NG-RO/osm_ng_ro/ns_thread.py

# -*- coding: utf-8 -*-

##
# Copyright 2020 Telefonica Investigacion y Desarrollo, S.A.U.
#
# 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.
#
##

""""
This is thread that interacts with a VIM. It processes TASKs sequentially against a single VIM.
The tasks are stored at database in table ro_tasks
A single ro_task refers to a VIM element (flavor, image, network, ...).
A ro_task can contain several 'tasks', each one with a target, where to store the results
"""

import threading
import time
import queue
import logging
import yaml
from pkg_resources import iter_entry_points
# from osm_common import dbmongo, dbmemory, fslocal, fsmongo, msglocal, msgkafka, version as common_version
from osm_common.dbbase import DbException
# from osm_common.fsbase import FsException
# from osm_common.msgbase import MsgException
from osm_ro_plugin.vim_dummy import VimDummyConnector
from osm_ro_plugin.sdn_dummy import SdnDummyConnector
from osm_ro_plugin import vimconn, sdnconn
from copy import deepcopy
from unittest.mock import Mock
from http import HTTPStatus
from os import mkdir
from shutil import rmtree

__author__ = "Alfonso Tierno"
__date__ = "$28-Sep-2017 12:07:15$"


def deep_get(target_dict, *args, **kwargs):
    """
    Get a value from target_dict entering in the nested keys. If keys does not exist, it returns None
    Example target_dict={a: {b: 5}}; key_list=[a,b] returns 5; both key_list=[a,b,c] and key_list=[f,h] return None
    :param target_dict: dictionary to be read
    :param args: list of keys to read from  target_dict
    :param kwargs: only can contain default=value to return if key is not present in the nested dictionary
    :return: The wanted value if exist, None or default otherwise
    """
    for key in args:
        if not isinstance(target_dict, dict) or key not in target_dict:
            return kwargs.get("default")
        target_dict = target_dict[key]
    return target_dict


class NsWorkerException(Exception):
    pass


class FailingConnector:
    def __init__(self, error_msg):
        self.error_msg = error_msg
        for method in dir(vimconn.VimConnector):
            if method[0] != "_":
                setattr(self, method, Mock(side_effect=vimconn.VimConnException(error_msg)))
        for method in dir(sdnconn.SdnConnectorBase):
            if method[0] != "_":
                setattr(self, method, Mock(side_effect=sdnconn.SdnConnectorError(error_msg)))


class NsWorkerExceptionNotFound(NsWorkerException):
    pass


class VimInteractionBase:
    """ Base class to call VIM/SDN for creating, deleting and refresh networks, VMs, flavors, ...
    It implements methods that does nothing and return ok"""
    def __init__(self, db, my_vims, db_vims, logger):
        self.db = db
        self.logger = logger
        self.my_vims = my_vims
        self.db_vims = db_vims

    def new(self, ro_task, task_index, task_depends):
        return "BUILD", {}

    def refresh(self, ro_task):
        """skip calling VIM to get image, flavor status. Assumes ok"""
        if ro_task["vim_info"]["vim_status"] == "VIM_ERROR":
            return "FAILED", {}
        return "DONE", {}

    def delete(self, ro_task, task_index):
        """skip calling VIM to delete image. Assumes ok"""
        return "DONE", {}

    def exec(self, ro_task, task_index, task_depends):
        return "DONE", None, None


class VimInteractionNet(VimInteractionBase):

    def new(self, ro_task, task_index, task_depends):
        vim_net_id = None
        task = ro_task["tasks"][task_index]
        task_id = task["task_id"]
        created = False
        created_items = {}
        target_vim = self.my_vims[ro_task["target_id"]]
        try:
            # FIND
            if task.get("find_params"):
                # if management, get configuration of VIM
                if task["find_params"].get("filter_dict"):
                    vim_filter = task["find_params"]["filter_dict"]
                elif task["find_params"].get("mgmt"):   # mamagement network
                    if deep_get(self.db_vims[ro_task["target_id"]], "config", "management_network_id"):
                        vim_filter = {"id": self.db_vims[ro_task["target_id"]]["config"]["management_network_id"]}
                    elif deep_get(self.db_vims[ro_task["target_id"]], "config", "management_network_name"):
                        vim_filter = {"name": self.db_vims[ro_task["target_id"]]["config"]["management_network_name"]}
                    else:
                        vim_filter = {"name": task["find_params"]["name"]}
                else:
                    raise NsWorkerExceptionNotFound("Invalid find_params for new_net {}".format(task["find_params"]))

                vim_nets = target_vim.get_network_list(vim_filter)
                if not vim_nets and not task.get("params"):
                    raise NsWorkerExceptionNotFound("Network not found with this criteria: '{}'".format(
                        task.get("find_params")))
                elif len(vim_nets) > 1:
                    raise NsWorkerException(
                        "More than one network found with this criteria: '{}'".format(task["find_params"]))
                if vim_nets:
                    vim_net_id = vim_nets[0]["id"]
            else:
                # CREATE
                params = task["params"]
                vim_net_id, created_items = target_vim.new_network(**params)
                created = True

            ro_vim_item_update = {"vim_id": vim_net_id,
                                  "vim_status": "BUILD",
                                  "created": created,
                                  "created_items": created_items,
                                  "vim_details": None}
            self.logger.debug(
                "task={} {} new-net={} created={}".format(task_id, ro_task["target_id"], vim_net_id, created))
            return "BUILD", ro_vim_item_update
        except (vimconn.VimConnException, NsWorkerException) as e:
            self.logger.error("task={} vim={} new-net: {}".format(task_id, ro_task["target_id"], e))
            ro_vim_item_update = {"vim_status": "VIM_ERROR",
                                  "created": created,
                                  "vim_details": str(e)}
            return "FAILED", ro_vim_item_update

    def refresh(self, ro_task):
        """Call VIM to get network status"""
        ro_task_id = ro_task["_id"]
        target_vim = self.my_vims[ro_task["target_id"]]

        vim_id = ro_task["vim_info"]["vim_id"]
        net_to_refresh_list = [vim_id]
        try:
            vim_dict = target_vim.refresh_nets_status(net_to_refresh_list)
            vim_info = vim_dict[vim_id]
            if vim_info["status"] == "ACTIVE":
                task_status = "DONE"
            elif vim_info["status"] == "BUILD":
                task_status = "BUILD"
            else:
                task_status = "FAILED"
        except vimconn.VimConnException as e:
            # Mark all tasks at VIM_ERROR status
            self.logger.error("ro_task={} vim={} get-net={}: {}".format(ro_task_id, ro_task["target_id"], vim_id, e))
            vim_info = {"status": "VIM_ERROR", "error_msg": str(e)}
            task_status = "FAILED"

        ro_vim_item_update = {}
        if ro_task["vim_info"]["vim_status"] != vim_info["status"]:
            ro_vim_item_update["vim_status"] = vim_info["status"]
        if ro_task["vim_info"]["vim_name"] != vim_info.get("name"):
            ro_vim_item_update["vim_name"] = vim_info.get("name")
        if vim_info["status"] in ("ERROR", "VIM_ERROR"):
            if ro_task["vim_info"]["vim_details"] != vim_info.get("error_msg"):
                ro_vim_item_update["vim_details"] = vim_info.get("error_msg")
        elif vim_info["status"] == "DELETED":
            ro_vim_item_update["vim_id"] = None
            ro_vim_item_update["vim_details"] = "Deleted externally"
        else:
            if ro_task["vim_info"]["vim_details"] != vim_info["vim_info"]:
                ro_vim_item_update["vim_details"] = vim_info["vim_info"]
        if ro_vim_item_update:
            self.logger.debug("ro_task={} {} get-net={}: status={} {}".format(
                ro_task_id, ro_task["target_id"], vim_id, ro_vim_item_update.get("vim_status"),
                ro_vim_item_update.get("vim_details") if ro_vim_item_update.get("vim_status") != "ACTIVE" else ''))
        return task_status, ro_vim_item_update

    def delete(self, ro_task, task_index):
        task = ro_task["tasks"][task_index]
        task_id = task["task_id"]
        net_vim_id = ro_task["vim_info"]["vim_id"]
        ro_vim_item_update_ok = {"vim_status": "DELETED",
                                 "created": False,
                                 "vim_details": "DELETED",
                                 "vim_id": None}
        try:
            if net_vim_id or ro_task["vim_info"]["created_items"]:
                target_vim = self.my_vims[ro_task["target_id"]]
                target_vim.delete_network(net_vim_id, ro_task["vim_info"]["created_items"])

        except vimconn.VimConnNotFoundException:
            ro_vim_item_update_ok["vim_details"] = "already deleted"

        except vimconn.VimConnException as e:
            self.logger.error("ro_task={} vim={} del-net={}: {}".format(ro_task["_id"], ro_task["target_id"],
                                                                        net_vim_id, e))
            ro_vim_item_update = {"vim_status": "VIM_ERROR",
                                  "vim_details": "Error while deleting: {}".format(e)}
            return "FAILED", ro_vim_item_update

        self.logger.debug("task={} {} del-net={} {}".format(task_id, ro_task["target_id"], net_vim_id,
                                                            ro_vim_item_update_ok.get("vim_details", "")))
        return "DONE", ro_vim_item_update_ok


class VimInteractionVdu(VimInteractionBase):
    max_retries_inject_ssh_key = 20    # 20 times
    time_retries_inject_ssh_key = 30   # wevery 30 seconds

    def new(self, ro_task, task_index, task_depends):
        task = ro_task["tasks"][task_index]
        task_id = task["task_id"]
        created = False
        created_items = {}
        target_vim = self.my_vims[ro_task["target_id"]]
        try:
            created = True
            params = task["params"]
            params_copy = deepcopy(params)
            net_list = params_copy["net_list"]
            for net in net_list:
                if "net_id" in net and net["net_id"].startswith("TASK-"):  # change task_id into network_id
                    network_id = task_depends[net["net_id"]]
                    if not network_id:
                        raise NsWorkerException("Cannot create VM because depends on a network not created or found "
                                                "for {}".format(net["net_id"]))
                    net["net_id"] = network_id
            if params_copy["image_id"].startswith("TASK-"):
                params_copy["image_id"] = task_depends[params_copy["image_id"]]
            if params_copy["flavor_id"].startswith("TASK-"):
                params_copy["flavor_id"] = task_depends[params_copy["flavor_id"]]

            vim_vm_id, created_items = target_vim.new_vminstance(**params_copy)
            interfaces = [iface["vim_id"] for iface in params_copy["net_list"]]

            ro_vim_item_update = {"vim_id": vim_vm_id,
                                  "vim_status": "BUILD",
                                  "created": created,
                                  "created_items": created_items,
                                  "vim_details": None,
                                  "interfaces_vim_ids": interfaces,
                                  "interfaces": [],
                                  }
            self.logger.debug(
                "task={} {} new-vm={} created={}".format(task_id, ro_task["target_id"], vim_vm_id, created))
            return "BUILD", ro_vim_item_update
        except (vimconn.VimConnException, NsWorkerException) as e:
            self.logger.error("task={} {} new-vm: {}".format(task_id, ro_task["target_id"], e))
            ro_vim_item_update = {"vim_status": "VIM_ERROR",
                                  "created": created,
                                  "vim_details": str(e)}
            return "FAILED", ro_vim_item_update

    def delete(self, ro_task, task_index):
        task = ro_task["tasks"][task_index]
        task_id = task["task_id"]
        vm_vim_id = ro_task["vim_info"]["vim_id"]
        ro_vim_item_update_ok = {"vim_status": "DELETED",
                                 "created": False,
                                 "vim_details": "DELETED",
                                 "vim_id": None}
        try:
            if vm_vim_id or ro_task["vim_info"]["created_items"]:
                target_vim = self.my_vims[ro_task["target_id"]]
                target_vim.delete_vminstance(vm_vim_id, ro_task["vim_info"]["created_items"])

        except vimconn.VimConnNotFoundException:
            ro_vim_item_update_ok["vim_details"] = "already deleted"

        except vimconn.VimConnException as e:
            self.logger.error("ro_task={} vim={} del-vm={}: {}".format(ro_task["_id"], ro_task["target_id"],
                                                                       vm_vim_id, e))
            ro_vim_item_update = {"vim_status": "VIM_ERROR",
                                  "vim_details": "Error while deleting: {}".format(e)}
            return "FAILED", ro_vim_item_update

        self.logger.debug("task={} {} del-vm={} {}".format(task_id, ro_task["target_id"], vm_vim_id,
                                                           ro_vim_item_update_ok.get("vim_details", "")))
        return "DONE", ro_vim_item_update_ok

    def refresh(self, ro_task):
        """Call VIM to get vm status"""
        ro_task_id = ro_task["_id"]
        target_vim = self.my_vims[ro_task["target_id"]]

        vim_id = ro_task["vim_info"]["vim_id"]
        if not vim_id:
            return None, None
        vm_to_refresh_list = [vim_id]
        try:
            vim_dict = target_vim.refresh_vms_status(vm_to_refresh_list)
            vim_info = vim_dict[vim_id]
            if vim_info["status"] == "ACTIVE":
                task_status = "DONE"
            elif vim_info["status"] == "BUILD":
                task_status = "BUILD"
            else:
                task_status = "FAILED"
            # try to load and parse vim_information
            try:
                vim_info_info = yaml.safe_load(vim_info["vim_info"])
                if vim_info_info.get("name"):
                    vim_info["name"] = vim_info_info["name"]
            except Exception:
                pass
        except vimconn.VimConnException as e:
            # Mark all tasks at VIM_ERROR status
            self.logger.error("ro_task={} vim={} get-vm={}: {}".format(ro_task_id, ro_task["target_id"], vim_id, e))
            vim_info = {"status": "VIM_ERROR", "error_msg": str(e)}
            task_status = "FAILED"

        ro_vim_item_update = {}
        # Interfaces cannot be present if e.g. VM is not present, that is status=DELETED
        vim_interfaces = []
        if vim_info.get("interfaces"):
            for vim_iface_id in ro_task["vim_info"]["interfaces_vim_ids"]:
                iface = next((iface for iface in vim_info["interfaces"] if vim_iface_id == iface["vim_interface_id"]),
                             None)
                # if iface:
                #     iface.pop("vim_info", None)
                vim_interfaces.append(iface)

        task_create = next(t for t in ro_task["tasks"] if t and t["action"] == "CREATE" and t["status"] != "FINISHED")
        if vim_interfaces and task_create.get("mgmt_vnf_interface") is not None:
            vim_interfaces[task_create["mgmt_vnf_interface"]]["mgmt_vnf_interface"] = True
        mgmt_vdu_iface = task_create.get("mgmt_vdu_interface", task_create.get("mgmt_vnf_interface", 0))
        if vim_interfaces:
            vim_interfaces[mgmt_vdu_iface]["mgmt_vdu_interface"] = True

        if ro_task["vim_info"]["interfaces"] != vim_interfaces:
            ro_vim_item_update["interfaces"] = vim_interfaces
        if ro_task["vim_info"]["vim_status"] != vim_info["status"]:
            ro_vim_item_update["vim_status"] = vim_info["status"]
        if ro_task["vim_info"]["vim_name"] != vim_info.get("name"):
            ro_vim_item_update["vim_name"] = vim_info.get("name")
        if vim_info["status"] in ("ERROR", "VIM_ERROR"):
            if ro_task["vim_info"]["vim_details"] != vim_info.get("error_msg"):
                ro_vim_item_update["vim_details"] = vim_info.get("error_msg")
        elif vim_info["status"] == "DELETED":
            ro_vim_item_update["vim_id"] = None
            ro_vim_item_update["vim_details"] = "Deleted externally"
        else:
            if ro_task["vim_info"]["vim_details"] != vim_info["vim_info"]:
                ro_vim_item_update["vim_details"] = vim_info["vim_info"]
        if ro_vim_item_update:
            self.logger.debug("ro_task={} {} get-vm={}: status={} {}".format(
                ro_task_id, ro_task["target_id"], vim_id, ro_vim_item_update.get("vim_status"),
                ro_vim_item_update.get("vim_details") if ro_vim_item_update.get("vim_status") != "ACTIVE" else ''))
        return task_status, ro_vim_item_update

    def exec(self, ro_task, task_index, task_depends):
        task = ro_task["tasks"][task_index]
        task_id = task["task_id"]
        target_vim = self.my_vims[ro_task["target_id"]]
        db_task_update = {"retries": 0}
        retries = task.get("retries", 0)
        try:
            params = task["params"]
            params_copy = deepcopy(params)
            params_copy["ro_key"] = self.db.decrypt(params_copy.pop("private_key"),
                                                    params_copy.pop("schema_version"), params_copy.pop("salt"))
            params_copy["ip_addr"] = params_copy.pop("ip_address")
            target_vim.inject_user_key(**params_copy)
            self.logger.debug(
                "task={} {} action-vm=inject_key".format(task_id, ro_task["target_id"]))
            return "DONE", None, db_task_update,    # params_copy["key"]
        except (vimconn.VimConnException, NsWorkerException) as e:
            retries += 1
            if retries < self.max_retries_inject_ssh_key:
                return "BUILD", None, {"retries": retries, "next_retry": self.time_retries_inject_ssh_key}
            self.logger.error("task={} {} inject-ssh-key: {}".format(task_id, ro_task["target_id"], e))
            ro_vim_item_update = {"vim_details": str(e)}
            return "FAILED", ro_vim_item_update, db_task_update


class VimInteractionImage(VimInteractionBase):

    def new(self, ro_task, task_index, task_depends):
        task = ro_task["tasks"][task_index]
        task_id = task["task_id"]
        created = False
        created_items = {}
        target_vim = self.my_vims[ro_task["target_id"]]
        try:
            # FIND
            if task.get("find_params"):
                vim_images = target_vim.get_image_list(**task["find_params"])
                if not vim_images:
                    raise NsWorkerExceptionNotFound("Image not found with this criteria: '{}'".format(
                        task["find_params"]))
                elif len(vim_images) > 1:
                    raise NsWorkerException(
                        "More than one network found with this criteria: '{}'".format(task["find_params"]))
                else:
                    vim_image_id = vim_images[0]["id"]

            ro_vim_item_update = {"vim_id": vim_image_id,
                                  "vim_status": "DONE",
                                  "created": created,
                                  "created_items": created_items,
                                  "vim_details": None}
            self.logger.debug(
                "task={} {} new-image={} created={}".format(task_id, ro_task["target_id"], vim_image_id, created))
            return "DONE", ro_vim_item_update
        except (NsWorkerException, vimconn.VimConnException) as e:
            self.logger.error("task={} {} new-image: {}".format(task_id, ro_task["target_id"], e))
            ro_vim_item_update = {"vim_status": "VIM_ERROR",
                                  "created": created,
                                  "vim_details": str(e)}
            return "FAILED", ro_vim_item_update


class VimInteractionFlavor(VimInteractionBase):

    def delete(self, ro_task, task_index):
        task = ro_task["tasks"][task_index]
        task_id = task["task_id"]
        flavor_vim_id = ro_task["vim_info"]["vim_id"]
        ro_vim_item_update_ok = {"vim_status": "DELETED",
                                 "created": False,
                                 "vim_details": "DELETED",
                                 "vim_id": None}
        try:
            if flavor_vim_id:
                target_vim = self.my_vims[ro_task["target_id"]]
                target_vim.delete_flavor(flavor_vim_id)

        except vimconn.VimConnNotFoundException:
            ro_vim_item_update_ok["vim_details"] = "already deleted"

        except vimconn.VimConnException as e:
            self.logger.error("ro_task={} vim={} del-flavor={}: {}".format(
                ro_task["_id"], ro_task["target_id"], flavor_vim_id, e))
            ro_vim_item_update = {"vim_status": "VIM_ERROR",
                                  "vim_details": "Error while deleting: {}".format(e)}
            return "FAILED", ro_vim_item_update

        self.logger.debug("task={} {} del-flavor={} {}".format(
            task_id, ro_task["target_id"], flavor_vim_id, ro_vim_item_update_ok.get("vim_details", "")))
        return "DONE", ro_vim_item_update_ok

    def new(self, ro_task, task_index, task_depends):
        task = ro_task["tasks"][task_index]
        task_id = task["task_id"]
        created = False
        created_items = {}
        target_vim = self.my_vims[ro_task["target_id"]]
        try:
            # FIND
            vim_flavor_id = None
            if task.get("find_params"):
                try:
                    flavor_data = task["find_params"]["flavor_data"]
                    vim_flavor_id = target_vim.get_flavor_id_from_data(flavor_data)
                except vimconn.VimConnNotFoundException:
                    pass

            if not vim_flavor_id and task.get("params"):
                # CREATE
                flavor_data = task["params"]["flavor_data"]
                vim_flavor_id = target_vim.new_flavor(flavor_data)
                created = True

            ro_vim_item_update = {"vim_id": vim_flavor_id,
                                  "vim_status": "DONE",
                                  "created": created,
                                  "created_items": created_items,
                                  "vim_details": None}
            self.logger.debug(
                "task={} {} new-flavor={} created={}".format(task_id, ro_task["target_id"], vim_flavor_id, created))
            return "DONE", ro_vim_item_update
        except (vimconn.VimConnException, NsWorkerException) as e:
            self.logger.error("task={} vim={} new-flavor: {}".format(task_id, ro_task["target_id"], e))
            ro_vim_item_update = {"vim_status": "VIM_ERROR",
                                  "created": created,
                                  "vim_details": str(e)}
            return "FAILED", ro_vim_item_update


class VimInteractionSdnNet(VimInteractionBase):

    @staticmethod
    def _match_pci(port_pci, mapping):
        """
        Check if port_pci matches with mapping
        mapping can have brackets to indicate that several chars are accepted. e.g
        pci '0000:af:10.1' matches with '0000:af:1[01].[1357]'
        :param port_pci: text
        :param mapping: text, can contain brackets to indicate several chars are available
        :return: True if matches, False otherwise
        """
        if not port_pci or not mapping:
            return False
        if port_pci == mapping:
            return True

        mapping_index = 0
        pci_index = 0
        while True:
            bracket_start = mapping.find("[", mapping_index)
            if bracket_start == -1:
                break
            bracket_end = mapping.find("]", bracket_start)
            if bracket_end == -1:
                break
            length = bracket_start - mapping_index
            if length and port_pci[pci_index:pci_index + length] != mapping[mapping_index:bracket_start]:
                return False
            if port_pci[pci_index + length] not in mapping[bracket_start+1:bracket_end]:
                return False
            pci_index += length + 1
            mapping_index = bracket_end + 1

        if port_pci[pci_index:] != mapping[mapping_index:]:
            return False
        return True

    def _get_interfaces(self, vlds_to_connect, vim_account_id):
        """
        :param vlds_to_connect: list with format vnfrs:<id>:vld.<vld_id> or nsrs:<id>:vld.<vld_id>
        :param vim_account_id:
        :return:
        """
        interfaces = []
        for vld in vlds_to_connect:
            table, _, db_id = vld.partition(":")
            db_id, _, vld = db_id.partition(":")
            _, _, vld_id = vld.partition(".")
            if table == "vnfrs":
                q_filter = {"vim-account-id": vim_account_id, "_id": db_id}
                iface_key = "vnf-vld-id"
            else:  # table == "nsrs"
                q_filter = {"vim-account-id": vim_account_id, "nsr-id-ref": db_id}
                iface_key = "ns-vld-id"
            db_vnfrs = self.db.get_list("vnfrs", q_filter=q_filter)
            for db_vnfr in db_vnfrs:
                for vdu_index, vdur in enumerate(db_vnfr.get("vdur", ())):
                    for iface_index, interface in enumerate(vdur["interfaces"]):
                        if interface.get(iface_key) == vld_id and \
                                interface.get("type") in ("SR-IOV", "PCI-PASSTHROUGH"):
                            # only SR-IOV o PT
                            interface_ = interface.copy()
                            interface_["id"] = "vnfrs:{}:vdu.{}.interfaces.{}".format(db_vnfr["_id"], vdu_index,
                                                                                      iface_index)
                            if vdur.get("status") == "ERROR":
                                interface_["status"] = "ERROR"
                            interfaces.append(interface_)
        return interfaces

    def refresh(self, ro_task):
        # look for task create
        task_create_index, _ = next(i_t for i_t in enumerate(ro_task["tasks"])
                                    if i_t[1] and i_t[1]["action"] == "CREATE" and i_t[1]["status"] != "FINISHED")

        return self.new(ro_task, task_create_index, None)

    def new(self, ro_task, task_index, task_depends):

        task = ro_task["tasks"][task_index]
        task_id = task["task_id"]
        target_vim = self.my_vims[ro_task["target_id"]]

        sdn_net_id = ro_task["vim_info"]["vim_id"]

        created_items = ro_task["vim_info"].get("created_items")
        connected_ports = ro_task["vim_info"].get("connected_ports", [])
        new_connected_ports = []
        last_update = ro_task["vim_info"].get("last_update", 0)
        sdn_status = ro_task["vim_info"].get("vim_status", "BUILD") or "BUILD"
        error_list = []
        created = ro_task["vim_info"].get("created", False)

        try:

            # CREATE
            params = task["params"]
            vlds_to_connect = params["vlds"]
            associated_vim = params["target_vim"]
            additional_ports = params.get("sdn-ports") or ()  # external additional ports
            _, _, vim_account_id = associated_vim.partition(":")
            if associated_vim:
                # get associated VIM
                if associated_vim not in self.db_vims:
                    self.db_vims[associated_vim] = self.db.get_one("vim_accounts", {"_id": vim_account_id})
                db_vim = self.db_vims[associated_vim]

            # look for ports to connect
            ports = self._get_interfaces(vlds_to_connect, vim_account_id)
            # print(ports)

            sdn_ports = []
            pending_ports = error_ports = 0
            vlan_used = None
            sdn_need_update = False
            for port in ports:
                vlan_used = port.get("vlan") or vlan_used
                # TODO. Do not connect if already done
                if not port.get("compute_node") or not port.get("pci"):
                    if port.get("status") == "ERROR":
                        error_ports += 1
                    else:
                        pending_ports += 1
                    continue
                pmap = None
                compute_node_mappings = next((c for c in db_vim["config"].get("sdn-port-mapping", ())
                                             if c and c["compute_node"] == port["compute_node"]), None)
                if compute_node_mappings:
                    # process port_mapping pci of type 0000:af:1[01].[1357]
                    pmap = next((p for p in compute_node_mappings["ports"]
                                 if self._match_pci(port["pci"], p.get("pci"))), None)
                if not pmap:
                    if not db_vim["config"].get("mapping_not_needed"):
                        error_list.append("Port mapping not found for compute_node={} pci={}".format(
                            port["compute_node"], port["pci"]))
                        continue
                    pmap = {}

                service_endpoint_id = "{}:{}".format(port["compute_node"], port["pci"])
                new_port = {
                    "service_endpoint_id": pmap.get("service_endpoint_id") or service_endpoint_id,
                    "service_endpoint_encapsulation_type": "dot1q" if port["type"] == "SR-IOV" else None,
                    "service_endpoint_encapsulation_info": {
                        "vlan": port.get("vlan"),
                        "mac": port.get("mac_address"),
                        "device_id": pmap.get("device_id") or port["compute_node"],  # device_id
                        "device_interface_id": pmap.get("device_interface_id") or port["pci"],
                        "switch_dpid": pmap.get("switch_id") or pmap.get("switch_dpid"),
                        "switch_port": pmap.get("switch_port"),
                        "service_mapping_info": pmap.get("service_mapping_info"),
                    }
                }

                # TODO
                # if port["modified_at"] > last_update:
                #     sdn_need_update = True
                new_connected_ports.append(port["id"])  # TODO
                sdn_ports.append(new_port)

            if error_ports:
                error_list.append("{} interfaces have not been created as VDU is on ERROR status".format(error_ports))

            # connect external ports
            for index, additional_port in enumerate(additional_ports):
                additional_port_id = additional_port.get("service_endpoint_id") or "external-{}".format(index)
                sdn_ports.append({
                    "service_endpoint_id": additional_port_id,
                    "service_endpoint_encapsulation_type": additional_port.get("service_endpoint_encapsulation_type",
                                                                               "dot1q"),
                    "service_endpoint_encapsulation_info": {
                        "vlan": additional_port.get("vlan") or vlan_used,
                        "mac": additional_port.get("mac_address"),
                        "device_id": additional_port.get("device_id"),
                        "device_interface_id": additional_port.get("device_interface_id"),
                        "switch_dpid": additional_port.get("switch_dpid") or additional_port.get("switch_id"),
                        "switch_port": additional_port.get("switch_port"),
                        "service_mapping_info": additional_port.get("service_mapping_info"),
                    }})
                new_connected_ports.append(additional_port_id)
            sdn_info = ""
            # if there are more ports to connect or they have been modified, call create/update
            if error_list:
                sdn_status = "ERROR"
                sdn_info = "; ".join(error_list)
            elif set(connected_ports) != set(new_connected_ports) or sdn_need_update:
                last_update = time.time()
                if not sdn_net_id:
                    if len(sdn_ports) < 2:
                        sdn_status = "ACTIVE"
                        if not pending_ports:
                            self.logger.debug("task={} {} new-sdn-net done, less than 2 ports".
                                              format(task_id, ro_task["target_id"]))
                    else:
                        net_type = params.get("type") or "ELAN"
                        sdn_net_id, created_items = target_vim.create_connectivity_service(
                            net_type, sdn_ports)
                        created = True
                        self.logger.debug("task={} {} new-sdn-net={} created={}".
                                          format(task_id, ro_task["target_id"], sdn_net_id, created))
                else:
                    created_items = target_vim.edit_connectivity_service(
                        sdn_net_id, conn_info=created_items, connection_points=sdn_ports)
                    created = True
                    self.logger.debug("task={} {} update-sdn-net={} created={}".
                                      format(task_id, ro_task["target_id"], sdn_net_id, created))
                connected_ports = new_connected_ports
            elif sdn_net_id:
                wim_status_dict = target_vim.get_connectivity_service_status(sdn_net_id, conn_info=created_items)
                sdn_status = wim_status_dict["sdn_status"]
                if wim_status_dict.get("sdn_info"):
                    sdn_info = str(wim_status_dict.get("sdn_info")) or ""
                if wim_status_dict.get("error_msg"):
                    sdn_info = wim_status_dict.get("error_msg") or ""

            if pending_ports:
                if sdn_status != "ERROR":
                    sdn_info = "Waiting for getting interfaces location from VIM. Obtained '{}' of {}".format(
                        len(ports)-pending_ports, len(ports))
                if sdn_status == "ACTIVE":
                    sdn_status = "BUILD"

            ro_vim_item_update = {"vim_id": sdn_net_id,
                                  "vim_status": sdn_status,
                                  "created": created,
                                  "created_items": created_items,
                                  "connected_ports": connected_ports,
                                  "vim_details": sdn_info,
                                  "last_update": last_update}
            return sdn_status, ro_vim_item_update
        except Exception as e:
            self.logger.error("task={} vim={} new-net: {}".format(task_id, ro_task["target_id"], e),
                              exc_info=not isinstance(e, (sdnconn.SdnConnectorError, vimconn.VimConnException)))
            ro_vim_item_update = {"vim_status": "VIM_ERROR",
                                  "created": created,
                                  "vim_details": str(e)}
            return "FAILED", ro_vim_item_update

    def delete(self, ro_task, task_index):
        task = ro_task["tasks"][task_index]
        task_id = task["task_id"]
        sdn_vim_id = ro_task["vim_info"].get("vim_id")
        ro_vim_item_update_ok = {"vim_status": "DELETED",
                                 "created": False,
                                 "vim_details": "DELETED",
                                 "vim_id": None}
        try:
            if sdn_vim_id:
                target_vim = self.my_vims[ro_task["target_id"]]
                target_vim.delete_connectivity_service(sdn_vim_id, ro_task["vim_info"].get("created_items"))

        except Exception as e:
            if isinstance(e, sdnconn.SdnConnectorError) and e.http_code == HTTPStatus.NOT_FOUND.value:
                ro_vim_item_update_ok["vim_details"] = "already deleted"
            else:
                self.logger.error("ro_task={} vim={} del-sdn-net={}: {}".format(ro_task["_id"], ro_task["target_id"],
                                                                                sdn_vim_id, e),
                                  exc_info=not isinstance(e, (sdnconn.SdnConnectorError, vimconn.VimConnException)))
                ro_vim_item_update = {"vim_status": "VIM_ERROR",
                                      "vim_details": "Error while deleting: {}".format(e)}
                return "FAILED", ro_vim_item_update

        self.logger.debug("task={} {} del-sdn-net={} {}".format(task_id, ro_task["target_id"], sdn_vim_id,
                                                                ro_vim_item_update_ok.get("vim_details", "")))
        return "DONE", ro_vim_item_update_ok


class NsWorker(threading.Thread):
    REFRESH_BUILD = 5  # 5 seconds
    REFRESH_ACTIVE = 60  # 1 minute
    REFRESH_ERROR = 600
    REFRESH_IMAGE = 3600 * 10
    REFRESH_DELETE = 3600 * 10
    QUEUE_SIZE = 2000
    # TODO delete assigment_lock = Lock()
    terminate = False
    # TODO delete assignment = {}
    MAX_TIME_LOCKED = 3600
    MAX_TIME_VIM_LOCKED = 120

    def __init__(self, worker_index, config, plugins, db):
        """

        :param worker_index: thread index
        :param config: general configuration of RO, among others the process_id with the docker id where it runs
        :param plugins: global shared dict with the loaded plugins
        :param db: database class instance to use
        """
        threading.Thread.__init__(self)
        self.config = config
        self.plugins = plugins
        self.plugin_name = "unknown"
        self.logger = logging.getLogger('ro.worker{}'.format(worker_index))
        self.worker_index = worker_index
        self.task_queue = queue.Queue(self.QUEUE_SIZE)
        self.my_vims = {}   # targetvim: vimplugin class
        self.db_vims = {}   # targetvim: vim information from database
        self.vim_targets = []   # targetvim list
        self.my_id = config["process_id"] + ":" + str(worker_index)
        self.db = db
        self.item2class = {
            "net": VimInteractionNet(self.db, self.my_vims, self.db_vims, self.logger),
            "vdu": VimInteractionVdu(self.db, self.my_vims, self.db_vims, self.logger),
            "image": VimInteractionImage(self.db, self.my_vims, self.db_vims, self.logger),
            "flavor": VimInteractionFlavor(self.db, self.my_vims, self.db_vims, self.logger),
            "sdn_net": VimInteractionSdnNet(self.db, self.my_vims, self.db_vims, self.logger),
        }
        self.time_last_task_processed = None
        self.tasks_to_delete = []  # lists of tasks to delete because nsrs or vnfrs has been deleted from db

    def insert_task(self, task):
        try:
            self.task_queue.put(task, False)
            return None
        except queue.Full:
            raise NsWorkerException("timeout inserting a task")

    def terminate(self):
        self.insert_task("exit")

    def del_task(self, task):
        with self.task_lock:
            if task["status"] == "SCHEDULED":
                task["status"] = "SUPERSEDED"
                return True
            else:  # task["status"] == "processing"
                self.task_lock.release()
                return False

    def _process_vim_config(self, target_id, db_vim):
        """
        Process vim config, creating vim configuration files as ca_cert
        :param target_id: vim/sdn/wim + id
        :param db_vim: Vim dictionary obtained from database
        :return: None. Modifies vim. Creates a folder target_id:worker_index and several files
        """
        if not db_vim.get("config"):
            return
        file_name = ""
        try:
            if db_vim["config"].get("ca_cert_content"):
                file_name = "{}:{}".format(target_id, self.worker_index)
                try:
                    mkdir(file_name)
                except FileExistsError:
                    pass
                file_name = file_name + "/ca_cert"
                with open(file_name, "w") as f:
                    f.write(db_vim["config"]["ca_cert_content"])
                    del db_vim["config"]["ca_cert_content"]
                    db_vim["config"]["ca_cert"] = file_name
        except Exception as e:
            raise NsWorkerException("Error writing to file '{}': {}".format(file_name, e))

    def _load_plugin(self, name, type="vim"):
        # type can be vim or sdn
        if "rovim_dummy" not in self.plugins:
            self.plugins["rovim_dummy"] = VimDummyConnector
        if "rosdn_dummy" not in self.plugins:
            self.plugins["rosdn_dummy"] = SdnDummyConnector
        if name in self.plugins:
            return self.plugins[name]
        try:
            for v in iter_entry_points('osm_ro{}.plugins'.format(type), name):
                self.plugins[name] = v.load()
        except Exception as e:
            raise NsWorkerException("Cannot load plugin osm_{}: {}".format(name, e))
        if name and name not in self.plugins:
            raise NsWorkerException("Plugin 'osm_{n}' has not been installed".format(n=name))
        return self.plugins[name]

    def _unload_vim(self, target_id):
        """
        Unload a vim_account. Removes it from self db_vims dictionary, my_vims dictionary and vim_targets list
        :param target_id: Contains type:_id; where type can be 'vim', ...
        :return: None.
        """
        try:
            target, _, _id = target_id.partition(":")
            self.db_vims.pop(target_id, None)
            self.my_vims.pop(target_id, None)
            self.vim_targets.remove(target_id)
            rmtree("{}:{}".format(target_id, self.worker_index))
        except FileNotFoundError:
            pass  # this is raised by rmtree if folder does not exist
        except Exception as e:
            self.logger.error("Cannot unload {}: {}".format(target_id, e))

    def _check_vim(self, target_id):
        """
        Load a VIM/SDN/WIM (if not loaded) and check connectivity, updating database with ENABLE or ERROR
        :param target_id: Contains type:_id; type can be 'vim', 'sdn' or 'wim'
        :return: None.
        """
        target, _, _id = target_id.partition(":")
        now = time.time()
        update_dict = {}
        unset_dict = {}
        op_text = ""
        step = ""
        loaded = target_id in self.my_vims
        target_database = "vim_accounts" if target == "vim" else "wim_accounts" if target == "wim" else "sdns"
        try:
            step = "Getting {} from db".format(target_id)
            db_vim = self.db.get_one(target_database, {"_id": _id})
            for op_index, operation in enumerate(db_vim["_admin"].get("operations", ())):
                if operation["operationState"] != "PROCESSING":
                    continue
                locked_at = operation.get("locked_at")
                if locked_at is not None and locked_at >= now - self.MAX_TIME_VIM_LOCKED:
                    # some other thread is doing this operation
                    return
                # lock
                op_text = "_admin.operations.{}.".format(op_index)
                if not self.db.set_one(target_database,
                                       q_filter={"_id": _id,
                                                 op_text + "operationState": "PROCESSING",
                                                 op_text + "locked_at": locked_at
                                                 },
                                       update_dict={op_text + "locked_at": now,
                                                    "admin.current_operation": op_index},
                                       fail_on_empty=False):
                    return
                unset_dict[op_text + "locked_at"] = None
                unset_dict["current_operation"] = None
                step = "Loading " + target_id
                error_text = self._load_vim(target_id)
                if not error_text:
                    step = "Checking connectivity"
                    if target == 'vim':
                        self.my_vims[target_id].check_vim_connectivity()
                    else:
                        self.my_vims[target_id].check_credentials()
                update_dict["_admin.operationalState"] = "ENABLED"
                update_dict["_admin.detailed-status"] = ""
                unset_dict[op_text + "detailed-status"] = None
                update_dict[op_text + "operationState"] = "COMPLETED"
                return

        except Exception as e:
            error_text = "{}: {}".format(step, e)
            self.logger.error("{} for {}: {}".format(step, target_id, e))

        finally:
            if update_dict or unset_dict:
                if error_text:
                    update_dict[op_text + "operationState"] = "FAILED"
                    update_dict[op_text + "detailed-status"] = error_text
                    unset_dict.pop(op_text + "detailed-status", None)
                    update_dict["_admin.operationalState"] = "ERROR"
                    update_dict["_admin.detailed-status"] = error_text
                if op_text:
                    update_dict[op_text + "statusEnteredTime"] = now
                self.db.set_one(target_database, q_filter={"_id": _id}, update_dict=update_dict, unset=unset_dict,
                                fail_on_empty=False)
            if not loaded:
                self._unload_vim(target_id)

    def _reload_vim(self, target_id):
        if target_id in self.vim_targets:
            self._load_vim(target_id)
        else:
            # if the vim is not loaded, but database information of VIM is cached at self.db_vims,
            # just remove it to force load again next time it is needed
            self.db_vims.pop(target_id, None)

    def _load_vim(self, target_id):
        """
        Load or reload a vim_account, sdn_controller or wim_account.
        Read content from database, load the plugin if not loaded.
        In case of error loading the plugin, it load a failing VIM_connector
        It fills self db_vims dictionary, my_vims dictionary and vim_targets list
        :param target_id: Contains type:_id; where type can be 'vim', ...
        :return: None if ok, descriptive text if error
        """
        target, _, _id = target_id.partition(":")
        target_database = "vim_accounts" if target == "vim" else "wim_accounts" if target == "wim" else "sdns"
        plugin_name = ""
        vim = None
        try:
            step = "Getting {}={} from db".format(target, _id)
            # TODO process for wim, sdnc, ...
            vim = self.db.get_one(target_database, {"_id": _id})

            # if deep_get(vim, "config", "sdn-controller"):
            #     step = "Getting sdn-controller-id='{}' from db".format(vim["config"]["sdn-controller"])
            #     db_sdn = self.db.get_one("sdns", {"_id": vim["config"]["sdn-controller"]})

            step = "Decrypting password"
            schema_version = vim.get("schema_version")
            self.db.encrypt_decrypt_fields(vim, "decrypt", fields=('password', 'secret'),
                                           schema_version=schema_version, salt=_id)
            self._process_vim_config(target_id, vim)
            if target == "vim":
                plugin_name = "rovim_" + vim["vim_type"]
                step = "Loading plugin '{}'".format(plugin_name)
                vim_module_conn = self._load_plugin(plugin_name)
                step = "Loading {}'".format(target_id)
                self.my_vims[target_id] = vim_module_conn(
                    uuid=vim['_id'], name=vim['name'],
                    tenant_id=vim.get('vim_tenant_id'), tenant_name=vim.get('vim_tenant_name'),
                    url=vim['vim_url'], url_admin=None,
                    user=vim['vim_user'], passwd=vim['vim_password'],
                    config=vim.get('config') or {}, persistent_info={}
                )
            else:  # sdn
                plugin_name = "rosdn_" + vim["type"]
                step = "Loading plugin '{}'".format(plugin_name)
                vim_module_conn = self._load_plugin(plugin_name, "sdn")
                step = "Loading {}'".format(target_id)
                wim = deepcopy(vim)
                wim_config = wim.pop("config", {}) or {}
                wim["uuid"] = wim["_id"]
                wim["wim_url"] = wim["url"]
                if wim.get("dpid"):
                    wim_config["dpid"] = wim.pop("dpid")
                if wim.get("switch_id"):
                    wim_config["switch_id"] = wim.pop("switch_id")
                self.my_vims[target_id] = vim_module_conn(wim, wim, wim_config)  # wim, wim_account, config
            self.db_vims[target_id] = vim
            self.error_status = None
            self.logger.info("Connector loaded for {}, plugin={}".format(target_id, plugin_name))
        except Exception as e:
            self.logger.error("Cannot load {} plugin={}: {} {}".format(
                target_id, plugin_name, step, e))
            self.db_vims[target_id] = vim or {}
            self.db_vims[target_id] = FailingConnector(str(e))
            error_status = "{} Error: {}".format(step, e)
            return error_status
        finally:
            if target_id not in self.vim_targets:
                self.vim_targets.append(target_id)

    def _get_db_task(self):
        """
        Read actions from database and reload them at memory. Fill self.refresh_list, pending_list, vim_actions
        :return: None
        """
        now = time.time()
        if not self.time_last_task_processed:
            self.time_last_task_processed = now
        try:
            while True:
                locked = self.db.set_one(
                    "ro_tasks",
                    q_filter={"target_id": self.vim_targets,
                              "tasks.status": ['SCHEDULED', 'BUILD', 'DONE', 'FAILED'],
                              "locked_at.lt": now - self.MAX_TIME_LOCKED,
                              "to_check_at.lt": self.time_last_task_processed},
                    update_dict={"locked_by": self.my_id, "locked_at": now},
                    fail_on_empty=False)
                if locked:
                    # read and return
                    ro_task = self.db.get_one(
                        "ro_tasks",
                        q_filter={"target_id": self.vim_targets,
                                  "tasks.status": ['SCHEDULED', 'BUILD', 'DONE', 'FAILED'],
                                  "locked_at": now})
                    return ro_task
                if self.time_last_task_processed == now:
                    self.time_last_task_processed = None
                    return None
                else:
                    self.time_last_task_processed = now
                    # self.time_last_task_processed = min(self.time_last_task_processed + 1000, now)

        except DbException as e:
            self.logger.error("Database exception at _get_db_task: {}".format(e))
        except Exception as e:
            self.logger.critical("Unexpected exception at _get_db_task: {}".format(e), exc_info=True)
        return None

    def _delete_task(self, ro_task, task_index, task_depends, db_update):
        """
        Determine if this task need to be done or superseded
        :return: None
        """
        my_task = ro_task["tasks"][task_index]
        task_id = my_task["task_id"]
        needed_delete = ro_task["vim_info"]["created"] or ro_task["vim_info"].get("created_items", False)
        if my_task["status"] == "FAILED":
            return None, None  # TODO need to be retry??
        try:
            for index, task in enumerate(ro_task["tasks"]):
                if index == task_index or not task:
                    continue  # own task
                if my_task["target_record"] == task["target_record"] and task["action"] == "CREATE":
                    # set to finished
                    db_update["tasks.{}.status".format(index)] = task["status"] = "FINISHED"
                elif task["action"] == "CREATE" and task["status"] not in ("FINISHED", "SUPERSEDED"):
                    needed_delete = False
            if needed_delete:
                return self.item2class[my_task["item"]].delete(ro_task, task_index)
            else:
                return "SUPERSEDED", None
        except Exception as e:
            if not isinstance(e, NsWorkerException):
                self.logger.critical("Unexpected exception at _delete_task task={}: {}".format(task_id, e),
                                     exc_info=True)
            return "FAILED", {"vim_status": "VIM_ERROR", "vim_details": str(e)}

    def _create_task(self, ro_task, task_index, task_depends, db_update):
        """
        Determine if this task need to create something at VIM
        :return: None
        """
        my_task = ro_task["tasks"][task_index]
        task_id = my_task["task_id"]
        task_status = None
        if my_task["status"] == "FAILED":
            return None, None  # TODO need to be retry??
        elif my_task["status"] == "SCHEDULED":
            # check if already created by another task
            for index, task in enumerate(ro_task["tasks"]):
                if index == task_index or not task:
                    continue  # own task
                if task["action"] == "CREATE" and task["status"] not in ("SCHEDULED", "FINISHED", "SUPERSEDED"):
                    return task["status"], "COPY_VIM_INFO"

            try:
                task_status, ro_vim_item_update = self.item2class[my_task["item"]].new(
                    ro_task, task_index, task_depends)
                # TODO update other CREATE tasks
            except Exception as e:
                if not isinstance(e, NsWorkerException):
                    self.logger.error("Error executing task={}: {}".format(task_id, e), exc_info=True)
                task_status = "FAILED"
                ro_vim_item_update = {"vim_status": "VIM_ERROR", "vim_details": str(e)}
                # TODO update    ro_vim_item_update
            return task_status, ro_vim_item_update
        else:
            return None, None

    def _get_dependency(self, task_id, ro_task=None, target_id=None):
        """
        Look for dependency task
        :param task_id: Can be one of
            1. target_vim+blank+task.target_record_id: "(vim|sdn|wim):<id> (vnfrs|nsrs):(vld|vdu|flavor|image).<id>"
            2. task.target_record_id: "(vnfrs|nsrs):(vld|vdu|flavor|image).<id>"
            3. task.task_id: "<action_id>:number"
        :param ro_task:
        :param target_id:
        :return: database ro_task plus index of task
        """
        if task_id.startswith("vim:") or task_id.startswith("sdn:") or task_id.startswith("wim:"):
            target_id, _, task_id = task_id.partition(" ")

        if task_id.startswith("nsrs:") or task_id.startswith("vnfrs:"):
            ro_task_dependency = self.db.get_one(
                "ro_tasks",
                q_filter={"target_id": target_id,
                          "tasks.target_record_id": task_id
                          },
                fail_on_empty=False)
            if ro_task_dependency:
                for task_index, task in enumerate(ro_task_dependency["tasks"]):
                    if task["target_record_id"] == task_id:
                        return ro_task_dependency, task_index

        else:
            if ro_task:
                for task_index, task in enumerate(ro_task["tasks"]):
                    if task and task["task_id"] == task_id:
                        return ro_task, task_index
            ro_task_dependency = self.db.get_one(
                "ro_tasks",
                q_filter={"tasks.ANYINDEX.task_id": task_id,
                          "tasks.ANYINDEX.target_record.ne": None
                          },
                fail_on_empty=False)
            if ro_task_dependency:
                for task_index, task in ro_task_dependency["tasks"]:
                    if task["task_id"] == task_id:
                        return ro_task_dependency, task_index
        raise NsWorkerException("Cannot get depending task {}".format(task_id))

    def _process_pending_tasks(self, ro_task):
        ro_task_id = ro_task["_id"]
        now = time.time()
        next_check_at = now + (24*60*60)   # one day
        db_ro_task_update = {}

        def _update_refresh(new_status):
            # compute next_refresh
            nonlocal task
            nonlocal next_check_at
            nonlocal db_ro_task_update
            nonlocal ro_task

            next_refresh = time.time()
            if task["item"] in ("image", "flavor"):
                next_refresh += self.REFRESH_IMAGE
            elif new_status == "BUILD":
                next_refresh += self.REFRESH_BUILD
            elif new_status == "DONE":
                next_refresh += self.REFRESH_ACTIVE
            else:
                next_refresh += self.REFRESH_ERROR
            next_check_at = min(next_check_at, next_refresh)
            db_ro_task_update["vim_info.refresh_at"] = next_refresh
            ro_task["vim_info"]["refresh_at"] = next_refresh

        try:
            # 0 get task_status_create
            task_status_create = None
            task_create = next((t for t in ro_task["tasks"] if t and t["action"] == "CREATE" and
                                t["status"] in ("BUILD", "DONE")), None)
            if task_create:
                task_status_create = task_create["status"]
            # 1. look for tasks in status SCHEDULED, or in status CREATE if action is  DONE or BUILD
            for task_action in ("DELETE", "CREATE", "EXEC"):
                db_vim_update = None
                new_status = None
                for task_index, task in enumerate(ro_task["tasks"]):
                    if not task:
                        continue  # task deleted
                    target_update = None
                    if (task_action in ("DELETE", "EXEC") and task["status"] not in ("SCHEDULED", "BUILD")) or \
                            task["action"] != task_action or \
                            (task_action == "CREATE" and task["status"] in ("FINISHED", "SUPERSEDED")):
                        continue
                    task_path = "tasks.{}.status".format(task_index)
                    try:
                        db_vim_info_update = None
                        if task["status"] == "SCHEDULED":
                            task_depends = {}
                            # check if tasks that this depends on have been completed
                            dependency_not_completed = False
                            for dependency_task_id in (task.get("depends_on") or ()):
                                dependency_ro_task, dependency_task_index = \
                                    self._get_dependency(dependency_task_id, target_id=ro_task["target_id"])
                                dependency_task = dependency_ro_task["tasks"][dependency_task_index]
                                if dependency_task["status"] == "SCHEDULED":
                                    dependency_not_completed = True
                                    next_check_at = min(next_check_at, dependency_ro_task["to_check_at"])
                                    break
                                elif dependency_task["status"] == "FAILED":
                                    error_text = "Cannot {} {} because depends on failed {} {} id={}): {}".format(
                                        task["action"], task["item"], dependency_task["action"],
                                        dependency_task["item"], dependency_task_id,
                                        dependency_ro_task["vim_info"].get("vim_details"))
                                    self.logger.error("task={} {}".format(task["task_id"], error_text))
                                    raise NsWorkerException(error_text)

                                task_depends[dependency_task_id] = dependency_ro_task["vim_info"]["vim_id"]
                                task_depends["TASK-{}".format(dependency_task_id)] = \
                                    dependency_ro_task["vim_info"]["vim_id"]
                            if dependency_not_completed:
                                # TODO set at vim_info.vim_details that it is waiting
                                continue

                        if task["action"] == "DELETE":
                            new_status, db_vim_info_update = self._delete_task(ro_task, task_index,
                                                                               task_depends, db_ro_task_update)
                            new_status = "FINISHED" if new_status == "DONE" else new_status
                            # ^with FINISHED instead of DONE it will not be refreshing
                            if new_status in ("FINISHED", "SUPERSEDED"):
                                target_update = "DELETE"
                        elif task["action"] == "EXEC":
                            new_status, db_vim_info_update, db_task_update = self.item2class[task["item"]].exec(
                                ro_task, task_index, task_depends)
                            new_status = "FINISHED" if new_status == "DONE" else new_status
                            # ^with FINISHED instead of DONE it will not be refreshing
                            if db_task_update:
                                # load into database the modified db_task_update "retries" and "next_retry"
                                if db_task_update.get("retries"):
                                    db_ro_task_update["tasks.{}.retries".format(task_index)] = db_task_update["retries"]
                                next_check_at = time.time() + db_task_update.get("next_retry", 60)
                            target_update = None
                        elif task["action"] == "CREATE":
                            if task["status"] == "SCHEDULED":
                                if task_status_create:
                                    new_status = task_status_create
                                    target_update = "COPY_VIM_INFO"
                                else:
                                    new_status, db_vim_info_update = \
                                        self.item2class[task["item"]].new(ro_task, task_index, task_depends)
                                    # self._create_task(ro_task, task_index, task_depends, db_ro_task_update)
                                    _update_refresh(new_status)
                            else:
                                if ro_task["vim_info"]["refresh_at"] and now > ro_task["vim_info"]["refresh_at"]:
                                    new_status, db_vim_info_update = self.item2class[task["item"]].refresh(ro_task)
                                    _update_refresh(new_status)
                    except Exception as e:
                        new_status = "FAILED"
                        db_vim_info_update = {"vim_status": "VIM_ERROR", "vim_details": str(e)}
                        if not isinstance(e, (NsWorkerException, vimconn.VimConnException)):
                            self.logger.error("Unexpected exception at _delete_task task={}: {}".
                                              format(task["task_id"], e), exc_info=True)

                    try:
                        if db_vim_info_update:
                            db_vim_update = db_vim_info_update.copy()
                            db_ro_task_update.update({"vim_info." + k: v for k, v in db_vim_info_update.items()})
                            ro_task["vim_info"].update(db_vim_info_update)

                        if new_status:
                            if task_action == "CREATE":
                                task_status_create = new_status
                            db_ro_task_update[task_path] = new_status
                        if target_update or db_vim_update:

                            if target_update == "DELETE":
                                self._update_target(task, None)
                            elif target_update == "COPY_VIM_INFO":
                                self._update_target(task, ro_task["vim_info"])
                            else:
                                self._update_target(task, db_vim_update)

                    except Exception as e:
                        if isinstance(e, DbException) and e.http_code == HTTPStatus.NOT_FOUND:
                            # if the vnfrs or nsrs has been removed from database, this task must be removed
                            self.logger.debug("marking to delete task={}".format(task["task_id"]))
                            self.tasks_to_delete.append(task)
                        else:
                            self.logger.error("Unexpected exception at _update_target task={}: {}".
                                              format(task["task_id"], e), exc_info=True)

            q_filter = {"_id": ro_task["_id"], "to_check_at": ro_task["to_check_at"], "locked_at": ro_task["locked_at"]}
            # modify own task. Try filtering by to_next_check. For race condition if to_check_at has been modified,
            # outside this task (by ro_nbi) do not update it
            db_ro_task_update["locked_by"] = None
            # locked_at converted to int only for debugging. When has not decimals it means it has been unlocked
            db_ro_task_update["locked_at"] = int(now - self.MAX_TIME_LOCKED)
            db_ro_task_update["to_check_at"] = next_check_at
            if not self.db.set_one("ro_tasks",
                                   update_dict=db_ro_task_update,
                                   q_filter=q_filter,
                                   fail_on_empty=False):
                del db_ro_task_update["to_check_at"]
                del q_filter["to_check_at"]
                self.db.set_one("ro_tasks",
                                q_filter=q_filter,
                                update_dict=db_ro_task_update,
                                fail_on_empty=True)
        except DbException as e:
            self.logger.error("ro_task={} Error updating database {}".format(ro_task_id, e))
        except Exception as e:
            self.logger.error("Error executing ro_task={}: {}".format(ro_task_id, e), exc_info=True)

    def _update_target(self, task, ro_vim_item_update):
        table, _, temp = task["target_record"].partition(":")
        _id, _, path_vim_status = temp.partition(":")
        path_item = path_vim_status[:path_vim_status.rfind(".")]
        path_item = path_item[:path_item.rfind(".")]
        # path_vim_status: dot separated list targeting vim information, e.g. "vdur.10.vim_info.vim:id"
        # path_item: dot separated list targeting record information, e.g. "vdur.10"
        if ro_vim_item_update:
            update_dict = {path_vim_status + "." + k: v for k, v in ro_vim_item_update.items() if k in
                           ('vim_id', 'vim_details', 'vim_name', 'vim_status', 'interfaces')}
            if path_vim_status.startswith("vdur."):
                # for backward compatibility, add vdur.name apart from vdur.vim_name
                if ro_vim_item_update.get("vim_name"):
                    update_dict[path_item + ".name"] = ro_vim_item_update["vim_name"]
                # for backward compatibility, add vdur.vim-id apart from vdur.vim_id
                if ro_vim_item_update.get("vim_id"):
                    update_dict[path_item + ".vim-id"] = ro_vim_item_update["vim_id"]
                # update general status
                if ro_vim_item_update.get("vim_status"):
                    update_dict[path_item + ".status"] = ro_vim_item_update["vim_status"]
            if ro_vim_item_update.get("interfaces"):
                path_interfaces = path_item + ".interfaces"
                for i, iface in enumerate(ro_vim_item_update.get("interfaces")):
                    if iface:
                        update_dict.update({path_interfaces + ".{}.".format(i) + k: v for k, v in iface.items() if
                                            k in ('vlan', 'compute_node', 'pci')})
                        # put ip_address and mac_address with ip-address and mac-address
                        if iface.get('ip_address'):
                            update_dict[path_interfaces + ".{}.".format(i) + "ip-address"] = iface['ip_address']
                        if iface.get('mac_address'):
                            update_dict[path_interfaces + ".{}.".format(i) + "mac-address"] = iface['mac_address']
                        if iface.get("mgmt_vnf_interface") and iface.get("ip_address"):
                            update_dict["ip-address"] = iface.get("ip_address").split(";")[0]
                        if iface.get("mgmt_vdu_interface") and iface.get("ip_address"):
                            update_dict[path_item + ".ip-address"] = iface.get("ip_address").split(";")[0]

            self.db.set_one(table, q_filter={"_id": _id}, update_dict=update_dict)
        else:
            update_dict = {path_item + ".status": "DELETED"}
            self.db.set_one(table, q_filter={"_id": _id}, update_dict=update_dict, unset={path_vim_status: None})

    def _process_delete_db_tasks(self):
        """
        Delete task from database because vnfrs or nsrs or both have been deleted
        :return: None. Uses and modify self.tasks_to_delete
        """
        while self.tasks_to_delete:
            task = self.tasks_to_delete[0]
            vnfrs_deleted = None
            nsr_id = task["nsr_id"]
            if task["target_record"].startswith("vnfrs:"):
                # check if nsrs is present
                if self.db.get_one("nsrs", {"_id": nsr_id}, fail_on_empty=False):
                    vnfrs_deleted = task["target_record"].split(":")[1]
            try:
                self.delete_db_tasks(self.db, nsr_id, vnfrs_deleted)
            except Exception as e:
                self.logger.error("Error deleting task={}: {}".format(task["task_id"], e))
            self.tasks_to_delete.pop(0)

    @staticmethod
    def delete_db_tasks(db, nsr_id, vnfrs_deleted):
        """
        Static method because it is called from osm_ng_ro.ns
        :param db: instance of database to use
        :param nsr_id: affected nsrs id
        :param vnfrs_deleted: only tasks with this vnfr id. If None, all affected by nsr_id
        :return: None, exception is fails
        """
        retries = 5
        for retry in range(retries):
            ro_tasks = db.get_list("ro_tasks", {"tasks.nsr_id": nsr_id})
            now = time.time()
            conflict = False
            for ro_task in ro_tasks:
                db_update = {}
                to_delete_ro_task = True
                for index, task in enumerate(ro_task["tasks"]):
                    if not task:
                        pass
                    elif (not vnfrs_deleted and task["nsr_id"] == nsr_id) or \
                            (vnfrs_deleted and task["target_record"].startswith("vnfrs:"+vnfrs_deleted)):
                        db_update["tasks.{}".format(index)] = None
                    else:
                        to_delete_ro_task = False  # used by other nsr, ro_task cannot be deleted
                # delete or update if nobody has changed ro_task meanwhile. Used modified_at for known if changed
                if to_delete_ro_task:
                    if not db.del_one("ro_tasks",
                                      q_filter={"_id": ro_task["_id"], "modified_at": ro_task["modified_at"]},
                                      fail_on_empty=False):
                        conflict = True
                elif db_update:
                    db_update["modified_at"] = now
                    if not db.set_one("ro_tasks",
                                      q_filter={"_id": ro_task["_id"], "modified_at": ro_task["modified_at"]},
                                      update_dict=db_update,
                                      fail_on_empty=False):
                        conflict = True
            if not conflict:
                return
        else:
            raise NsWorkerException("Exceeded {} retries".format(retries))

    def run(self):
        # load database
        self.logger.debug("Starting")
        while True:
            # step 1: get commands from queue
            try:
                task = self.task_queue.get(block=False if self.my_vims else True)
                if task[0] == "terminate":
                    break
                elif task[0] == "load_vim":
                    self._load_vim(task[1])
                elif task[0] == "unload_vim":
                    self._unload_vim(task[1])
                elif task[0] == "reload_vim":
                    self._reload_vim(task[1])
                elif task[0] == "check_vim":
                    self._check_vim(task[1])
                continue
            except Exception as e:
                if isinstance(e, queue.Empty):
                    pass
                else:
                    self.logger.critical("Error processing task: {}".format(e), exc_info=True)

            # step 2: process pending_tasks, delete not needed tasks
            try:
                if self.tasks_to_delete:
                    self._process_delete_db_tasks()
                busy = False
                ro_task = self._get_db_task()
                if ro_task:
                    self._process_pending_tasks(ro_task)
                    busy = True
                if not busy:
                    time.sleep(5)
            except Exception as e:
                self.logger.critical("Unexpected exception at run: " + str(e), exc_info=True)

        self.logger.debug("Finishing")