack = m_stack_top["if_stack"]
+
+ if self._virtual_matching:
+ if m_stack_top["current_match"] != None:
+ m_stack_top["virt_matched"] = True
+ return True
+ else:
+ return False
+
+ while len(if_stack) > 0:
+ stack_top = if_stack[-1]
+
+ req_m = self._mreqs[m_stack_top["m_id"]]
+ pool_m = self._pool[m_stack_top["current_match"]]
+ req_if = req_m["interfaces"][stack_top["if_id"]]
+ req_net_label = req_if["network"]
+
+ if stack_top["current_match"] != None:
+ cur_match = stack_top["current_match"]
+ m_stack_top["unmatched_pool_ifs"].append(cur_match)
+ pool_if = pool_m["interfaces"][cur_match]
+ pool_net_label = pool_if["network"]
+ net_label_mapping = self._net_label_mapping[req_net_label]
+ if net_label_mapping == (pool_net_label, m_stack_top["m_id"],
+ stack_top["if_id"]):
+ del self._net_label_mapping[req_net_label]
+ stack_top["current_match"] = None
+
+ while len(stack_top["remaining_matches"]) > 0:
+ pool_if_id = stack_top["remaining_matches"].pop()
+ pool_if = pool_m["interfaces"][pool_if_id]
+ if self._check_interface_compatibility(req_if, pool_if):
+ #map compatible interfaces
+ stack_top["current_match"] = pool_if_id
+ if req_net_label not in self._net_label_mapping:
+ self._net_label_mapping[req_net_label] =\
+ (pool_if["network"],
+ m_stack_top["m_id"],
+ stack_top["if_id"])
+ m_stack_top["unmatched_pool_ifs"].remove(pool_if_id)
+ break
+
+ if stack_top["current_match"] != None:
+ if len(m_stack_top["unmatched_ifs"]) > 0:
+ self._push_if_stack()
+ continue
+ else:
+ return True
+ else:
+ self._pop_if_stack()
+ continue
+ return False
+
+ def _push_machine_stack(self):
+ machine_match = {}
+ machine_match["m_id"] = self._unmatched_req_machines.pop()
+ machine_match["current_match"] = None
+ machine_match["remaining_matches"] =
list(self._unmatched_pool_machines)
+ machine_match["if_stack"] = []
+
+ machine = self._mreqs[machine_match["m_id"]]
+ machine_match["unmatched_ifs"] =
sorted(machine["interfaces"].keys(),
+ reverse=True)
+ machine_match["unmatched_pool_ifs"] = []
+
+ if self._virtual_matching:
+ machine_match["virt_matched"] = False
+
+ self._machine_stack.append(machine_match)
+
+ def _pop_machine_stack(self):
+ stack_top = self._machine_stack.pop()
+ self._unmatched_req_machines.append(stack_top["m_id"])
+
+ def _push_if_stack(self):
+ m_stack_top = self._machine_stack[-1]
+ if_match = {}
+ if_match["if_id"] = m_stack_top["unmatched_ifs"].pop()
+ if_match["current_match"] = None
+ if_match["remaining_matches"] =
list(m_stack_top["unmatched_pool_ifs"])
+
+ m_stack_top["if_stack"].append(if_match)
+
+ def _pop_if_stack(self):
+ m_stack_top = self._machine_stack[-1]
+ if_stack_top = m_stack_top["if_stack"].pop()
+ m_stack_top["unmatched_ifs"].append(if_stack_top["if_id"])
+
+ def _check_machine_compatibility(self, req_id, pool_id):
+ req_machine = self._mreqs[req_id]
+ pool_machine = self._pool[pool_id]
+ for param, value in req_machine["params"].iteritems():
+ if param not in pool_machine["params"] or\
+ value != pool_machine["params"][param]:
+ return False
+ return True
+
+ def _check_interface_compatibility(self, req_if, pool_if):
+ label_mapping = self._net_label_mapping
+ for req_label, mapping in label_mapping.iteritems():
+ if req_label == req_if["network"] and\
+ mapping[0] != pool_if["network"]:
+ return False
+ if mapping[0] == pool_if["network"] and\
+ req_label != req_if["network"]:
+ return False
+ for param, value in req_if["params"].iteritems():
+ if param not in pool_if["params"] or\
+ value != pool_if["params"][param]:
+ return False
+ return True
+
+ def get_mapping(self):
+ mapping = {"machines": {}, "networks": {},
"virtual": False,
+ "pool_name": self._pool_name}
+
+ for req_label, label_map in self._net_label_mapping.iteritems():
+ mapping["networks"][req_label] = label_map[0]
+
+ for machine in self._machine_stack:
+ m_map = mapping["machines"][machine["m_id"]] = {}
+
+ m_map["target"] = machine["current_match"]
+
+ hostname =
self._pool[m_map["target"]]["params"]["hostname"]
+ m_map["hostname"] = hostname
+
+ interfaces = m_map["interfaces"] = {}
+ if_stack = machine["if_stack"]
+ for interface in if_stack:
+ i = interfaces[interface["if_id"]] = {}
+ i["target"] = interface["current_match"]
+ pool_if =
self._pool[m_map["target"]]["interfaces"][i["target"]]
+ i["hwaddr"] = pool_if["params"]["hwaddr"]
+
+
+ if self._virtual_matching:
+ mapping["virtual"] = True
+ return mapping
--
2.13.0